Progression to Lymph Node Metastasis After Spontaneous Regression of Pulmonary Adenocarcinoma Following Biopsy

BACKGROUND/AIM

Spontaneous regression (SR) of cancer, which indicates the natural disappearance of malignant tumors, is rare. Little is known about the mechanisms underlying SR; however, immunological reactions, infections, injuries, and medications have been presumed. Among previously reported cases of SR, lung cancer cases have been extremely limited.

CASE REPORT

Here, we present a case of lymph node metastasis exacerbation after SR of a primary adenocarcinoma following a biopsy. After complete disappearance of the primary site tumor, metastatic lymph nodes in the mediastinum gradually increased in size as a single lesion. Local treatment with resection and radiotherapy was effective for this metastasis, without recurrence for >3 years.

CONCLUSION

This is an interesting case of SR of pulmonary adenocarcinoma with inconsistent features in the primary and metastatic lesions. When physicians encounter exacerbation of metastatic sites with SR of the primary site in lung cancer, local intervention may be considered as a curative treatment.

Spontaneous regression of multiple solitary plasmacytoma harboring Epstein-Barr virus: a case report and literature review

We report a rare case of spontaneous regression (SR) in an elderly untreated patient with multiple solitary plasmacytoma (MSP). Diagnosis of MSP was confirmed through surgical resection of the left nasal cavity mass and subsequent biopsy of the right humerus. The patient was considered ineligible for chemotherapy due to poor performance status. At 3-month post-diagnosis, the patient's condition worsened with deteriorating bone lesions and emergence of a new serum monoclonal protein. However, these clinical findings completely disappeared at 6 months, and positron emission tomography-computed tomography at 1 year confirmed complete metabolic remission. Notably, peripheral blood lymphocyte counts were inversely correlated with tumor progression and remission. Pathological re-evaluation of the initial biopsy specimens revealed programmed cell death protein 1 (PD-1) expression in tumor-infiltrating CD8+ T cells. In addition, tumor cells were infected with Epstein-Barr virus (EBV) but were negative for programmed cell death ligand 1 (PD-L1) expression, which is the most potent immune escape mechanism in tumor cells. While the mechanism underlying SR remains unclear, our findings suggest that host immune response as well as EBV infection may contribute to SR. Further studies are needed to elucidate the clinicopathologic mechanisms of tumor regression in plasma cell neoplasms.

Spontaneous regression of an epidermoid cyst in a pediatric patient-Case report and review of the literature

Epidermoid cysts are infrequent, benign, slow-growing, space-occupying lesions that account for 0.5-1.8% of primary intracranial tumors. We report the case of a 17-month-old child who presented in 2015 for one episode of pallor associated with hypotonia. Epilepsy was excluded and MRI was recommended. The MRI was performed and there were no focal parenchymal lesions, but it showed an extra-axial ovoid lesion with imaging characteristics consistent with epidermoid cyst. Follow-up MRI at one year was performed and it showed minimal increased in dimensions of the cyst, without changes into the signal of the lesion. Another MRI was performed 7 years after and it showed complete resolution of the cyst. Six months afterwards, another MRI was performed and it confirmed the complete regression of the cyst, without any extra-axial masses reported. The patient did not present any neurological anomalies. No follow-up MRI was recommended afterwards. Spontaneous regression of epidermoid cyst in pediatric population is an extremely rare event, but it should be taken into account when the patient shows no symptoms. This is the third case of spontaneous regression of an epidermoid cyst reported in pediatric patients, and the first one in the temporal region. Careful follow-up and watchful waiting could be an option to surgical treatment in epidermoid cysts.

Spontaneous regression of small cell lung cancer associated with Lambert-Eaton Myasthenic Syndrome: Case report

Spontaneous regression (SR) of cancer is very rare, especially of small cell lung cancer (SCLC). Recently, an association of paraneoplastic neurological syndrome (PNS) has been reported as a cause of SR of cancer, and onconeural antibodies are a possible factor in the SR of cancer associated with PNS. We herein report the first case of SR of SCLC combined with anti-P/Q-type of voltage-gated calcium channel (VGCC) antibody-positive Lambert-Eaton myasthenic syndrome (LEMS), a subtype of PNS. This case report suggests that SCLC may be spontaneously reduced by an autoimmune response induced by VGCC antibodies associated with LEMS. Our finding may help elucidate the mechanisms that inhibit tumor growth and cause the regression of tumors.

Pathologically confirmed spontaneous regression of small cell lung cancer after computed tomography-guided percutaneous transthoracic needle biopsy followed by surgery

BACKGROUND

Spontaneous regression of malignant tumors is a rare phenomenon, especially in primary lung cancer. The underlying mechanisms remain unclear, but they may often involve immunological mechanisms.

CASE PRESENTATION

In January 2020, a 78-year-old female underwent examination during follow-up of interstitial pneumonia. Chest X-ray and computed tomography (CT) scan revealed a 1.2 × 1.2 cm nodule in the left lower lobe. Based on CT-guided percutaneous transthoracic needle biopsy (PTNB), it was diagnosed as small cell lung cancer (SCLC). Immunohistochemical staining showed that tumor cells were positive for CD56, synaptophysin, and chromogranin A. Twenty-three days after the CT-guided PTNB, repeat CT scan showed that the tumor size regressed to 0.6 × 0.6 cm. The tumor showed positive uptake in fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT. The maximum standardized uptake value of the nodule was 2.24. PET-CT and enhanced magnetic resonance imaging of the brain showed no distant or lymph node metastasis. The patient's preoperative disease was diagnosed as cT1aN0M0, stageIA1, SCLC. In March 2020, she underwent left lower lobectomy and mediastinal lymph node dissection. Pathological examination of the resected specimen showed that the small tumor cells were dense with a high nucleus to cytoplasm ratio, and the morphological diagnosis was small cell carcinoma. The resected tumor size regressed to 0.05 × 0.02 cm, and no lymph node metastasis was observed. Because it was extremely small, immunohistochemical staining could not be conducted. Active fibrosis and inflammation were present around the tumor. Finally, the patient was pathologically diagnosed as SCLC pT1miN0M0, stage IA1. The patient is alive without recurrence 23 months after surgery with no adjuvant therapy.

CONCLUSIONS

We present a rare surgical case of pathologically confirmed spontaneous regression of SCLC after CT-guided PTNB. Although spontaneous regression is extremely rare, we should recognize this phenomenon.

Spontaneous regression of an isolated retinal astrocytic hamartoma in a newborn: a case report

BACKGROUND

To report the spontaneous regression of an isolated retinal astrocytic hamartoma in a newborn. During the seven-month follow-up duration, fundus photography and fluorescein angiography examinations were performed.

CASE PRESENTATION

An isolated retinal astrocytic hamartoma was detected in the nasal retina of the left eye of a 4-day-old male infant. At the time of initial presentation, we detected a solitary yellowish-white flat mass with an approximate size of 1.5 disc diameters in the nasal retina. Fluorescein angiography (FA) revealed a diffuse hyperfluorescence with slight fluorescence leakage. Seven months later, the fundus examination showed no lesion in the left eye, FA revealed mild tortuous vessels without leakage.

CONCLUSIONS

In the present case, we established that the isolated retinal astrocytic hamartoma in this infant has underwent spontaneous regression. This case can point out that follow -up reexaminations are advisable for a solitary yellowish-white flat mass of the fundus in a newborn.

Spontaneous complete regression of malignant cavernous sinus dural arteriovenous fistula following partial transarterial embolization with liquid embolic material: Report of two cases

Background

Spontaneous complete regression of malignant cavernous sinus dural arteriovenous fistulas (CSDAVFs) following partial transarterial embolization is an extremely uncommon phenomenon. The mechanism responsible for this condition remains unclear.

Case Description

The authors describe two cases of malignant CSDAVFs (Cognard IIb and V) treated by partial transarterial embolization with liquid embolic agents after unsuccessful transvenous embolization through various routes. Follow-up cerebral angiography in these cases confirmed complete resolution of the fistulas.

Conclusion

In our two patients harboring low-flow CSDAVFs with preexisting thrombosis of the cavernous sinus (CS), it is possible that some portions of the liquid embolic materials could migrate into the fistulas, inducing thrombosis within the CS.

Regression of a large prolapsed lumbar disc herniation achieved by conservative treatment: A case report and literature review

A common spinal condition known as lumbar disc herniation (LDH) can result in radicular and low back discomfort. A 27-year-old man was admitted to our hospital with a 6-year history of persistent low back pain, and his low back pain had recurred with radiation to his lower extremities over the last two months. An extensive right-sided paracentral disc herniation in the L5/S1 intervertebral region, which compressed the nerve root, was discovered by magnetic resonance imaging (MRI) of his lumbar spine. After receiving conservative treatment, the patient reported that his lower back discomfort and neurogenic claudication had gradually subsided after 4 months. After one year, a follow-up MRI showed that the massive, prolapsed disc herniation at the L5/S1 level had totally disappeared. The sagittal protrusion length of the L5/S1 intervertebral disc shrank from 12.35 mm to 3.49 mm. However, there remained a chance of vertebral height loss. During the course of treatment, the height of the L5/S1 intervertebral space was still slightly reduced. The intervertebral space height declined from 7.705 mm to 7.201 mm after one year of treatment. The current case and a review of the literature demonstrate that LDH can decrease with conservative therapy over a short period of time. We stress the effectiveness of conservative treatment in very select LDH cases that lack a clear surgical justification.

Spontaneous remission of angioimmunoblastic T-cell lymphoma in a child with ataxia-telangiectasia: a case report

BACKGROUND

Angioimmunoblastic T-cell lymphoma is an uncommon subtype of peripheral T-cell lymphoma in children with fewer than 20 cases reported in literature.

CASE PRESENTATION

A 3-year-old Omani boy was diagnosed with ataxia-talengectasia presenting with fever and generalized lymphadenopathy. His biopsy revealed atypical lymphocytic infiltrate consistent with the diagnosis of angioimmunoblastic T-cell lymphoma. Within 3 weeks from the initial presentation and without any neoadjuvant therapy, he showed complete recovery of symptoms with absence of fever and regression of all previously affected lymph nodes. He has remained in remission ever since.

CONCLUSION

This is the first report of spontaneous improvement of angioimmunoblastic T-cell lymphoma in a patient with ataxia-telangiectasia who was 3 years old at presentation. Owing to the paucity of similar cases, this report adds valuable diagnostic, therapeutic, and monitoring data.

A vanished gastric gastrointestinal stromal tumor

BACKGROUND

Local resection is the standard treatment for gastrointestinal stromal tumors (GISTs). Laparoscopic and endoscopic cooperative surgery (LECS) is a minimally invasive surgery used to resect GISTs. Herein, we report an extremely rare case of a gastric GIST that grossly vanished during LECS.

CASE PRESENTATION

A 50-year-old Japanese female was referred to our hospital after an abnormality was detected during an esophagogastroduodenoscopy (EGD) at her annual health checkup. Based on EGD, endoscopic ultrasound (EUS), and computer tomography (CT) findings, the patient was diagnosed with a 50-mm submucosal tumor (SMT) with intraluminal growth on the anterior wall of the lesser curvature of the upper body of the stomach. We routinely use LECS to treat the intraluminal growth type of GISTs. During the intraoperative endoscopy, the intraluminal submucosal tumor, which was detected preoperatively, had vanished. A red-white scar was observed in the regressed tumor region. LECS was performed by resecting at a distance away from the scar tissue and closing the gastric wall with intracavitary sutures. In the evaluation from the tumor section view of the original resected specimen, a 22 × 14 × 8 mm lobular neoplasm was observed that was predominantly located in the gastric submucosa to the muscularis propia. Pathological findings confirmed the diagnosis of GIST with intermediate risk indicated by the Fletcher classification. The patient continued postoperative adjuvant chemotherapy with imatinib and no recurrence was detected over 12 months after surgery.

CONCLUSION

LECS was performed on the vanished gastric GIST, providing the best surgical treatment and leading to an accurate diagnosis and optimal postoperative care.

Spontaneous regression of secondary vitreoretinal lymphoma after diagnostic vitrectomy: case report

PURPOSE

Our purpose is to report a patient with secondary intraocular mucosa-associated lymphoid tissue (MALT) who experienced spontaneous regression after diagnostic vitrectomy.

METHODS

We retrospectively reviewed the clinical and imaging features of the case. Multimodal imaging, including fundus photograph, optical coherence tomography, fundus fluorescein angiography and ultrasound scan was presented.

RESULTS

A 71-year-old female presented with a subretinal lesion temporal to macula and scattered multifocal creamy lesions deep to retina in her left eye. Optical coherence tomography of the left eye showed multifocal nodular hyper-reflective signals between the Bruch's membrane and RPE. She had a history of gastric MALT lymphoma. Diagnostic vitrectomy was performed. IL-10 level of aqueous was 187.7pg/ml. Cytology, gene rearrangement and flow cytometry of the vitreous were inconclusive. Systemic evaluation was normal. Secondary vitreoretinal MALT lymphoma was considered. Interestingly, her subretinal lesions regressed gradually without any chemotherapy. And IL-10 level of aqueous declined to 64.3pg/ml.

CONCLUSIONS

Secondary vitreoretinal MALT lymphoma is extremely rare. Spontaneous regression of intraocular lymphoma does occur.

Spontaneous regression of advanced transverse colon cancer with deficient mismatch repair: a case report

BACKGROUND

Spontaneous regression (SR) of cancer occurs in 1 in 60,000-100,000 patients. This phenomenon has been reported in almost all cancer types, most commonly neuroblastoma, renal cell carcinoma, malignant melanoma, and lymphoma/leukemia. However, SR in colorectal cancer (CRC) is extremely rare, particularly in advanced cases. Hence, this report describes a very rare case of spontaneous regression of advanced transverse colon cancer.

CASE PRESENTATION

A 76-year-old female with anemia was diagnosed with a type II well-differentiated adenocarcinoma in the middle transverse colon. Two months later, a second colonoscopy examination was performed for preoperative marking, and it revealed tumor shrinkage and a shift to type 0-IIc morphology. Endoscopic tattooing was then performed, followed by a laparoscopic partial resection of the transverse colon with D3 lymph node dissection. However, the resected specimen contained no tumor, and colonoscopy showed no tumor remnants in the remaining colon. Histopathological examination revealed mucosal regeneration and a mucus nodule in between the submucosal and muscular layers, with no cancer cells detected. Immunohistochemical analysis revealed the loss of MutL homolog 1 (MLH1) and postmeiotic segregation increased 2 (PMS2) expression in the cancer cells of biopsied specimens, suggesting deficient mismatch repair (dMMR). The patient continues to be followed up until 6 years postoperatively, and no recurrence has been observed. In this study, we also reviewed similar reported cases of spontaneous regression of cancer involving dMMR.

CONCLUSION

This study presents a rare case of spontaneous regression of advanced transverse colon cancer wherein dMMR is strongly involved. However, further accumulation of similar cases is needed to elucidate this phenomenon and to develop new treatment strategies for CRC.

A t(4;13)(q21;q14) translocation in B-cell chronic lymphocytic leukemia causing concomitant homozygous DLEU2/miR15a/miR16-1 and heterozygous ARHGAP24 deletions

13q14 deletion is the most recurrent chromosomal aberration reported in B-CLL, having a favorable prognostic significance when occurring as the sole cytogenetic alteration. However, its clinical outcome is also related to the deletion size and number of cells with the del(13)(q14) deletion. In 10% of cases, 13q14 deletion arises following a translocation event with multiple partner chromosomes, whose oncogenic impact has not been investigated so far due to the assumption of a possible role as a passenger mutation. Here, we describe a t(4;13)(q21;q14) translocation occurring in a B-CLL case from the diagnosis to spontaneous regression. FISH and SNP-array analyses revealed a heterozygous deletion at 4q21, leading to the loss of the Rho GTPase Activating Protein 24 (ARHGAP24) tumor suppressor gene, down-regulated in the patient RNA, in addition to the homozygous deletion at 13q14 involving DLEU2/miR15a/miR16-1 genes. Interestingly, targeted Next Generation Sequencing analysis of 54 genes related to B-CLL indicated no additional somatic mutation in the patient, underlining the relevance of this t(4;13)(q21;q14) aberration in the leukemogenic process. In all tested RNA samples, RT-qPCR experiments assessed the downregulation of the PCNA, MKI67, and TOP2A proliferation factor genes, and the BCL2 anti-apoptotic gene as well as the up-regulation of TP53 and CDKN1A tumor suppressors, indicating a low proliferation potential of the cells harboring the aberration. In addition, RNA-seq analyses identified four chimeric transcripts (ATG4B::PTMA, OAZ1::PTMA, ZFP36::PTMA, and PIM3::BRD1), two of which (ATG4B::PTMA and ZFP36::PTMA) failed to be detected at the remission, suggesting a possible transcriptional remodeling during the disease course. Overall, our results indicate a favorable prognostic impact of the described chromosomal aberration, as it arises a permissive molecular landscape to the spontaneous B-CLL regression in the patient, highlighting ARHGAP24 as a potentially relevant concurrent alteration to the 13q14 deletion in delineating B-CLL disease evolution.

Regression rate of high-grade cervical intraepithelial lesions in women younger than 25 years

BACKGROUND/PURPOSE

The incidence and clinical course of high-grade cervical intraepithelial lesions (CIN 2/3) are age dependent. In CIN 3, the recommended treatment is conization, which increases the risk of cervical insufficiency or premature deliveries. But data concerning spontaneous regression of CIN 3 are rare.

METHODS

Between 2007 and 2017, we identified 156 women under the age of 25 with CIN 2 (23%) or CIN 3 (77%), who had a consultation and were treated at the Colposcopy Unit, Hospital of Düsseldorf, Germany. This is a retrospective cohort study. These patients had colposcopical follow-ups every 4-6 months. Moreover, we analyzed various parameters to predict regression of cervical lesions in this age group.

RESULTS

Patients diagnosed with CIN 2 showed regression in 88% (n = 30) and women with CIN 3 had a regression rate of 29% (n = 34). Complete regression was observed in 86.7% of CIN 2 and 47.1% of CIN3. Mean time to regression was 21 M (months) [2-70 M]. 70.9% of the patients were treated by surgery (LEEP) after persistence or progression. We identified several predictors for regression of CIN 2/3 in young women: the regression rate of CIN2 is significantly higher than CIN 3 (p < 0.001). Clearance of HPV infections had significantly higher rates of regression compared to persisting HPV infections (p < 0.001). HPV-vaccinated women showed significantly higher regression rates (p = 0.009).

CONCLUSIONS

These data show that an expectative close follow-up in women with CIN 3 younger than 25 is possible with regression rates of 29% also for CIN 3. Especially in women who were HPV vaccinated and those who cleared their HPV infection. A frequent colposcopical follow-up every 3-4 months is important for CIN 3 and every 6 months for CIN 2.

Spontaneous regression in solid pseudopapillary neoplasm of pancreas

A solid pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm that mainly occurs in young women. We herein report the case of spontaneous regression in SPN of the pancreas. A 48-years-old female was found to have a mass in the head of the pancreas on examination for her back pain and referred to our hospital in 20XX. Laboratory data showed no abnormalities in serum levels of pancreatic enzymes and tumor markers. A contrast CT scan of upper abdomen showed a slightly enhanced lesion (23 × 19 mm in diameter) without cystic component or fibrous capsule in the head of the pancreas. An MRI scan showed the mass as low-intensity in T1-WI and high-intensity in T2-WI. She admitted to our hospital for further examination of a pancreatic mass by EUS-FNA in 20XX + 4. EUS showed a slightly hypoechoic mass (30 × 19 mm in diameter) compared with the neighboring normal pancreas. Tumor margin was relatively clear and the internal echo image was homogenous. Histological findings revealed a solid and pseudopapillary proliferation of eosinophilic polygonal cells with oval nuclei. The tumor cells were positive for vimentin and CD10 in the cytoplasm and β-catenin in the nuclei, which led to the diagnosis of SPN. We recommended this patient to undergo surgical resection, however, the patient chose follow-up examinations. Follow-up study after 1 year using MRI scan showed spontaneous regression, which was coincided with her menopause. These findings suggest that the natural regression of SPN may occur and female sex hormone changes may regulate the growth of SPN.

Epithelioid Hemangioendothelioma of the Liver Showing Spontaneous Complete Regression after the Cessation of Methotrexate Intake

A 71-year-old man with slight fever and dull abdominal pain was referred to our hospital. He had been receiving methotrexate (MTX) to treat his rheumatoid arthritis for more than 6 years but stopped taking MTX after admission due to the rapid aggravation of his liver function. Computed tomography (CT) showed multiple liver lesions with late enhancement, highly suggesting them to be cholangiocarcinomas. Tumor marker levels were normal except for a slightly elevated PIVKA-II level, i.e., 45 mAU/mL (range 0-40 mAU/mL). We did a biopsy to the largest lesion and endoscopic biliary drainage to make a definitive diagnosis of the hepatic lesions and treat jaundice, respectively. Pathological study showed round, polygonal, and spindle-shaped epithelial atypical cells growing in a sarcomatoid fashion. Atypical cells were positive for CD31, CD34, vimentin, and TFE3, and some of them had intracellular vacuoles, leading to the diagnosis of epithelioid hemangioendothelioma (EHE) of the liver. The patient got well 4 weeks after the endoscopic biliary drainage. CTs showed marked regression of the EHE lesions 3 months after biliary drainage and complete regression in 12 months. The patient further developed Hodgkin lymphoma in the para-aortic lymph nodes 23 months after the biliary drainage and is now under chemotherapy for the malignant lymphoma. We, however, have not detected any EHE lesions in the liver or distant organs for at least 16 months after the confirmation of complete regression of the EHE lesions. Oncologists should note the spontaneous regression of the EHE and investigate the correlation between MTX cessation and EHE regression.

Rapid Dissemination followed by Spontaneous Regression of Metastatic Hepatocellular Carcinoma after Liver Radiofrequency Thermal Ablation: A Case Report with Correlative Immune Assay

Rapid intrahepatic and distant metastasis of hepatocellular carcinoma (HCC) after locoregional treatment for early stage tumor is very rare. Descriptions of spontaneous regression of HCC exist in case reports, but its true mechanism is unclear. Here, we describe a case of rapid dissemination with lung metastasis shortly after localized RFA treatment of HCC liver lesions, followed by spontaneous, sustained regression of those lung lesions. We also show the detection of cytotoxic T lymphocytes (CTLs) specific to hepatitis B antigens by immune assay in this patient. We propose immune-related destruction as the basis for spontaneous regression.

Spontaneous resolution of syringomyelia following pregnancy and parturition in a patient with type I chiari malformation: A case and systematic review

BACKGROUND

Spontaneous resolution of syringomyelia has rarely been reported in the literature. Rarer still are cases wherein this process is associated with pregnancy and parturition. We review theories on syringomyelia development and spontaneous resolution to better understand the role pregnancy and parturition may play in both processes.

METHODS

We present a 30-year-old female with MRI-confirmed spontaneous syrinx regression following caesarean delivery of a full-term pregnancy. We additionally review the literature to identify previously reported cases of spontaneous syrinx regression both independent of and associated with pregnancy.

RESULTS

Including the present case, 39 cases describing spontaneous regression of syringomyelia have been reported in the literature, of which only four are associated with pregnancy and parturition. 75% of all reported cases were associated with type I Chiari malformation, though several disorders of the craniocervical junction and spinal canal were implicated. Complete syrinx regression was achieved in 33.3% of cases and 5% of cases described recurrence of syringomyelia following the spontaneous resolution.

CONCLUSION

Syringomyelia likely develops due to disturbance of the physiologic flow of cerebrospinal fluid around the craniocervical junction and the obex. Several mechanisms including fissuring of the spinal cord parenchyma and reduction of subarachnoid scarring are likely involved in this process. In the setting of pregnancy, additional mechanisms surrounding the increased intraabdominal forces imparted by a growing fetus, Valsalva-like strain experienced during labor, and hemodynamic changes that occur to accommodate gestation are likely implicated. Nevertheless, patients should continue to be monitored periodically for syrinx recurrence.

Secondary vitreoretinal lymphoma with spontaneous regression

Purpose

To report a patient with vitreoretinal lymphoma (VRL) secondary to systemic diffuse large B-cell lymphoma, who had two episodes of spontaneous regression.

Observations

An 80-year-old Nicaraguan male with a history of treated systemic diffuse large B-cell lymphoma presented with decreased vision in his right eye over one year. The patient was found to have subretinal lesions and moderate vitreous opacities in his right eye. Cytological analysis of vitreous confirmed B-cell lymphoma. Following his systemic work-up, spontaneous clinical improvement was noted. There were no vitreoretinal or systemic lymphoma recurrences during one year of follow-up until the patient had new onset decreased vision in the left eye. He was presumed to have a recurrence of VRL supported by optical coherence tomography findings. Repeat systemic workup was negative for reoccurrence and the ocular lesions resolved spontaneously over 4 weeks.

Conclusions

Spontaneous regression of intraocular lymphoma can rarely occur. Multimodal imaging has an essential role in diagnosing and monitoring recurrence of this disease.

Spontaneous regression of a thrombosed cerebral arteriovenous malformation in a patient with a prothrombotic state associated with multiple myeloma: A case report and literature review

Background

Cerebral arteriovenous malformations (AVMs) are pathologic communications between veins and arteries of the brain vasculature. Its spontaneous regression is rare, and many factors have been described in the effort to explain this phenomenon, including a hypercoagulable state.

Case Description

We present the case of a spontaneous unruptured AVM regression in a patient where thrombosis of the malformation was found, probably due to a prothrombotic state associated with multiple myeloma (MM).

Conclusion

We aim to contribute to the study of this rare phenomenon, presenting the relationship between a hypercoagulable state caused by MM and the spontaneous AVM regression that has not been previously reported.

Spontaneous regression of multiple intracranial capillary hemangiomas in a newborn-long-term follow-up and literature review

BACKGROUND

Intracranial capillary hemangiomas (ICHs) have a natural history and behavior that is very different from intracranial cavernous malformations. The literature is not consistent as to the best management strategy for ICHs.

CASE DESCRIPTION

Our patient is a 40-day-old male infant who presented with progressive increase in head circumference and multiple cutaneous capillary and ICHs. Obstructive hydrocephalus necessitated urgent cerebrospinal fluid (CSF) diversion, but no other surgical intervention was pursued due to the high risk-to-benefit ratio. All intracranial lesions spontaneously regressed by 11 years of age, albeit at a slower speed than the cutaneous lesions, with no functional or cognitive sequelae. We conducted a comprehensive literature review and provided a summary of all reported ICH cases.

CONCLUSION

Asymptomatic patients with ICHs are best approached with close follow-up and serial imaging studies as the potential for spontaneous regression is relatively high. Patients with isolated lesions or unclear diagnoses may benefit from a stereotactic biopsy, and surgical resection should be reserved for symptomatic lesions only.

Spontaneous regression following endobronchial ultrasound-guided transbronchial needle aspiration in lung cancer patients

Spontaneous regression (SR) is defined as a complete or partial, temporary or permanent disappearance of a tumor without anticancer treatment, which potentially develops after surgery or biopsy for primary and metastatic tumors despite unknown incidence rate. Here, we report the incidence rate of SR after endobronchial ultrasound-guided transbronchial nodal needle aspiration (EBUS-TBNA) in lung cancer patients. Among 96 patients evaluable with chest CT before and after EBUS-TBNA, SR was found in three patients (3.1%). With regards to patient characteristics, two patients had small cell lung cancer (SCLC), and one patient had adenocarcinoma. All patients had stage 3 disease with a bulky N2 stage and a history of smoking. Two patients also had interstitial lung disease. Notably, SR was observed not only at the biopsied site, but also at the non-biopsied site. Our results indicate that SR can develop following EBUS-TBNA in a substantial proportion of lung cancer patients.

A scoping review on the "burned out" or "burnt out" testicular cancer: When a rare phenomenon deserves more attention

The "burned out" or "burnt out" testicular cancer (BTC) indicates the spontaneous and complete regression of a testicular germ cell tumor in the presence of distant metastases at the diagnosis. As this condition was never reviewed systematically, a scoping review was conducted to scrutinize the available literature on clinical and histological features of BTC patients. Medline was searched from inception to 19 April 2020. A virtual cohort of 68 BTC patients was generated. Our findings highlighted some inconsistencies: BTC was diagnosed in 5,9% of patients not showing distant metastases and in 2,9% of patients who did not undergo an orchiectomy. Besides, evidence of residual tumor was found in 22,7% of testis specimens, recognized as seminoma in 40% of cases. The emerged inconsistencies may derive from the lack of an unequivocal definition of BTC. Larger collaborative studies are needed to define the best diagnostic workup and treatment for BTC patients.

Predictive factors of spontaneously regressed uterine endometrial polyps during the waiting period before hysteroscopic polypectomy

BACKGROUND

The presence of uterine endometrial polyps is associated with not only abnormal uterine bleeding but also infertility, so the use of hysteroscopic polypectomy has been increasing. This operation is considered to increase cost-effectiveness when performed prior to infertility treatments. However, there are typical problems to consider, including the possibility of spontaneous regression of the polyp and the duration of complete endometrial wound healing after surgery. Meaningless interventions must be avoided, when possible. Therefore, data acquisition and analysis of various findings obtained from surgery have become important for improving treatment procedures and patient selection. To estimate the spontaneous regression rates and contributions of multiple factors to uterine endometrial polyps during the waiting period (approximately 2-3 months) before hysteroscopic polypectomy, we performed a multivariate analysis of data from the records in our hospital.

METHODS

The medical records of 450 cases from September 2014 to April 2021 in our hospital were retrospectively reviewed under the approval of our Institutional Review Board. We included all cases of hysteroscopic polypectomy with postoperative pathological diagnosis. We defined cases as having a "spontaneously regressed polyp" when the target polyp was not detected by postoperative pathological examination. We extracted data on the following ten factors: "Advanced age" (≥ 42 years), "Small polyp" (< 10 mm), "High body mass index" (≥ 25 kg/m2), "Nulliparity," "Single polyp," "Infertility," "Hypermenorrhea," "Abnormal bleeding," "No symptom," and "Hormonal drug use." We also classified cases into five groups according to the size of the polyp (≤ 4.9 mm, 5.0-9.9 mm, 10.0-14.9 mm, 15.0-19.9 mm, and ≥ 20.0 mm) and determined the frequency of spontaneously regressed polyp in each group.

RESULTS

After exclusion of cases with insufficient data or other diseases, such as submucosal leiomyoma, 424 cases were analyzed. Among them, 28 spontaneously regressed polyps were identified, and the highest frequency of spontaneously regressed polyp was detected among the cases with polyps measuring 5.0-9.9 mm (16.4%). On multivariate analysis of the ten factors, "Small polyp" and "Hormonal drug use" were found to significantly impact the frequency of spontaneously regressed polyp.

CONCLUSIONS

On the basis of the factors identified in this analysis, the indications for observation or medical therapy adapted to small polyps might be expanded.

Possible spontaneous regression of hepatocellular carcinoma with unique histopathological features confirmed by surgical resection: a case report

Background

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare event, and its clinicopathological features and underlying mechanism are not fully understood.

Case presentation

An 84-year-old female with hepatitis C virus infection and diabetes mellitus was referred to our hospital for further examination. Abdominal ultrasonography showed a 3.4-cm solid tumor with a heterogeneous irregular center and no fibrous capsule in liver segment 8 (S8). An enhanced computed tomography (CT) scan revealed a tumor in S8 with heterogeneous enhancement in the arterial phase and washed out insufficiently in the portal and equilibrium phase. The enhanced pattern on magnetic resonance imaging was similar to that of CT. Although the imaging findings were not typical for HCC, liver resection (S8) was performed with HCC as the most probable diagnosis. Histopathological examination of the resected specimen showed that the tumor was well to moderately differentiated HCC with unique features. Approximately half of the tumor was composed of well-differentiated HCC that was focally accompanied by dense lymphocyte infiltration. The other half of the tumor was fibrotic tissue that resembled an inflammatory pseudotumor. Several foci of moderately differentiated HCC were scattered within the tumor with a nodule-in-nodule appearance, and the foci totally showed coagulative necrosis. On immunostaining, lymphocytes in the tumor stroma were positive for CD8 and programmed death 1. The expression of programmed death-ligand 1 was observed in carcinoma cells and macrophages specifically within the lymphocyte-rich area of HCC.

Conclusions

We consider this case representative of spontaneous regression of HCC, and the immune response against HCC might contribute to tumor regression, leading to complex histopathological appearances. This case may provide insight into the mechanism of spontaneous regression of HCC.

The spontaneous remission of cancer: Current insights and therapeutic significance

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Spontaneous remission (SR) of cancer is a rare but well-documented phenomenon.

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Mechanisms of SR are described in detail.

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Knowing the intricacies of SR would help in devising novel treatment strategies.

Many diseases heal spontaneously. The common cold, for example, remedies itself within a few days in people with an uncompromised immune system. If a disease with a poor prognosis heals in the absence of a targeted therapeutic, many even call it a miracle cure. Such is the case with the spontaneous regression (SR) of malignant neoplasms, a rare but well-documented phenomenon that finds its first mention in the Ebers Papyrus of 1550 BCE. Given the challenges associated with current cancer treatment modalities such as rapidly evolving drug resistance mechanisms, dose-limiting side effects, and a failure to completely eliminate cancer cells, knowledge of how a tumour heals itself would be immensely helpful in developing more effective therapeutic modalities. Although the intricate mechanisms of SR have yet to be fully elucidated, it has been shown that infection-mediated immune system activation, biopsy procedures, and disruptions of the tumour microenvironment play pivotal roles in the self-healing of many tumours. Bacterial and viral infections are especially well-documented in instances of SR. Insights from these findings are paving the way for novel therapeutic strategies. Inspired by bacteria-mediated SR, Bacillus Calmette-Guérin (BCG) has been used as an approved treatment option for non-muscle-invasive bladder cancer (NMIBC). Similarly, Talimogene laherparepvec (T-VEC), the first engineered oncolytic herpes simplex virus (HSV), has been approved by the United States Food and Drug Administration for the treatment of some forms of advanced melanoma. Here we describe the current understanding of SR, explore its therapeutic significance, and offer perspectives on its future.

Long-term spontaneous regression of Stage IV diffuse large B-cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is an aggressive disorder accounting for >30% of all lymphomas. Its prognosis is poor due to a high relapse rate. Spontaneous regression (SR) in DLBCL is rare, with only a few reported cases. Moreover, almost all of these were low-grade lymphomas with an average SR duration of 13 mo. As the cause of SR is unknown, there are many theories such as trauma, infection, medication, and an antitumor immune response. We present a patient with progressive DLBCL who demonstrated SR for >42 mo. Although treatment for lymphoma usually starts soon after diagnosis, insights into SR of lymphomas may lead to new treatment strategies.

Spontaneous regression of lung metastases after transarterial chemoembolization for hepatocellular carcinoma

Spontaneous regressions of primary and/or metastatic lesions have been rarely reported in hepatocellular carcinoma (HCC). Herein, we report the case of a 71-year-old man with HCC, focusing on shape changes of lung metastases over time. Lung metastasis of HCC was histologically diagnosed by percutaneous computed tomography (CT)-guided needle biopsy after the treatment of primary HCC lesion. Lung lesions had been observed on enhanced contrast computed tomography for >3 years without any local or systemic treatment for them. During this period, treatments including surgical procedure for relapsed bladder cancer and transarterial chemoembolization for HCC were performed. Metastatic lung lesions immediately regressed after these treatments. Therefore, accumulation of such cases may help elucidate spontaneous regression mechanisms in primary HCC or its lung metastases.

Spontaneous regression of herniated cervical disc: A case report and literature review

Background

We have reviewed 75 cases plus our own single instance of spontaneous regression of herniated cervical discs.

Methods

We searched PubMed and EMBASE databases (until September 2020) utilizing the following keywords; "spontaneous regression," "herniated cervical disc," and "Magnetic Resonance Imaging (MRI) studies."

Results

In the literature, we found 75 cases of herniated cervical discs which spontaneously regressed; to this, we added our case. Patients averaged 40.95 years of age. Discs were paracentral or foraminal in 84% of the cases, with most occurring at the C5-C6 (51%) and C6-C7 (36%) levels. Symptoms included neck pain/radiculopathy (91%) or myelopathy (9%). The average interval between initial presentation and spontaneous regression of herniated discs on MRI was 9.15 months. Interestingly, on MRI, extruded/sequestrated discs were more likely to undergo spontaneous regression versus protruding discs.

Conclusion

Successive MRI studies documented the spontaneous regression of herniated cervical discs over an average of 9.15 months. Although this may prompt greater consideration for conservative treatment in younger patients without neurologic deficits, those with deficits should be considered for surgery.

Preoperative Cyst Formation as a Predictive Feature of Spontaneous Regression of Retro-Odontoid Pseudotumor After Posterior Fusion

OBJECTIVE

Although the spontaneous regression of pseudotumors after posterior fusion has been reported, the predictive factors remain unclear. We examined the radiological features that predict for the regression of retro-odontoid pseudotumors after posterior fusion, with a specific focus on cyst formation.

METHODS

We included 28 patients with a diagnosis of retro-odontoid pseudotumor using preoperative magnetic resonance imaging. The radiographic parameters and pseudotumor thickness were measured pre- and postoperatively. The regression rate for each pseudotumor was calculated. The presence of a cyst around the retro-odontoid pseudotumor was investigated. If present, the cyst thickness was measured. To elucidate the predictors for the postoperative regression of pseudotumors, the patients were divided into 2 cohorts: the regression group with a regression rate >40% and the no-regression group with a regression rate of <40%. Multivariate logistic regression analysis, including the demographic data and preoperative radiographic parameters as independent variables, was performed.

RESULTS

The mean pseudotumor size had decreased significantly from 8.8 ± 3.6 mm preoperatively to 5.3 ± 2.0 mm postoperatively (P < 0.0001). The mean regression rate was 35.9% during a magnetic resonance imaging follow-up period of 8.6 months (range, 6-12 months). Cystic lesions were noted in 10 patients (35.7%) preoperatively. The mean cyst size was 4.7 ± 1.9 mm. All cysts were located dorsal to the pseudotumors and were involved at the maximum spinal compression levels. Nevertheless, all the cysts had disappeared postoperatively. Multivariate logistic regression analysis revealed that the pseudotumor regression group had had a significantly greater proportion of cysts (57.1% vs. 14.3%; odds ratio, 11.7; P = 0.013).

CONCLUSIONS

The presence of cystic lesions protruding from retro-odontoid pseudotumors might serve as a predictive factor for the spontaneous regression of pseudotumors after posterior fusion.

Spontaneous Regression of Palmar Warts after Suffering from Diffuse Contact Dermatitis against Alkyl Bromide

Contact immunotherapy with several sensitizing chemicals such as diphenylcyclopropenone (DPCP) or squaric acid dibutyl ester (SADBE) have been used for the treatment of recalcitrant or multiple warts. Here, we report a case of multiple verrucae vulgaris (VV) on the palm which spontaneously resolved after the development of systemic contact dermatitis against alkyl bromide. We considered that our case accidentally mimics contact immunotherapy against multiple VV. VV sometimes regress spontaneously, which may be triggered by accidental contact dermatitis, as shown in our case.

A boy with a congenital cerebellar mass

PURPOSE

Tumorigenesis of medulloblastoma is believed to be associated with granule cell progenitor neurogenesis of the cerebellum. Nevertheless, congenital medulloblastomas are rarely found. Here, we report a case of congenital medulloblastoma that showed spontaneous albeit transient regression.

METHODS

A one-month-old baby presented with abnormal antenatal and postnatal imaging findings. Upon ultrasonography at 26 weeks of gestational age, Dandy-Walker malformation with vermian hypoplasia and cystic change was suspected. Brain MRI at 1 week after birth revealed gadolinium-enhancing lesions in the cerebellum with apparent infiltrative features along the cerebellar folia accompanied by three independent cysts in the upper and inferolateral sides of the lesion. Serial MRIs taken up to 5 months of age showed a decrease in the size and extent of enhancing solid portions. The baby did not show any abnormal signs or developmental delay. MRI at the age of 7 months showed enlargement of the lesion, and surgery was performed.

RESULTS

The lesion was diagnosed as medulloblastoma with histologically extensive nodularity (MBEN), genetically SHH-activated and TP53-wildtype.

CONCLUSION

This case provides an unusual chance of observing an early phase of medulloblastoma development and raises a suspicion that medulloblastoma may initiate itself very early in cerebellar organogenesis and progress later at a certain time of postnatal development.

Clinical features and treatment strategies for post-transplant and iatrogenic immunodeficiency-associated lymphoproliferative disorders

A specific category termed immunodeficiency-associated lymphoproliferative disorders (LPD) exists in the 2016 revised WHO classification concerning lymphoid neoplasms. This category is defined by etiology and includes LPD developing in association with organ transplantation or immunosuppressive/immunomodulatory agents including methotrexate. The functional mechanism is chiefly explained by the autonomous proliferation of Epstein-Barr virus (EBV)-infected lymphocytes induced by host-immune suppression. This category ranges from reactive lymphocyte hyperplasia to monomorphic lymphoma. Its clinical behavior varies depending on host immunity and pathological features; pathological confirmation by biopsy is thus important for deciding treatment strategies. Owing to the spontaneous regression observed in some patients, uniform chemotherapy is not recommended. The main initial treatment options include the reduction in immunosuppressive drugs, immunotherapy with the anti-CD20 antibody rituximab, chemotherapy, or a combination of these. Other novel treatments such as adoptive immunotherapy with EBV-specific cytotoxic T cells, could be an alternative for relapsed/refractory diseases in clinical trials.

Spontaneously regressed granulomatosis with polyangiitis: A case report

A 71-year-old woman presented with chest pain, cough, and back pain. A chest roentgenogram showed multiple nodular shadows in both lungs. She was diagnosed with granulomatosis with polyangiitis (GPA). The multiple nodular shadows in both lungs regressed spontaneously in a few months. There are few reports of spontaneous regression of GPA, and the underlying mechanism is unclear. Neutrophil extracellular traps (NETs) have been recently shown to be involved in GPA. NETs may also be related to the natural regression of GPA.

Spontaneous regression of breast cancer with immune response: a case report

Background

Spontaneous regression (SR) is a rare phenomenon in which a cancer disappears or remits without treatment. We report a case of breast cancer that showed spontaneous tumor regression in the surgical specimen after core needle biopsy.

Case presentation

A 59-year-old woman came to our hospital complaining of a painful lump in the right breast. In the upper-outer quadrant of the right breast, a tumor with an unclear boundary, 30 mm in diameter, was palpable. In pathological findings from needle biopsy, the tumor was diagnosed as solid-type invasive ductal breast carcinoma. Partial coagulation necrosis was generated in estrogen receptor-negative, HER2-negative, and AE1/AE3-positive ductal carcinoma without infiltration of lymphocytes. Surgery for right breast cancer was then performed. Histological examination of the surgical specimen revealed the tumor was invasive ductal carcinoma with lymphocyte infiltration, coagulation necrosis, and fibrous tissue with hemosiderin. The tumor formed a solid nest, 3 mm in diameter, suggesting the possibility of SR.

Conclusions

Immune responses, infection, hormones, surgical stress, and ischemia have been reported as mechanisms of SR. The findings in this case strongly suggest that SR of breast cancer is associated with anti-tumor immune responses.

Clinical and Radiological Follow-Up Results of Patients with Sequestered Lumbar Disc Herniation: A Prospective Cohort Study

PURPOSE

The aim of the study was to assess radiological changes and clinical outcomes of patients with sequestered lumbar disc herniation (LDH) and evaluate the relationship between them.

METHODS

Patients diagnosed with sequestered LDH were followed up in 2 groups: operated (within the 1st month after diagnosis) and nonoperated. Visual analog scale (VAS) and Oswestry Disability Index (ODI) scores at baseline (V1) and 1st (V2), 3rd (V3), and 6th (V4) month visits were used for clinical evaluation. Radiological evaluation was performed by measuring the sequestered LDH level and herniation volume using magnetic resonance imaging (MRI) at V1 and V4. After the second MRI, patients in the nonoperated group were divided into 3 groups: nonregression (n = 6), partial regression (n = 22), and complete resolution (n = 27); patients were analyzed in 4 groups including the ones in the operated (n = 25) group.

RESULTS

Significant improvements were observed in VAS and ODI scores at V2 and V3 in all groups (p = 0.000) and at V4 in partial regression and complete resolution groups (p = 0.000). VAS and ODI score improvements at V2 and V3 were significantly higher in the operated group than in other groups (p = 0.000). At V4, there were no significant differences in VAS and ODI scores (p > 0.05) between the operated group and partial regression and complete resolution groups.

CONCLUSION

Spontaneous regression was observed in the 6th month post-MRI in most of the nonoperated sequestered LDH patients with conservative treatment. Improvements in pain and disability scores were higher among the operated patients at the early stage, whereas they were not significantly different compared to patients with spontaneous regression at the 6th month.

Spontaneous regression of lung metastases in hepatocellular carcinoma: A case report

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The prognosis of patients with advanced HCC remains poor even if appropriate treatments are administered.

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Spontaneous regression of lung metastases of hepatocellular is a rare condition.

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We discuss the mechanism for spontaneous regression of multiple pulmonary recurrences of hepatocellular carcinoma.

Introduction

Spontaneous regression of hepatocellular carcinoma (HCC) is a rare condition. However, although there have been multiple reports of spontaneous regression, the definitive pathogenic mechanism of this phenomenon is still unclear.

Case presentation

We encountered a case of a 78-year-old man who was undergoing dialysis for end-stage kidney disease with hepatitis C virus-associated chronic hepatitis presenting with HCC. The patient had previously undergone right lobectomy of the liver, but the cancer recurred with multiple lung metastases after 5 months. Approximately 13 months after the initial diagnosis of recurrence, the lung metastases decreased in size and eventually resolved without any anticancer therapy. The patient remains alive for over 41 months after recurrence.

Discussion

Based on our case and literature, Hypoxia with hypotension due to hemodialysis can reduce the blood and oxygen supply of the body, which may lead to the spontaneous regression of the metastatic tumors.

Conclusion

We herein reported a case of spontaneous regression of HCC undergoing dialysis.

Temporary spontaneous regression of male breast cancer: a case report

Background

Spontaneous regression (SR) of a malignant tumor is the partial or complete disappearance of primary or metastatic tumor tissue in the absence of treatment, which can be temporary or permanent. Here, we report an extremely rare case of male breast cancer that exhibited temporary SR followed by reappearance 8 months after tumor disappearance.

Case presentation

A 70-year-old man presented at our hospital with a primary complaint of pain and a lump in his left breast. Ultrasonography revealed a hypoechoic lesion measuring 12 mm × 10 mm × 8 mm. Fine-needle aspiration cytology revealed numerous necrotic and degenerated cells and few sheet-like clusters of atypical ductal epithelial cells. The atypical cells had mildly enlarged nuclei with nucleoli, were focally overlapped and formed tubular patterns. The cytological diagnosis indicated a suspicion of malignancy. Core needle biopsy (CNB) revealed necrotic and degenerated cells with microcalcification. The pathological diagnosis was indeterminate because there was no area of viable atypical cells. An excisional biopsy of the left breast lesion was scheduled one month later. However, it was difficult to detect the tumor during physical examination and ultrasonography performed 1 month after the patient’s first visit. The operation was canceled, and the patient received follow-up observation. After 8 months of follow-up, ultrasonography and computed tomography (CT) revealed reappearance of a 0.6-cm-diameter breast tumor in the same place. CNB was performed again and revealed invasive ductal carcinoma. A total mastectomy with sentinel lymph node biopsy was performed 13 months after the first tumor disappeared. Histopathological examination revealed invasive cribriform carcinoma without sentinel lymph node metastasis. The patient did not have any complications, and adjuvant therapy with tamoxifen was started. The patient was alive without recurrence 7 months after surgery.

Conclusions

Temporary SR followed by tumor reappearance can occur in breast cancer cases, and it is important to follow patients even if their breast tumor has seemingly disappeared. When breast tumors disappear without treatment, clinicians must be aware of the possibility of SR of cancer and should follow the patient for early detection of tumor reappearance.

Spontaneous Regression of Delayed Pulmonary and Mediastinal Metastases from Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is often metastatic at diagnosis. Conventional therapies such as chemotherapy, radiotherapy, and hormonal therapy have generally proven ineffective in the treatment of RCC. The abscopal effect, specifically, the ability of localized radiation to trigger systemic antitumor effects, has been reported to lead to regression of non-irradiated distant tumor lesions. Herein, we report 3 patients with non-metastatic clear cell RCC (CCRCC) who underwent a nephrectomy and experienced metachronous pulmonary/mediastinal metastases confirmed as CCRCC. No patients underwent radiation post-nephrectomy or pulmonary metastasectomy. The mean duration was 7.24 weeks from the last negative chest CT prior to the nephrectomy and 96.2 weeks post-nephrectomy. All patients achieved durable complete response by RECIST criteria, with a mean follow-up duration of 115 months. Our case series represents the largest in the literature of patients who underwent a nephrectomy for CCRCC with no pre-existing pulmonary/mediastinal metastatic disease confirmed by chest CT, did not undergo radiotherapy, and developed significantly delayed CCRCC pulmonary/mediastinal metastases. We highlight the spontaneous regression of delayed metastatic disease and the role of immune responses in curtailing the growth of pulmonary metastasis in CCRCC.

Spontaneous regression of a pulmonary arteriovenous malformation during endocrine therapy for breast cancer

A 52-year-old woman with right-sided breast cancer was diagnosed with a left pulmonary arteriovenous malformation (PAVM) by computed tomography (CT). Percutaneous embolization of the PAVM after treatment of the breast cancer was scheduled to prevent a paradoxical embolic event. She underwent lumpectomy, followed by systemic chemotherapy in combination with tangential field radiotherapy. Subsequently, she received endocrine therapy with tamoxifen, anastrozole, and exemestane, sequentially. There was no change in the PAVM on CT performed during the administration of anastrozole. Subsequently, CT performed five months after switching to exemestane showed obviously decreased size of the affected vessels, and the sac had almost disappeared. To the best of our knowledge, this is the first case report to describe the spontaneous regression of a PAVM during endocrine therapy for breast cancer.

Histopathological variation in the demyelinating sentinel lesion of primary central nervous system lymphoma

Background:

Primary central nervous system lymphoma (PCNSL) is one of the least common malignant brain tumors. It is usually diagnosed initially as diffuse large B cell lymphoma (DLBCL). In rare cases, however, a demyelinating lesion referred to as a “sentinel lesion” precedes the actual diagnosis, which usually depicts two distinct patterns of inflammatory cells during histological analysis. This case report describes a unique histological finding and describes the recognized variations in sentinel lesion histopathology.

Case Description:

A 78-year-old female patient was found to have multiple white matter lesions of various degrees of enhancement on post-contrast T1-weighted magnetic resonance imaging. A stereotactic biopsy of a heterogeneous lesion in the left occipital lobe was performed, which revealed demyelination along with lymphocytic infiltration, reactive astrocytosis, abundant T cells, and foamy macrophages. There was no evidence of monoclonality, rapid regression of all lesions occurred, and the patient was thus treated for tumefactive demyelination. Three months later, all of the residual lesions had enlarged and were homogeneously enhancing. An endoscopic-guided biopsy of the right periventricular lesion showed diffuse atypical lymphoid cells.

Conclusion:

The sentinel lesion of PCNSL expresses a variable histological pattern of inflammatory cells. This case demonstrates a unique and rare picture of mixed perivascular and parenchymal infiltration of inflammatory cells, highlighting the importance of repeated biopsies and/or radiological examinations to obtain an accurate diagnosis.

Spontaneous regression of ALK fusion protein-positive non-small cell lung carcinoma: a case report and review of the literature

BACKGROUND

ALK-rearrangement is observed in < 5% non-small cell lung cancer (NSCLC) cases and prior to the advent of oral tyrosine kinase inhibitors, the natural history of oncogenic NSCLC was typically poor. Literature relating to regression of treatment-naïve NSCLC is limited, and regression without treatment has not been noted in the ALK-rearranged sub-population.

CASE PRESENTATION

A 76 year old 'never smoker' female with an ALK-rearranged left upper lobe T2 N0 NSCLC experienced a stroke following elective DC cardioversion for new atrial fibrillation. Following a good recovery, updated imaging demonstrated complete regression of the left upper lobe lesion and a reduction of the previously documented mediastinal lymph node. Remaining atelectasis was non-avid on repeat PET-CT imaging, 8 months from the baseline PET-CT. When the patient developed new symptoms 6 months later a further PET-CT demonstrated FDG-avid local recurrence. She completed 55 Gy in 20 fractions but at 18 months post-radiotherapy there was radiological progression in the lungs with new pulmonary metastases and effusion and new bone metastases. Owing to poor performance status, she was not considered fit for targeted therapy and died 5 months later.

CONCLUSION

All reported cases of spontaneous regression in lung cancer have been collated within. Documented precipitants of spontaneous regression across tumour types include biopsy and immune reconstitution; stroke has not been reported previously. The favourable response achieved with radical radiotherapy alone in this unusual case of indolent oncogenic NSCLC reinforces the applicability of radiotherapy in locally advanced ALK-rearranged tumours, in cases not behaving aggressively. As a common embolic event affecting the neurological and pulmonary vasculature is less likely, an immune-mediated mechanism may underpin the phenomenon described in this patient, implying that hitherto unharnessed principles of immuno-oncology may have relevance in oncogenic NSCLC. Alternatively, high electrical voltage applied percutaneously adjacent to the tumour during cardioversion in this patient may have induced local tumour cell lethality.

Spontaneous Regression Followed by Rupture of an Untreated Brain Arteriovenous Malformation

BACKGROUND

Brain arteriovenous malformations (AVMs) are dynamic lesions. Unlike the recruitment of additional vessels and the growth of the nidus over time, which are well reported in the literature, spontaneous regression is much less frequent. Only a handful of cases reporting recanalization of spontaneously regressed AVMs have been published. AVMs that undergo spontaneous regression typically share structural and historical features, including previous hemorrhage, a small nidus, superficial venous drainage, and a single draining vein. Structural features and hemodynamic changes may predispose brain AVMs to spontaneous regression, and angiogenic processes are hypothesized to contribute to recanalization and hemorrhage.

CASE DESCRIPTION

We present the case of a 37-year-old female who had been diagnosed 12 years ago with an unruptured Spetzler-Martin grade 3 AVM in the left medial occipital lobe after a history of progressively worsening migraines. The AVM was monitored for 1 year, but the patient was lost to follow-up until 11 years later, when the AVM nidus was found to be significantly smaller in size. One month later, the patient presented with acute intraparenchymal hemorrhage due to rupture of the AVM, which was then surgically resected.

CONCLUSIONS

Our case is the second reported case of rupture of a spontaneously regressed AVM and the first reported case of this outcome with no history of previous hemorrhage. Close monitoring of brain AVMs may be warranted for longer periods of time than previously recommended.

A curious case of vanishing pituitary adenoma

Pituitary macroadenoma is the most common suprasellar lesion in adults. If symptomatic, it is managed surgically via transsphenoidal resection. Patients commonly present with headache and visual disturbances. If the tumour is large enough, it may have mass effect and patient may present with symptoms of elevated intracranial pressure like severe headache, nausea and vomiting. Functional adenomas may cause endocrine dysfunction. Here, we present a case of pituitary macroadenoma in a young adult female who presented with headache. Initial CT and MRI revealed a pituitary macroadenoma. However, repeat imaging done preoperatively showed complete regression of the lesion and a normal appearing pituitary gland.

Spontaneous regression of advanced transverse colon cancer with remaining lymph node metastasis

BACKGROUND

The observation of spontaneous regression (SR) has been well documented for many cancer types, including renal cell carcinoma, non-Hodgkin's lymphoma, leukemia, neuroblastoma, and malignant melanoma. However, the SR frequency in colorectal cancer is very rare. Therefore, the accumulation of SR colorectal cancer cases might contribute to find the regression mechanism.

CASE PRESENTATION

A 67-year-old woman received colonoscopy due to being positive for fecal occult blood testing and was diagnosed as having a transverse colon cancer at a local hospital. She was admitted to our institution for surgical treatment of the colon cancer. The colonoscopy revealed a type 2 tumor of 13 mm in diameter at the hepatic flexure of the transverse colon. The enhanced computed tomography (CT) showed an enlarged lymph node in the intermediate lymph node region. The 18F-fluorodeoxyglucose positron emission tomography/CT showed no abnormal accumulation on the transverse colon; however, an abnormal accumulation was found at the enlarged lymph node. The patient was preoperatively diagnosed as having advanced transverse colon cancer with lymph node metastasis and underwent laparoscopic right hemicolectomy with D3 lymph node dissection. Pathological examination showed only a scar-like tissue and no cancerous lesion in the transverse colon, while a metastatic lymph node was histologically confirmed in the intermediate lymph node region. Loss of MLH1 and PMS2 expression was observed in the cancer cells of both biopsy specimens and resected lymph nodes. No recurrence was seen for 5 years after surgery.

CONCLUSIONS

We reported a rare case of SR of the primary transverse colon cancer without regression of the metastatic regional lymph node. We considered that colorectal cancer with SR should be resected because even if SR of the primary lesion occurs, lymph node metastasis might have an inconsistent behavior as shown in the present case.

Chance to rein in a cancer--Spontaneous regression of lung carcinoma (1988-2018): a 30-year perspective

BACKGROUND

Spontaneous regression of tumor is an extremely rare phenomenon in the oncology field and even rarer for lung cancer. However, the underlying mechanism is poorly understood. Summarizing the available clinical information and the supposed mechanism shed new light on lung cancer therapy strategies in the new era of immunotherapy.

SUMMARY

We conducted a PubMed search using the retrieval tactics ("Lung Neoplasms" [Mesh]) AND "Neoplasm Regression, Spontaneous" [Mesh] for reports from 1988 to January 2018, and all references in the relevant literature were subsequently investigated for relevance. Using the criteria of Everson and Cole, 14 cases were finally defined as spontaneous regression and were reviewed in the research. Key messages: The information regarding patient characteristics, treatments, and follow-up has been summarized. In this review, we found that spontaneous lung cancer regression cases fall into two categories including: (1) neurologic disorders in 6 cases, half of whom suffered with paraneoplastic neurological syndromes (PNS) and (2) immunological reactions in 7 cases. Getting data on more spontaneous regression cases and more detailed information will definitely help us understand the mechanism for the body's surveillance system-cancer balance, creating a big chance to increase cancer immunotherapy.

Spontaneous regression of metastatic renal cell carcinoma after cytoreductive nephrectomy: A case report

We herein report a case involving a 59-year-old man with right lung and mediastinal lymph node metastases from renal cell carcinoma. After cytoreductive nephrectomy without neoadjuvant therapy, he achieved spontaneous regression. The regression was maintained 3 years after the operation. We immunohistochemically examined the surgical specimens and considered the possible mechanism underlying this phenomenon.