Testicular Radiomics To Predict Pathology At Time of Postchemotherapy Retroperitoneal Lymph Node Dissection for Nonseminomatous Germ Cell Tumor

INTRODUCTION

Testicular germ cell tumors are the most common malignancy in young adult males. Patients with metastatic disease receive standard of care chemotherapy followed by retroperitoneal lymph node dissection for residual masses >1cm. However, there is a need for better preoperative tools to discern which patients will have persistent disease after chemotherapy given low rates of metastatic germ cell tumor after chemotherapy. The purpose of this study was to use radiomics to predict which patients would have viable germ cell tumor or teratoma after chemotherapy at time of retroperitoneal lymph node dissection.

PATIENTS AND METHODS

Patients with nonseminomatous germ cell tumor undergoing postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) between 2008 and 2019 were queried from our institutional database. Patients were included if prechemotherapy computed tomography (CT) scan and postchemotherapy imaging were available. Semiqualitative and quantitative features of residual masses and nodal regions of interest and radiomic feature extractions were performed by 2 board certified radiologists. Radiomic feature analysis was used to extract first order, shape, and second order statistics from each region of interest. Post-RPLND pathology was compared to the radiomic analysis using multiple t-tests.

RESULTS

45 patients underwent PC-RPLND at our institution, with the majority (28 patients) having stage III disease. 24 (53%) patients had teratoma on RPLND pathology, while 2 (4%) had viable germ cell tumor. After chemotherapy, 78%, 53%, and 33% of patients had cystic regions, fat stranding, and local infiltration present on imaging. After radiomic analysis, first order statistics mean, median, 90th percentile, and root mean squares were significant. Strong correlations were observed between these 4 features;a lower signal was associated with positive pathology at RPND.

CONCLUSIONS

Testicular radiomics is an emerging tool that may help predict persistent disease after chemotherapy.

Anti-N-methyl-D-aspartate receptor-associated encephalitis: A review of clinicopathologic hallmarks and multimodal imaging manifestations

Anti-N-methyl-D-aspartate receptor-associated encephalitis (NMDARE) is a rare immune-mediated neuroinflammatory condition characterized by the rapid onset of neuropsychiatric symptoms and autonomic dysfunction. The mechanism of pathogenesis remains incompletely understood, but is thought to be related to antibodies targeting the GluN1 subunit of the NMDA receptor with resultant downstream dysregulation of dopaminergic pathways. Young adults are most frequently affected; the median age at diagnosis is 21 years. There is a strong female predilection with a female sex predominance of 4:1. NMDARE often develops as a paraneoplastic process and is most commonly associated with ovarian teratoma. However, NMDARE has also been described in patients with small cell lung cancer, clear cell renal carcinoma, and other benign and malignant neoplasms. Diagnosis is based on correlation of the clinical presentation, electroencephalography, laboratory studies, and imaging. Computed tomography, positron emission tomography, and magnetic resonance imaging are essential to identify an underlying tumor, exclude clinicopathologic mimics, and predict the likelihood of long-term functional impairment. Nuclear imaging may be of value for prognostication and to assess the response to therapy. Treatment may involve high-dose corticosteroids, intravenous immunoglobulin, and plasma exchange. Herein, we review the hallmark clinicopathologic features and imaging findings of this rare but potentially devastating condition and summarize diagnostic criteria, treatment regimens, and proposed pathogenetic mechanisms.

Mature cystic teratoma overlapping with giant serous cystadenoma of the ovary: A case report

Ovarian lesions represent a diagnostic challenge for the radiologist and should be approached according to the patient's age, menstrual cycle, and imaging characteristics. These lesions can be cystic, mixed, or solid-predominant structures. Generally, the occurrence of benign lesions surpasses that of malignant ones at a ratio of 3:1. However, within infantile and juvenile age groups, this becomes an infrequent occurrence, making up only about 5% of ovarian tumor cases. This case report sheds light on a unique scenario involving a pediatric patient who harbored 2 benign tumors simultaneously: a mature cystic teratoma and a serous cystadenoma.

[Low-grade astrocytoma within a retroperitoneal teratoma: Case report]

Teratomas are neoplasms originate from germ cells and can undergo malignant transformation, the World Health Organization (WHO) classified them as teratoma with somatic-type malignancy which is uncommon and sarcomas are the histological type with the highest incidence. It is important to identify this type of tumors because influences the prognosis and survival of the patient. We present the case of a 5-month-old male, who began his condition at one month-old with constipation and increase of the abdominal circumference, imaging studies revealed an abdominal lesion, he was treated with chemotherapy and surgery. The histopathological report was immature teratoma, grade 1, with a focus of nervous tissue showing characteristics of low-grade astrocytoma.

PET/CT Examination of Teratomas after Stem Cell Transplantation for a Spinal Cord Injury: A Case Report

BACKGROUND

In clinical practice, stem cell transplantation has become an effective method for treating spinal cord nerve injury. Up to now, there has been no report on teratoma caused by transplanted stem cell's abnormal differentiation in the clinic, especially in the analysis of imaging manifestations. Therefore, this article aims to analyze the PET/CT imaging manifestations of teratoma caused by stem cell transplantation to improve the imaging diagnosing capability.

CASE PRESENTATION

A patient with a spinal cord injury who had received a stem cell transplant was examined by PET/CT on September 10th, 2020. The PET/CT images of the lesion showed irregular mixed low density on the right side of the erector spinae muscle area at the level of the cervical 3-5 vertebral body, with a maximum cross-section of 9.1×3.9 cm. The 18F-FDG metabolism of the lesion was increased, and the maximum standard uptake value (SUVmax) was 10.7. The boundary was unclear with the third cervical vertebra and cervical 3 and 4-level vertebral plates. Based on the patient's medical history, the lesion was diagnosed as an abnormal proliferative tumor, which was consistent with the pathological examination results.

CONCLUSION

To date, there have been no clinical reports on teratomas caused by stem cell transplantation for spinal cord injury at home or abroad. This case report enhances the knowledge of the diagnosis and treatment methods of this type of disease and confirms the diagnostic value of PET/CT examination.

[Ovarian masses in infants and children]

BACKGROUND

Abnormalities of the ovary are frequently seen on ultrasound examination, sometimes symptomatic, but are more commonly asymptomatic.

PURPOSE

Presentation of the most important entities of ovarian masses and their imaging features in infants and children. Discussion of criteria for differentiation between benign and potentially malignant masses.

MATERIALS AND METHODS

Review of current literature and presentation of image examples.

RESULTS

The most common lesions are ovarian cysts in infants, which usually do not require therapy. Because of the risk of torsion, surgery should be discussed for lesions with a size of 5 cm or more. Benign teratomas represent three-quarters of all solid tumors of the infantile ovary. Malignant masses are rare. The task of imaging is to assess the potential risk of malignancy, also using imaging scores.

CONCLUSIONS

Imaging plays a crucial role for therapeutic considerations. Depending on the potential risk, ovarian-sparing surgery is preferred to preserve fertility, as long as the oncologic risk is reasonable.

Anesthetic Care During Exploratory Laparotomy and Excision of a Fetus-in-Fetu With a Combined General-Regional Anesthetic Technique Using a Caudal Epidural Catheter

Fetus-in-fetu (FIF) is a rare, congenital anomaly involving the presence of one of a pair of twins within the body of the other. It is postulated that this pathology occurs during embryogenesis of a diamniotic-monochorionic twin pregnancy with unequal division of the blastocele, which results in monozygotic, monochorionic, and diamniotic twins of unequal sizes. Presentation as an abdominal mass during the neonatal period or infancy is most common, although late diagnosis during the adult years may also occur. We report a 1-day-old, full-term female neonate who presented for exploratory laparotomy and excision of a FIF. We present the use of a combined general-regional technique using caudal epidural anesthesia. The etiology, presentation, appropriate workup, and treatment of FIF are presented. Previous anecdotal reports of anesthetic care for excision of FIF are reviewed.

A huge mediastinal teratoma in a 14-year-old girl

INTRODUCTION AND IMPORTANCE

Mediastinal teratoma is the most common mediastinal germ cell tumor. Mature mediastinal teratomas are infrequent and often found incidentally.

CASE PRESENTATION

We report the case of a 14-year-old girl who was presented dyspnea for 2 years. A computed tomography of the chest revealed a 19 cm heterogenous right-sided anterior mediastinal mass suggesting mature teratoma. The mass compressed vital structures. The tumor was considered resectable. By hemiclamshell approach, we punctured the tumor and aspirated its contents. The tumor was totally resected en bloc with a cuff of pericardium, phrenic nerve and azygos vena. The pericardial defect was repaired using Mersilene mesh. Histopathology of the tumor revealed a mature cystic teratoma. Postoperative course was uneventful.

CLINICAL DISCUSSION

Complete surgical excision is the treatment of choice for mediastinal mature teratoma. The choice of incision for removing the tumor depend on the tumor size, location and the relashionships with the associated vital structures. Lengthy incisions were required for the safe mobilization of the tumor. In addition, contents aspiration through a small incision in the giant tumor wall helped improve tumor mobilization.

CONCLUSION

Appropriate surgical strategy for a well selected case maintains functional status and results total tumor resection.

Mature Cystic Teratoma of the Ovary Transforms into Squamous Cell Carcinoma: A Case Report

Mature cystic teratomas (MCTs) are benign ovarian tumors known to undergo malignant transformation in 1%-2% of cases. Most of these cases lead to squamous cell carcinomas (SCC), and the prognosis is often poor, particularly in advanced-stage disease. A 50-year-old postmenopausal woman presented with a large pelvic mass. The patient initially underwent suboptimal primary surgery and was later diagnosed with stage IIIA SCC arising from MCT. Following the first cycle of chemotherapy with carboplatin and paclitaxel, a computed tomography scan showed a rapidly growing large mass in the pelvic cavity after 4 weeks of primary surgery, leading to a second debulking surgery. However, the patient underwent only one cycle of chemotherapy after secondary debulking surgery because of her poor performance status. Subsequently, after 4 months of secondary debulking surgery, the patient developed rapidly progressive disease, leading to her death approximately after 8 months of diagnosis. While an appropriate multimodal treatment strategy has yet to be established, optimal cytoreductive surgery and adjuvant chemotherapy should be considered for treatment of advanced-stage diseases to improve survival outcomes.

Development and validation of a nomogram for preoperative prediction of immature teratoma in children with teratoma: a retrospective, multicenter, diagnostic study

Background

Teratomas are the most common germ cell tumors in children, and histologically classified as mature teratomas (MTs) and immature teratomas (ITs). Preoperative IT identification can affect the surgical approach, the type of procedure, and future possible reproductive health. However, there is no complete diagnostic criterion for ITs nowadays. We aimed to establish and validate a nomogram based on clinical and computed tomography (CT) features for preoperative prediction of ITs in children.

Methods

We retrospectively reviewed 519 teratoma patients from hospital I for training (n=364) and validation (n=155), and 113 patients from hospital II for external validation. Univariate and multivariate logistic regression analyses were performed on the training set to screen risk factors, including alpha-fetoprotein (AFP), age, gender, tumor site, size, tumor composition, calcification and fat. Then, a nomogram was established based on identified risk factors and validated on the validation set. The performance of the nomogram was evaluated in terms of discrimination, calibration and the clinical usefulness.

Results

Multivariate logistic regression showed that tumor composition, AFP, age, calcification and fat were independent risk factors for preoperative prediction of IT. The area under the receiver operating characteristic (ROC) curves (AUCs) for the nomogram on the training set, internal and external validation set were 0.92 (0.88-0.96), 0.91 (0.84-0.97) and 0.92 (0.86-0.97), respectively. The model demonstrated sensitivity of 80%, specificity of 90% at the cut-off value of 0.262. Whatever the set, the calibration curve indicated good calibration. Decision curve analysis (DCA) curves demonstrated that the nomogram had greater net benefits than either the treat-all tactics or the treat-none tactics within a large scope of threshold.

Conclusions

The nomogram established based on clinical and CT findings had the favorable accuracy for the preoperative prediction of IT, and may help in clinical decision-making and risk stratification.

[Fundamentals in the pathology of testicular germ cell tumours]

Testicular germ cell tumours (GCT) represent the most common malignant neoplasia in young male adults between the age of 15 and 44. Because of their different biological behaviour it is important to differentiate prepubertal GCTs from postpubertal GCTs. This distinction is made by presence or absence of a germ cell neoplasia in situ. Histopathological diagnostics can be challenging due to different tumour subtypes and their different growth patterns. Therefore, knowledge of morphologic variants and immunohistochemical markers is important.

A massive immature mediastinal teratoma treated with chemotherapy and surgical resection: a case report

BACKGROUND

Teratoma is a type of germ cell tumor consisting of one or multiple tissues derived from germinal layers. The location and size of the tumor can cause various presentations. Here we report one of the largest ever cases of immature cystic teratoma.

CASE PRESENTATION

In this report, we presented a 24-year-old patient with dyspnea, chest pain, nausea, and anorexia. A computed tomography scan revealed a giant, right-sided mass measuring about 190 × 150 × 140 mm. Chemotherapy was initiated for the patient, followed by thoracotomy. Histopathological evaluation revealed the nature of the mass to be an immature mediastinal teratoma.

CONCLUSION

the incidence of immature mediastinal teratoma is uncommon, and due to its rarity, the diagnosis needs more profound evaluation studies such as radiological and pathological assessments. Immature teratomas are optimally treated by a combination of chemotherapy and complete resection.

Cervicomedullary junction mature teratoma with pulmonary differentiation and diastematomyelia in an adult - A rare case

Background

Intradural extramedullary teratomas in the cervical or cervicomedullary region are rare in adults.

Case Description

We report a symptomatic, mature teratoma at the cervicomedullary junction in a 52-year-old Hispanic female who also has a type I diastematomyelia in the thoracolumbar spine. The patient underwent surgical resection of the lesion with the resolution of presenting symptoms. Histopathology of the lesion revealed a mature cystic teratoma with pulmonary differentiation.

Conclusion

We discuss the case along with a review of pertinent literature and considerations with regard to the diagnosis, etiology, prognosis, and management of this unusual pathology.

Typical and atypical magnetic resonance imaging manifestation of ovarian mature cystic teratomas: A report of two cases

The mature teratoma, also known as a dermoid cyst, is the most common type of ovarian teratoma (OT). They constitute 95% of all teratomas and 69% of germ cell tumors, and their heterogeneity leads to various clinical manifestations with a wide range of imaging presentations. We presented 2 patients undergoing pelvic magnetic resonance imaging (MRI) showing a mature cystic teratoma and pathologic examination confirming typical and atypical findings.

A spontaneous ovarian teratoma in an FVB/n female mouse: Case report and literature review

Background

Teratomas are rare types of germ cell neoplasms composed of various differentiated or undifferentiated tissues.

Case Description

A 25-week-old female control FVB /n mouse in a 4-week toxicity study presented abdominal distension and poor body condition. It was euthanized, and the necropsy examination revealed a large mass connected to the tip of the right uterine horn, occupying the entire abdominal cavity. Microscopically, this mass showed areas of epidermal differentiation, with laminated keratin and sebaceous glands, differentiation into respiratory and digestive epithelium, cartilage, bone, and extensive areas of differentiation into the nervous tissue, being classified as an ovarian teratoma.

Conclusion

As far as authors know, the occurrence of ovarian teratomas in the FVB/n mouse strain has never been previously described.

Mature cystic teratoma without intratumoral fat: A diagnostic dilemma

Teratomas are the most common benign ovarian neoplasms in young women. Typical computed tomography imaging findings include fat, fat fluid level, tooth or calcification, rokitansky nodule, floating balls sign, and tufts of hair. They can have unusual imaging features leading to diagnostic dilemmas. Studies have shown the presence of intratumoral fat to be specific to ovarian cystic teratoma. However, there are reports in the literature of mature cystic teratoma that do not contain fat in the lumen of the cyst which can hinder an accurate diagnosis. They can be associated with various complications like torsion, rupture, malignant transformation, infection, and autoimmune hemolytic anemias. Presented here is a case of mature cystic teratoma without visible intracystic fat which underwent torsion.

Mature cystic teratoma of the ovary with malignant transformation of tall cell subtype of papillary thyroid carcinoma

Malignancies rarely occur in somatic parts of mature cystic teratoma of the ovary. Squamous cell carcinoma is the most common form of cancer that can develop in mature cystic teratoma. Other less frequent malignancies include melanoma, sarcoma, carcinoid, and germ cell neoplasms. Only three cases have been reported as papillary thyroid carcinoma arising in struma ovarii. We present a unique case of a 31-year-old female patient who presented with a left ovarian cyst and underwent conservative surgical management in the form of cystectomy. Histopathological examination confirmed the diagnosis of a tall cell subtype of papillary thyroid carcinoma arising from a small focus of thyroid tissue in a mature cystic teratoma of the ovary. The patient was followed up for 60 months with an uneventful clinical course. For a better understanding of such rare cancers, collaborative retrospective studies on large databases with other medical centers are required.

Quantitative analysis of a posterior fossa teratomas with unusual CT and MR Characteristics--illustrative case

BACKGROUND

Intracranial teratomas or other cystic lesions with atypical imaging manifestations can still be frequently seen clinically. The specific reasons for unusual imaging manifestations need to be further explored.

OBSERVATIONS

A case of adult teratoma in the posterior fossa with unusual imaging manifestations was reported. The chemical composition of its cystic fluid was quantitatively detected, and in vitro imaging simulation experiments were performed on some fluid substances with similar cystic fluid properties to explore the reasons for special imaging manifestations. The content of inorganic substances and protein in the cystic fluid were both low, with no melanin detected. In vitro experiments revealed that MR T1 signals could increase with protein content rising and changes in MR T2 signals presented no obvious correlation with it. CT values increased gradually with protein concentration rising. The substances with similar viscosity had similar CT values, whereas substance viscosity showed no significant correlation with changes in MR signals.

CONCLUSION

The abnormality of imaging manifestations cannot be confirmed as the result of "high protein content", nor can it be simply attributed to bleeding. Further research is required for the impact of the combination of paramagnetic particles and biofluid on imaging.

Mucinous Adenocarcinoma and Carcinoid Tumor Arising Within an Ovarian Mature Cystic Teratoma: A Case Report

The coexistence of both mucinous adenocarcinoma and carcinoid tumor within an ovarian mature cystic teratoma is extremely rare. We report a case of an 18-year-old Omani woman with a left ovarian cyst. After laparotomy with left salpingo-oophorectomy, omentectomy, and peritoneal washings, the excised cyst had the typical morphology of mature cystic teratoma with grade I mucinous adenocarcinoma and a focus of carcinoid tumor.

Ruptured teratoma mimicking a pelvic inflammatory disease and ovarian malignancy: A case report

BACKGROUND

We report a case of ruptured ovarian teratoma mimicking pelvic inflammatory disease (PID) and ovarian malignancy. The case indicates the need for reviewing the information on ovarian teratomas, as the symptoms are vague, and, therefore, diagnosis and treatment had to be structured accordingly.

CASE SUMMARY

A 60-year-old woman was admitted to the emergency department with acute lower abdominal pain. She experienced weight loss and increased abdominal girth. Pelvic ultrasound and computed tomography revealed a 14-cm pelvic tumor. Laboratory examination revealed leukocytosis (white blood cell count: 12620/μL, segment: 87.7%) and high levels of C-reactive protein (18.2 mg/dL). Elevated levels of the tumor marker cancer antigen 19-9 (367.8 U/mL, normal value < 35 U/mL) were also noted. Due to the impression of a ruptured tubo-ovarian abscess or a tumor with malignancy, she immediately underwent an exploratory laparotomy. A ruptured ovarian tumor with fat balls, hair strands, cartilage, and yellowish fluid was observed on the right side. Right salpingo-oophorectomy was performed. A pathological examination revealed a mature cystic teratoma. The patient recovered after surgery and was discharged on post-operative day three. No antibiotics were administered.

CONCLUSION

This case illustrates the differential diagnosis of an ovarian tumor. Therefore, surgery is the mainstay for treating a ruptured teratoma.

Hand-assisted laparoscopic surgery on a gigantic primary retroperitoneal mature cystic teratoma: A case report

INTRODUCTION

Primary teratomas in the retroperitoneum are rare, incidentally identified in children, and resected using a laparoscopic approach. However, when it increases in size, the laparoscopic approach is technically demanding, leaving a large skin incision for tumor removal.

PRESENTATION OF CASE

The patient was a 20-year-old woman who presented with chronic left flank pain. Abdominal and pelvic computed tomography (CT) revealed a 25-cm wide giant polycystic and solid retroperitoneal tumor containing calcification located in the upper portion of the left kidney, strongly compressing the pancreas and spleen. No other metastatic lesions were observed. Additionally, abdominal magnetic resonance imaging (MRI) revealed that the polycystic tumor consisted of serous fluid and fatty components, and bone and tooth components were found in the tumor center. Therefore, the patient was diagnosed with retroperitoneal mature teratoma and a hand-assisted laparoscopic surgery using bikini line skin incision was performed. The specimen was 27 × 25 cm in size, weighing 2512 g. Histology revealed that the tumor was a benign, mature teratoma without a malignant component. The postoperative course was uneventful and the patient was discharged on postoperative day 7. The patient remained healthy without any recurrence and the postoperative scar is barely visible under direct vision.

DISCUSSION

Primary retroperitoneal mature teratomas can enlarge without initially causing symptoms and can be incidentally identified using imaging studies.

CONCLUSION

A hand-assisted laparoscopic approach using a bikini line skin incision is safe, minimally invasive, and provides better cosmesis.

Giant teratoma with isolated intestinal duplication in adult: A case report and review of literature

BACKGROUND

A combination of diseases is a rare phenomenon. Their clinical manifestations can vary, and the diagnosis can be challenging. Intestinal duplication is a rare congenital malformation, whereas retroperitoneal teratoma is a tumor in the retroperitoneal space, derived from the remaining embryonic tissue. There are relatively few clinical findings on adult retroperitoneal benign tumors. It is hard to believe that these two rare diseases can happen to the same person.

CASE SUMMARY

A 19-year-old woman complaining of abdominal pain with nausea and vomiting was admitted. Abdominal computed tomography angiography was suggested for invasive teratoma. Intraoperative exploration revealed that the giant teratoma was connected to an isolated intestinal tract in the retroperitoneum. The postoperative pathological examination revealed that mature giant teratoma was present with intestinal duplication. This was a rare intraoperative finding that was successfully treated surgically.

CONCLUSION

The clinical manifestations of intestinal duplication malformation are various, and difficult to diagnose before the operation. The possibility of intestinal replication should be considered when intraperitoneal cystic lesions are present.

A new hypothesis may explain human parthenogenesis and ovarian teratoma: A review study

Parthenogenesis (PG) is a rare phenomenon occurring in humans, and understanding this may help us develop an explanation for such occurrences. Moreover, it may help reveal the cause of idiopathic ovarian teratoma (OT). We aim to explain the occurrence of PG and OT in humans based on a new hypothesis. Previous literature has been searched through relevant scientific websites and international journals on the causes and mechanisms of PG and OT in humans. The previous literature on human PG was sparse and mostly contained case reports. It appears that human PG is not as rare as previously reported but may occur spontaneously, resulting in OT formation. The difference between PG and sexual reproduction is that PG has no embryonic diversity. The biopsied embryonic samples in the PG correspond exclusively to those of the maternal side. Spontaneous PG in humans often degrades or leads to formation of OT. The cause and mechanism of spontaneous PG remain unclear in the available literature. Here, we hypothesized that in some cases the secondary oocyte and first polar body enclosed in the zona pellucida may fuse together to form a single cell that restores the diploid number of chromosomes and initiates cell division to form PG. It may go unnoticed or be represented by the OT. Future studies are recommended to investigate this hypothesis.