Primary squamous cell carcinoma of the breast: a case report

INTRODUCTION

Squamous cell carcinoma (SCC) of the breast is a rare variant of invasive breast cancer that has been classified as metaplastic carcinoma. When a tumor is composed of spindle cells, diagnosis is challenging.

CASE REPORT

A 42-year-old woman with a large mass in the right breast underwent modified radical mastectomy. A pathological examination revealed a tumor with central necrosis in it. The tumor had a sarcomatoid growth pattern and the cells were spindle-shaped with severe atypicality. Immunohistochemical staining showed that P63, P53, vimentin, and CKpan were positive, whereas estrogen receptor and C-erbB-2 were negative. Ki-67 proliferation index was as high as 90%. Therefore, a diagnosis of SCC of the right breast was made. The patient received eight cycles of postoperative chemotherapy with paclitaxel and carboplatin, followed by seven cycles of radiotherapy. During follow-up, the patient also had a left thyroid tumor, and postoperative pathology suggested microinvasive follicular carcinoma. Since breast surgery, the patient has remained disease-free for more than four years.

CONCLUSION

SCC of the breast with spindle cell and sarcomatoid features is rare. The diagnosis of such tumors requires exclusion of tumors with similar histological morphologies.

Spindle cell embryonal rhabdomyosarcoma of the prostate in an adult patient: a case report and review of the literature

Rhabdomyosarcoma of the prostate is a rare mesenchymal tumor that originates from undifferentiated mesenchymal cells. Spindle cell rhabdomyosarcoma is a variant of embryonal rhabdomyosarcoma. The vast majority of these two pathological types occur in children, with only a few adult cases reported to date, and both are associated with poor clinical outcomes. We herein report a case involving a man in his early 40s with spindle cell embryonal rhabdomyosarcoma of the prostate. His chief complaint was difficult urination. The diagnosis was confirmed by puncture biopsy of the prostate, and pelvic lymph node metastasis was already present at the time of diagnosis. The patient underwent three courses of chemotherapy. However, his response to the treatment was very poor, and he died of the disease 4 months after diagnosis.

Clear and Spindle Cell Dedifferentiation in Ameloblastic Carcinoma: A Case Report on a Uncommon Phenomenon

Ameloblastic carcinoma is a rare malignant neoplasm with characteristic histopathological features that are directed towards an aggressive surgical approach than benign odontogenic lesions. It affects people of all ages, mostly in the posterior mandible, without a preference for race or gender. De novo cancer is one of its primary types, while the second type is defined as a malignant change from an antecedent case of benign ameloblastoma. The rapid progression of molecular biology led to the revelation that ameloblastoma contains a BRAF-V600E genetic mutation over 60%. Besides conventional ameloblastic carcinomas, rare histologic variants have also been described in the literature, including clear and spindle cells. These variants pose diagnostic challenges as to whether it is a dedifferentiation or a distinct entity. The dearth of data lends credence to the notion that these histologic variations are related to high-grade neoplasms and more aggressive outcomes. As a result, the current report intends to analyze a series of patients diagnosed with conventional ameloblastic carcinoma of the head and neck region with spindle and clear cell types along with a brief assessment of the literature.

Inflammatory Pseudotumor of Neck (anterior aspect) in a Child: A Rare Case Report

Inflammatory pseudotumor mostly occurs in the lungs and orbit, with only 15% occurring in the nonorbital head and neck region. We hereby present a 2 year old child with a progressive swelling over the anterior aspect of neck since 7 months, that was insidious in onset and gradually progressive in nature. MRI of neck and FNAC were inconsistent with our diagnosis. Post op HPE confirmed it to be Inflammatory Pseudotumor. So inflammatory pseudotumor should be considered as differential diagnosis of neck swelling and treated accordingly.

Metaplastic Breast Cancer: Current Understanding and Future Directions

Metaplastic breast cancers (MBC) encompass a group of highly heterogeneous tumors which share the ability to differentiate into squamous, mesenchymal or neuroectodermal components. While often termed rare breast tumors, given the relatively high prevalence of breast cancer, they are seen with some frequency. Depending upon the definition applied, MBC represents 0.2% to 1% of breast cancers diagnosed in the United States. Less is known about the epidemiology of MBC globally, though a growing number of reports are providing information on this. These tumors are often more advanced at presentation relative to breast cancer broadly. While more indolent subtypes exist, the majority of MBC subtypes are associated with inferior survival. MBC is most commonly of triple-negative phenotype. In less common hormone receptor positive MBCs, hormone receptor status appears not to be prognostic. In contrast, relatively rare HER2-positive MBCs are associated with superior outcomes. Multiple potentially targetable molecular features are overrepresented in MBC including DNA repair deficiency signatures and PIK3/AKT/mTOR and WNT pathways alterations. Data on the prevalence of targets for novel antibody-drug conjugates is also emerging. While chemotherapy appears to be less active in MBC than in other breast cancer subtypes, efficacy is seen in some MBCs. Disease-specific trials, as well as reports of exceptional responses, may provide clues for novel approaches to this often hard-to-treat breast cancer. Strategies which harness newer research tools, such as large data and artificial intelligence hold the promise of overcoming historic barriers to the study of uncommon tumors and could markedly advance disease-specific understanding in MBC.

The Challenge of "Monomorphic" Mucoepidermoid Carcinoma-Report of a Rare Case with Pure Spindle-Clear Cell Morphology

BACKGROUND

Mucoepidermoid carcinoma is a malignant salivary gland tumor which, in most cases, is composed of variable proportions of mucous, epidermoid, and intermediate cells.

METHODS

We report a case of parapharyngeal mucoepidermoid carcinoma with highly unusual ("monomorphic") light microscopic features as well as atypical immunohistochemical properties. Molecular analysis was performed using the TruSight RNA fusion panel.

RESULTS

The tumor featured heretofore undescribed histopathological features: sheets and nests composed of monomorphic neoplastic (plump spindle to epithelioid) cells with no mucous, intermediate, glandular/columnar, or any other cell type identified. The neoplastic cells displayed variable clear cell change and only expressed cytokeratin 7. Despite this non-classical morphology, the presence of the classical CRTC1::MAML2 fusion was demonstrated.

CONCLUSIONS

Mucoepidermoid carcinoma featuring a uniform ("monomorphic") population of neoplastic cells is a novel observation. A confident diagnosis of mucoepidermoid carcinoma can be made upon detection of the CRTC1/3::MAML2 fusion. Our case increases the spectrum of histopathological appearances that mucoepidermoid carcinoma may display.

Clinical perspectives and outcomes of the giant breast phyllodes tumor and sarcoma: a real-world retrospective study

BACKGROUND

Giant breast malignant phyllodes tumor or sarcoma (GBPS) are rare entities with diameter larger than 10 cm and variously histological pleomorphisms. This disease poses a significant threat to the quality of life of individuals, and its prognosis remains unclear. This study aimed to explore the differential diagnosis, treatment, and prognosis of GBPS in a real-world retrospective cohort.

METHODS

We collected GBPS (diameter > 10 cm, n = 10) and BPS (diameter ≤ 10 cm, n = 126) from patients diagnosed with sarcoma or malignant phyllodes tumor between 2008 and 2022. We analyzed clinical characteristics, histological status, treatment, and local recurrence using the Fisher's exact test between GBPS (diameter > 10 cm) and BPS (diameter ≤ 10 cm) cohort. We described overall survival (OS) and disease-free survival (DFS) using Kaplan-Meier curves and identified risk factors for local recurrence using logistic regression. The tumor size, age at diagnosis, and differential immunohistochemistry markers of breast sarcoma or phyllodes tumor to determine the prognosis of GBPS.

RESULTS

In our retrospective analysis of breast malignancies, we identified 10 cases of GBPS and 126 cases of BPS, corresponding to a GBPS prevalence of 0.17% (10/6000). The median age was 38.5 years (inter-quartile range, IQR: 28.25-48.5 years). During the follow-up of period (median: 80.5 months, IQR: 36.75-122 months), the local recurrence (LR) rate was 40% and 20.6%, respectively. Clinical characteristics of young age (HR:2.799, 95%CI -00.09276-0.017, p < 0.05) and cytological characteristics of marked stromal atypia (HR:0.88, 95% CI 0.39-1.40, p < 0.05) were risk factors for the poor prognosis of GBPS by COX regression model analysis. The Kaplan-Meier curves of GBPS 5-year disease-free survival (DFS) and overall survival (OS) were 31.5 months and 40 months, respectively, and were not associated with adjuvant radiation or chemotherapy.

CONCLUSION

We recommend mastectomy with a clear surgical margin as the preferred treatment for GBPS. Age and stromal atypia are significantly associated with recurrence. Adjuvant radiation therapy is advised; however, there was no improvement in overall survival. There is no consensus on the effectiveness of adjuvant chemotherapy and genetic methods, highlighting the need for further research into this aggressive tumor. We recommend a multidisciplinary approach involving a dedicated team for the management of GBPS.

Papillary thyroid carcinoma with nodular fasciitis-like stroma - an unusual variant with distinctive histopathology: A case report

BACKGROUND

Papillary thyroid carcinoma (PTC) is regarded as a fairly common endocrine malignancy, which can be divided into different multiple variants due to wide morphologic differences. The majority of PTC variants have been reported, but PTC with nodular fasciitis-like stroma (NFS) is a rare pathological variant and has been infrequently reported in the relevant literature. This condition involves abundant reactive stromal components rich in spindle cells, which may account for 60%-80% of the tumor along with a typical papillary carcinoma.

CASE SUMMARY

A 44-year-old man presented with a 4-mo history of a palpable mass over the anterior aspect of the left neck, the tumor demonstrated gradual enlargement but was painless during the 4 mo prior to discovery. Thyroid function test results were normal. Physical examination showed an enormous and firm nodular mass in the left lobe of the thyroid gland extending to the level of the hyoid bone. Ultrasonography of the neck revealed a well-defined heterogeneous lesion measuring around 5.0 cm × 4.0 cm with a hypoechoic complex nodule, decreased vascularity and speckles of microcalcification. The patient underwent left thyroidectomy with central compartment lymph node dissection. Final histopathological examination confirmed the diagnosis of PTC with extensive fibromatosis-like stroma combined with typical PTC. The patient was asymptomatic at the 3-mo follow-up.

CONCLUSION

PTC-NFS is a rare pathological variant and its diagnosis and prognosis may be similar to typical papillary carcinoma.

"PRRX1-rearranged mesenchymal tumors": expanding the immunohistochemical profile and molecular spectrum of a recently described entity with the proposed revision of nomenclature

Since the publication of the 2020 World Health Organization classification of soft tissue and bone tumors, the classification of "fibroblastic" tumors has expanded to include a novel subset of tumors characterized by PRRX1::NCOA1/2 gene fusions. These tumors defy conventional classification and are morphologically distinct, characterized by a multi-nodular growth of bland spindle cells suspended in a myxo-collagenous stroma with mild cytologic atypia, "staghorn-like" vessels, and variable perivascular hyalinization. Mitotic activity is rare, and necrosis is not identified. Herein, we present six additional cases of PRRX1-rearranged mesenchymal tumors, including five cases with PRRX1::NCOA1 fusion and one case with PRRX1::KMT2D fusion. Three cases (3/6, 50%) demonstrated focal co-expression of S100 protein and SOX10, thereby expanding the immunohistochemical profile of this emerging entity. Like prior reported cases, there was no evidence of malignant behavior on short-term follow-up. The novel fusion, PRRX1::KMT2D, further expands the molecular spectrum of this entity and leads to a proposed revision of the provisional nomenclature to "PRRX1-rearranged mesenchymal tumor" to both accommodate non-NCOA1/2 fusion partners and allow for the possibility of partial neural or neuroectodermal differentiation.

Epidemiology of Unconventional Histological Subtypes of Urethral Cancer

INTRODUCTION

The aim of the study was to examine cancer-specific mortality (CSM) of unconventional urethral cancers.

METHODS

Within the SEER (2004-2016) database, we analyzed CSM of 165 patients with unconventional urethral-cancer histology. Kaplan-Meier plots were used to test the effect of unconventional histologies in urethral cancer on CSM.

RESULTS

Of 165 eligible patients, the Mullerian type accounted for 55 (33.3%) versus melanocytic (26.7%) versus neuroendocrine 25 (15.2%) versus lymphoma 22 (13.3%) versus mesenchymal/sarcoma 15 (9.1%) versus spindle cell 4 (2.1%) patients. Median age at diagnosis was 81 years in spindle cell, 75 in melanocytic, 74 in neuroendocrine and mesenchymal/sarcoma, 67 in lymphoma, and 62 years Mullerian type (p < 0.001). Of all, 116 (70.3%) were female. The Mullerian type exhibited the highest female ratio (96.4%) versus the lowest female ratio in neuroendocrine (24.0%). The Mullerian type was most frequent in African-American females. In Caucasian females, the melanocytic type was most frequent (49.1%). In African-American (38.9%) and Caucasian males (33.3%), neuroendocrine histology was most frequent. Three-year CSM was, respectively, 27.5%, 23.1% 22.3%, 20.5%, and 16.1% for melanocytic, mesenchymal/sarcoma, Mullerian type, neuroendocrine, and lymphoma histology. Median cancer-specific survival was 106 versus 10 months for combined nonmetastatic versus metastatic nonconventional histologies.

CONCLUSION

Important age, sex, racial/ethnic group distribution, and survival differences exist between each unconventional urethral-cancer histological subtypes.

Low-grade fibromyxoid sarcoma of the vulva presenting as a cystic mass: A case report and review of literature

INTRODUCTION

Low-grade fibromyxoid sarcoma (LGFMS) is a tumor with a propensity for late recurrence which is rarely described in the vulva.

CASE PRESENTATION

A 22-year-old woman presented with a growing right vulvar cystic mass that had been present for 2 months. She underwent surgical wide excision. The final pathologic diagnosis revealed LGFMS of the vulva and a right radical hemivulvectomy with negative margins was performed.

RESULTS

The patient has not experienced a local or metastatic recurrence after 2-years follow- up.

CONCLUSIONS

Despite being rare, LGFMS of the vulva should be taken into account when making a diagnosis of vulvar lesions. Definite diagnosis is based on pathological examination. MUC4 positivity is characteristically expressed. To prevent future recurrences, radical excision is necessary.

Epithelioid fibrous histiocytoma: three diagnostically challenging cases with novel ALK gene fusions, unusual storiform growth pattern, and a prominent spindled morphology

Epithelioid fibrous histiocytoma (EFH) is a distinctive cutaneous neoplasm with a relatively variable morphological appearance. Recently, it has been shown that this tumor is molecularly characterized by ALK gene fusions. We report three EFHs with unusual histological presentation represented by a prominent/predominant spindle cell proliferation arranged in a variably storiform/whirling architectural pattern with or without stromal sclerosis. One of the cases closely resembled cellular fibrous histiocytoma. All three cases were immunohistochemically ALK-positive and were analyzed for ALK gene rearrangements using a next-generation sequencing-based assay (FusionPlex Sarcoma Kit, ArcherDx). Three novel fusions, namely AP3D1::ALK, COL1A::ALK, and LRRFIP2::ALK, were detected and further confirmed by FISH in all 3 cases and RT-PCR in 1 case. All patients were elderly (62-63 years) and presented with a solitary polypoid lesion on the extremities. The awareness of these morphological variants is important since it entertains a wide and slightly different differential diagnosis than conventional EFH. We also presented evidence that a clear separation of EFH from BFH in all cases may not be as straightforward as previously thought. The consistent ALK immunoexpression and the continually expanding scale of ALK gene rearrangements provide a useful tool to distinguish EFH from its histologic mimics.

Follicular dendritic cell sarcoma of gastrointestinal tract with two emerging distinct subtypes: a case report and systemic review

BACKGROUND

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm of mesenchymal origin. FDCS of gastrointestinal tract (GI) are exceedingly uncommon.

CASE PRESENTATION

We report the first case of classic type FDCS in a 34-year-old male with Birt-Hogg-Dubé syndrome, which presented as a mass at the ileo-cecal junction. He received no further treatment after resection and remained disease free for 3.5 years. We further analyze and review the clinical and pathologic findings of 33 cases of GI tract FDCS reported in the literature.

CONCLUSIONS

There are two distinct subtypes of FDCS in the GI tract: the classic type occurs in relatively younger patients (mean = 45.3 years) without Epstein-Barr virus (EBV) association, and behaves more aggressively; the inflammatory subtype presents as colonic polypoid tumor in older patients (mean = 60.7 years) and is EBV positive. The clinical outcome in the latter group appears favorable although mortality rate is not necessarily low.

Large retroperitoneal atypical spindle cell lipomatous tumor, an extremely rare neoplasm: A case report

BACKGROUND

Atypical spindle cell lipomatous tumor (ASLT) is a rare soft tissue neoplasm with a low potential for malignancy. ASLT frequently occurs in the limb and limb girdles. However, large retroperitoneal ASLTs are extremely rare. There was no concrete case report of retroperitoneal ASLTs.

CASE SUMMARY

An 18-year-old woman presented with abdominal pain and a palpable mass. Abdominal computed tomography revealed a large fatty mass that was approximately 30 cm in size and filled the entire abdominal cavity. Surgical excision was indicated. The tumor did not invade the adjacent organs. The pelvic cavity was then too narrow to dissect smoothly. The mass was successfully excised without tumor rupture or adjacent organ injury. Microscopically, the neoplasm was a well-differentiated adipocytic neoplasm. Immunohistochemical staining showed that the spindle cells were positive for CD34 and desmin, in addition to multifocal positivity for S100 protein. These histological features were consistent with an ASLT. The patient’s postoperative course was uneventful. At the 12-mo follow-up, no evidence of recurrence or metastasis was observed.

CONCLUSION

To the best of our knowledge, our study is the first concrete report of a large retroperitoneal ASLT in the English literature. In the large retroperitoneal ASLT located in the pelvic cavity, which made it too narrow and tight to dissect, complete excision is difficult but very important because of recurrence risk. Although large retroperitoneal ASLTs are considered extremely rare, their detection is important for accurate evaluation and management. Owing to their significant rarity, retrospective multicenter case studies are required to determine the clinicopathologic characteristics.

Spindle Variant Primary Diffuse Large B Cell Lymphoma of the Colon: Case Report and Literature Review

Diffuse large B cell lymphoma (DLBCL) with spindle cell morphology is a rare variant that can be seen in extranodal regions. Because the spindle cell dominant morphology in lymphoma is extremely unusual, the diagnosis can easily be missed in many organ systems. We present a case of an 82-year-old male patient with complaints of abdominal pain and swelling. He operated with the preliminary diagnosis of cecum tumor and ileum perforation. Tumoral proliferation was observed originating from the submucosa and infiltrating the muscularis propria, with the features of mostly spindle-shaped, having round-shaped nuclei in some of the cells, and having relatively narrow cytoplasm. A panel of immunohistochemical stains were performed to rule out the possibilities of sarcoma, carcinoma, or melanoma. Diffuse strong positive reaction was observed for CD45, CD20, CD19, CD22, Pax5, and CD30. The case was reported as spindle cell variant of DLBCL based on the present findings. As far as we know, this is the first case described in the colon. We emphasize that pathologists should be reminded of lymphoma as a differential diagnosis of spindle cell tumors.

Metastatic bilateral adrenal sarcomatoid carcinoma: Evaluation by 18F-FDG PET/CT

Sarcomatoid carcinoma of the adrenal gland is an uncommon presentation of malignant adrenal tumors and bilateral presentation is extremely rare. It is an extremely rare occurrence, unusual symptoms, and both epithelioid and sarcomatoid components in histology are a challenge to diagnose sarcomatoid carcinoma of adrenal origin. The majority of patients are diagnosed at a later stage while having metastatic disease and succumb due to disease within a few months of diagnosis due to the aggressive nature of the disease. Probably due to the advanced disease at the time of diagnosis; patients diagnosed having adrenal sarcomatoid tumor have a very poor prognosis. In nonmetastatic disease, adjuvant chemotherapy is suggested after the removal of the tumor. It is essential to diagnose these tumors earliest to treat with effective treatment modalities. The present study describes the rare case of sarcomatoid carcinoma involving the bilateral adrenal gland with metastasis to bones, lymph nodes, and pleura evaluated by ¹⁸F-FDG PET/CT.

Spindle cell variant of medullary thyroid carcinoma: a clinicopathologic study of four cases

Background

Medullary thyroid carcinoma (MTC) is a malignant tumor derived from C cells. It accounts for about 10% of all thyroid malignancies. More than 14 histological variants have been described. Among them, spindle cell variant is extremely rare.

Case presentation

Here we describe 4 cases of spindle cell variant of MTC collected from 2012 to 2019. Ultrasound showed solid and hypoechoic nodules. Three patients underwent total thyroidectomy and regional lymph node dissection, and 1 patient underwent thyroid mass resection. Histologically, the tumors showed spindle shaped cells in bundles or interlaced arrangement, separated by hyalinised fibrous stroma that contained amyloid deposits. Immunohistochemistry showed that the tumor cells were positive for calcitonin, chromogranin A, synaptophysin, CD56, and TTF-1, but negative for other lineage-specific markers.

Conclusions

We report 4 rare cases of spindle cell variant of MTC. Due to its rarity and special morphology, the diagnosis of spindle cell variant MTC relies on its morphology and immunohistochemical markers to avoid misdiagnosis.

Surgical management of advanced pleomorphic dermal sarcoma of the occipital scalp

Pleomorphic dermal sarcoma is a rare neoplasm of mesenchymal origin that most commonly affects the head. We describe the presentation of a 61-year-old man with a 10-week history of an exophytic lesion affecting the occipital scalp, demonstrating rapid growth. The final histopathology revealed a completely excised 9cm pleomorphic dermal sarcoma (pT2aN0M0, Stage 3), one of the largest such lesions reported in the literature to date. This patient's management involved a wide local subperiosteal excision onto the cranium, with a reconstruction with an Integra dermal regeneration template (Integra LifeSciences, Princeton, NJ, USA) and healing with secondary intention. This was mainly due to poorly defined clinical margins on primary excision, the potential for further excision of involved margins (later confirmed as not needed) and the patient's comorbidities, making a return to theatre for definitive reconstruction undesirable.

A case report of a massive cardiac intimal sarcoma manifesting as syncope during a stress test

Background

Syncope has many aetiologies but from a cardiac standpoint, if arrhythmogenic and ischaemic causes are not present, obstructive lesions should be considered. Cardiac spindle cell sarcomas are incredibly rare and difficult to cure.

Case summary

A 62-year-old man presented for exercise stress test and had a syncopal episode on the treadmill. He was found to have a massive mass obstructing the transmitral flow. Patient was taken to the operating room and the mass was resected successfully. Histopathological confirmation revealed the mass to be a cardiac intimal sarcoma. Patient was initiated on a trial regimen of doxorubin, ifosfamide, and mesna.

Discussion

Cardiac intimal sarcomas are aggressive cancers and are difficult to treat; there are no established treatment guidelines. They can lead to obstruction of blood flow through the cardiac chambers. From a cardiac perspective, without arrhythmogenic and ischaemic causes of syncope, obstructive lesions should be considered.

Rapid recurrence of spindle cell type undifferentiated carcinoma early after radical surgery in a bile duct cancer patient - A case report

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An undifferentiated, spindle cell type cholangiocarcinoma (USCC) is extremely rare.

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USCC possesses a high metastatic potential.

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Upfront surgery for USCC was not feasible.

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USCC may be the induction of multidisciplinary treatment.

Introduction

Spindle cell type undifferentiated carcinoma of the extrahepatic bile duct is extremely rare and has a poor prognosis. However, its pathology is not fully known, yet.

Case presentation

76-year-old man with abdominal pain and dark-colored urine was referred to our department. Contrast-enhanced computed tomography showed an enhanced tumor at the junction of the cystic duct and direct invasion of the portal vein. He was diagnosed as having resectable biliary cancer and underwent a subtotal stomach-preserving pancreaticoduodenectomy with a reconstruction of the portal vein. Histopathological findings demonstrated undifferentiated spindle cell carcinoma. Forty-two days post-surgery, he presented with peritoneal dissemination and local recurrence with ascites, and died sixty-five days after his operation.

Clinical discussion

Spindle cell type undifferentiated carcinoma has highly metastatic potentials and also easily invade adjacent organs. Therefore, the prognosis of an undifferentiated, spindle cell type cholangiocarcinoma was poor. Although only surgery ensures cure, multidisciplinary treatment, including chemotherapy and radiotherapy is required.

Conclusion

Although surgery for spindle cell type undifferentiated carcinoma may provide a cure, we must consider the induction of multidisciplinary treatment.

Round Cell Sarcoma with EWSR1-PATZ1 Fusion in the Face of a Five-Year-Old Boy: Report of a Case with Unusual Histologic Features

Round cell sarcomas with EWSR1-PATZ1 fusion are rare polyphenotypic sarcomas that typically show both neural and myogenic differentiation on immunohistochemistry. The histology features lobular admixture of cellular fascicles of relatively monotonous spindle cells and small blue round cells separated by fibrotic stroma. The clinical behavior of EWSR1-PATZ1 sarcoma is uncertain currently with mixed outcomes reported even in cases with metastases. We herein report an additional case of EWSR1-PATZ1 fusion-related round cell sarcoma in the face of a 5-year-old boy with unusual histologic features of pale zones, rosette/gland-like structures and expression of epithelial markers. Fluorescent in-situ hybridization study (FISH) using EWSR1 breakapart probes was negative and molecular study with RNA sequencing was required to confirm the diagnosis. These findings highlight the diagnostic challenge and potential pitfall of FISH study in EWSR1-PATZ1 sarcoma. Further studies are required to increase the understanding of their behavior, morphologic spectrum and molecular features that will help devise new treatment strategies to these rare tumours.

Spindle cell hemangioma in the infratemporal fossa: A unique case report

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Spindle cell hemangioma (SCH) is a rare vascular tumor that was considered to be intermediate -or low-grade malignancy, with biological behavior between a hemangioma and angiosarcoma.

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The SCH is commonly found in the distal extremities. So far, only 16 cases have been described in the head and neck area. No previous case has been described in the infratemporal fossa.

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SCH shows a proliferation of spindle cells composed of endothelial cells, pericytes and fibroblasts between dilated vascular spaces and immunoreactivity to endothelial markers.

Introduction

Spindle cell hemangioma (SCH) is a rare vascular tumor which was first described in 1986. It affects mostly the distal extremities. The head and neck are rarely involved. This article reports the first case of SCH in the infratemporal fossa.

Presentation of case

A 41-year-old woman presented with an 8-month history of right cheek swelling. Facial CT scan and MRI showed an intensely and heterogeneously enhancing tumor of the infratemporal fossa suggesting an angiomatous neoplasm. The mass was excised surgically through an anterior maxillary approach. The histopathological and immunohistochemistry analysis revealed a SCH.

Conclusion

This case report presents a unique presentation of a Spindle cell hemangioma in an unexpected location of the head and neck region. it underlines the importance for clinicians and pathologists to consider the Spindle cell hemangioma as a possible etiological diagnosis of infratemporal fossa tumors.

Challenges in the Diagnosis of Pediatric Spindle Cell/Sclerosing Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma, representing approximately 40% of all pediatric soft tissue sarcomas. The spindle cell/sclerosing subtype of RMS (SSRMS) accounts for roughly 5% to 10% of all cases of adult and pediatric RMS. Historically, SSRMS were described as paratesticular tumors with an excellent outcome. However, more recent studies have identified unique molecular subgroups of SSRMS, including those with MYOD1 mutations or VGLL2/NCOA2 fusions, which have widely disparate outcomes. The goal of this article is to better describe the biological heterogeneity of SSRMS, which may allow the pathologist to provide important prognostic information.

Inflammatory myofibroblastic tumor of the urinary bladder: A prognostically favorable spindle cell neoplasm

Inflammatory myofibroblastic tumor (IMT) is a rare, benign spindle cell neoplasm of the urinary bladder with a presentation concerning a malignant disease. Oftentimes, these tumors pose a diagnostic dilemma because of a significant overlap with malignant spindle cell tumors in terms of clinical presentation, gross findings, and immunohistopathologic profile. A 28-year-old female presented to us with gross hematuria. Upon work up, the presence of a bladder mass was noted. Cystoscopy and transurethral resection of bladder tumor were done and histopathologic results revealed an IMT. Partial cystectomy was then performed for complete surgical resection.

Primary undifferentiated spindle cell sarcoma obstructing the right ventricular outflow tract

Background

Primary undifferentiated spindle cell sarcoma in the right ventricle is an extremely rare tumor. Radical surgical excision is the optimal treatment for long-term survival due to poor response to chemotherapy or radiotherapy at an advanced stage.

Case presentation

A 42-year-old man with no previous medical history presented with mild dyspnea on exertion and abdominal distension that lasted a week. Computed tomography (CT) revealed a huge homogeneous mass completely obstructing the right ventricle and extending into the pulmonary trunk. However, he suddenly collapsed the next day while on his way to an echocardiography. An extracorporeal membrane oxygenation (ECMO) device was inserted percutaneously and ECMO support was urgently initiated. Based on consideration of right ventricular outflow tract (RVOT) obstruction in the initial CT scan, we decided to remove the mass from the right ventricle immediately. The main mass was resected to relieve the RVOT obstruction, and after the operation, the ECMO was removed from the operation room. However, the patient failed to regain consciousness and electroencephalography (EEG) and subsequent magnetic resonance imaging (MRI) indicated severe hypoxic brain damage. We assume CPR was unsuccessful because the mass completely blocked the RVOT. Pathology revealed the mass was an undifferentiated spindle cell sarcoma.

Conclusions

We present the case of a 42-year-old male with cardiac arrest due to right ventricular outflow tract obstruction by a tumor of the right ventricle. Surgical resection was performed and in histopathology it was proved to be an undifferentiated spindle cell sarcoma.

A rare case of intranodal hemorrhagic spindle cell tumor with amianthoid fibers presenting as a suspicious lump in the groin

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Hemorrhagic spindle cell tumor with amianthoid fibers is extremely rare.

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The present case adds to the very limited data available on this entity.

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The tumor in the present case reached a relatively large size and raised clinical suspicion for lymphoma.

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This tumor is a mimicker for many benign and malignant conditions.

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This tumor must be considered to avoid the misinterpretation as primary malignant spindle cell lesion or metastasis.

Introduction

Intranodal hemorrhagic spindle cell tumor with amianthoid fibers is extremely rare.

Presentation of the case

Herein, we present the case of a 58-year-old man with a 2-year history of painless left inguinal swelling. On physical examination, the mass was large, fixed, hard, and non-tender, suggesting a lymph node pathology. The mass had increased slightly in size after a short course of antibiotic treatment. The surgeon decided to perform an excisional biopsy of the left inguinal lymph node. The lesion was intraoperatively hard and suspicious for malignancy. The gross examination revealed a relatively large well-circumscribed mass with a whitish, hard, cut surface. The histomorphological and immunohistochemical findings were consistent with intranodal hemorrhagic spindle cell tumor with amianthoid fibers. There was no evidence of recurrence at 4 years post surgery.

Discussion

The present case adds to the very limited data available on this rare entity.

Conclusion

Intranodal hemorrhagic spindle cell tumor with amianthoid fibers can be a diagnostic pitfall both clinically and histopathologically. It can reach large sizes and be clinically and grossly suspicious for lymphoma. Clinicians must be made aware that such an entity exists.

Adenoid cystic carcinoma with high-grade transformation forming spindle cell component of the submandibular gland

Adenoid cystic carcinoma (AdCC) with high-grade transformation (AdCC-HGT) is rare, and AdCC-HGT with spindle cell component is particularly rare. The patient was a 65-year-old man with a 5 cm sized swelling of the right submandibular gland. Submandibular sialoadenectomy was performed. Histopathological findings mainly showed conventional AdCC, and minorly showed two other components: (1) the pleomorphic component, a proliferation of atypical pleomorphic epithelial cells forming solid or small clusters and accompanied by necrosis; (2) the spindle cell component, containing atypical spindle cells invading the stroma. Postoperative chemoradiotherapy was performed. Multiple right lung nodular lesions were found on the contrast-enhanced chest CT one month after the surgery. Thoracoscopic pulmonary resection was performed. The lung tumors exhibited a proliferation of atypical spindle cells, accompanied by necrosis. We considered that the spindle cell component of the AdCC-HGT of the submandibular gland developed lung metastases. The patient died seven months after submandibular sialoadenectomy due to respiratory failure. Although rare, our case highlights the importance of recognising spindle cell components in conventional AdCC; even if the area is small, these high-grade transformation areas can metastasise and become prognostic factors.

Sarcomatoid carcinoma of the pancreas: A case report

BACKGROUND

Sarcomatoid carcinoma of the pancreas (SCP) is a rare and aggressive epithelial tumor that has both epithelial and mesenchymal features. It is characterized by sarcomatous elements with evidence of epithelial differentiation. And the term “sarcomatoid carcinoma” is often confused with “carcinosarcoma”.

CASE SUMMARY

We present a case of SCP with lymph node metastasis in a 59-year-old male patient. He had experienced darkening of the urine, scleral icterus, and fatigue for 4 weeks. Computed tomography and magnetic resonance imaging revealed a mass in the pancreatic head, and laboratory tests revealed elevated serum bilirubin levels. The patient underwent pancreaticoduodenectomy after biliary decompression. Histologically, spindle cells with marked nuclear atypia and brisk mitotic activity arranged in a storiform or fascicular pattern were present in the bulk of the tumor. Immunohistochemical analysis found that the spindle cells exhibited strong diffuse positivity for epithelial markers, indicative of epithelial differentiation. Accordingly, the pathologic diagnosis of the pancreatic neoplasm was SCP.

CONCLUSION

Although sarcomatoid carcinomas and carcinosarcomas have different pathologic features, both have epithelial origin.

Computed tomography imaging characteristics of primary atrial intimal sarcoma

We present a 36-year-old man who presented to our emergency department with acute onset shortness of breath and syncope. He was found to have a large left atrial mass on initial computed tomography (CT) which was confirmed by echocardiography. Tumor biopsy and attempted excision were performed, showing a primary cardiac spindle cell sarcoma that was unable to be resected, to which the patient eventually succumbed to. Spindle cell sarcomas of the heart are very rare primary cardiac tumors, with a variable, non-specific presentation. The most effective treatment is surgical resection, with chemotherapy and radiotherapy showing some benefit. Despite these treatments, the prognosis is poor. Given the uncommon nature of this tumor, the objective of this report is to demonstrate the clinical presentation and CT imaging characteristics of a case of primary cardiac spindle cell sarcoma, to raise awareness of this entity, and to increase the index of suspicion as a potential differential diagnosis to cardiac tumors seen on imaging.

Clinical epidemiology and treatment outcomes of spindle cell non-osteogenic bone sarcomas - A nationwide population-based study

Purpose

To describe epidemiological and clinical characteristics, as well as long-term treatment outcomes of spindle cell non-osteogenic bone sarcomas (SCS), comprising leiomyosarcoma, fibrosarcoma and undifferentiated pleomorphic sarcoma in bone.

Method

We have analysed a nationwide cohort of 104 patients with histologically verified SCS diagnosed between 1975 and 2009, based on registry sources supplemented with clinical records from Norwegian hospitals involved in sarcoma management.

Results

In this unselected cohort, a stable annual incidence for SCS patients of slightly below 0.6 per million was observed, with a dominant peak among elderly patients. SCS is mostly a high-grade malignancy (92%) with a male to female ratio of 1.6 for all patients. The axial to appendicular ratio was 0.7, seemingly independent of age. More than one fourth of the patients (29%) had primary metastatic disease. Another 32 patients (46%) developed metastases during follow-up and 12 (17%) experienced local relapses. The five-year sarcoma-specific survival rate was 37%, with no documented improvement over time. Primary metastatic disease was an adverse prognostic factor for survival. Predisposing factors were documented in 19 patients (18%). Negative prognostic factors for overall survival were tumour size >9 cm, age > 40 years, axial tumour localization, FS as subtype and pathologic fracture at time of diagnoses. As expected, patients who received both surgery and chemotherapy as their primary treatment for high-grade SCS (25%) significantly had best sarcoma specific five years survival (62%).

Conclusion

We confirm SCS as a rare high-grade bone sarcoma entity, mostly among elderly patients and with a poor overall outcome. The combined treatment of surgery and chemotherapy is essential to achieve optimal long-term survival of SCS.

Laryngeal Basaloid Squamous Cell Carcinoma with a Substantial Spindle Cell Component: Case Presentation and Updated Review of Literature

Basaloid squamous cell carcinoma with spindle cell component is an uncommon aggressive variety of squamous cell carcinoma with only a few reported cases in literature. Histologically a combination of basaloid squamous cell carcinoma and spindle cell squamous cell carcinoma is appreciated and immunohistochemistry serves a role in differentiation from malignant neoplasms of salivary gland or neuro-endocrine origin. Prime treatment modality is combination of surgery and external beam radiotherapy. A case of basaloid squamous cell carcinoma with proliferation of bizarre mesenchymal component is being reported here with an updated literature review.

Matricellular CCN6 (WISP3) protein: a tumor suppressor for mammary metaplastic carcinomas

Located at 6q22-23, Ccn6 (WISP3) encodes for a matrix-associated protein of the CCN family, characterized by regulatory, rather than structural, roles in development and cancer. CCN6, the least studied member of the CCN family, shares the conserved multimodular structure of CCN proteins, as well as their tissue and cell-type specific functions. In the breast, CCN6 is a critical regulator of epithelial-to-mesenchymal transitions (EMT) and tumor initiating cells. Studies using human breast cancer tissue samples demonstrated that CCN6 messenger RNA and protein are expressed in normal breast epithelia but reduced or lost in aggressive breast cancer phenotypes, especially inflammatory breast cancer and metaplastic carcinomas. Metaplastic carcinomas are mesenchymal-like triple negative breast carcinomas, enriched for markers of EMT and stemness. RNAseq analyses of the TCGA Breast Cancer cohort show reduced CCN6 expression in approximately 50% of metaplastic carcinomas compared to normal breast. Our group identified frameshift mutations of Ccn6 in a subset of human metaplastic breast carcinoma. Importantly, conditional, mammary epithelial-cell specific ccn6 (wisp3) knockout mice develop invasive high-grade mammary carcinomas that recapitulate human spindle cell metaplastic carcinomas, demonstrating a tumor suppressor function for ccn6. Our studies on CCN6 functions in metaplastic carcinoma highlight the potential of CCN6 as a novel therapeutic approach for this specific type of breast cancer.

Myxoid Solitary Fibrous Tumor on the Scalp

Myxoid solitary fibrous tumor (SFT) is very rare soft tissue neoplasm. It is microscopically composed of spindle cells which is individually separated by delicate band of collagen fibers. And this tumor cells are immunohisto-chemistrically highlighted by CD34. Myxoid SFT has indolent clinical course and a good prognosis, so it is important to make a diagnosis because of its morphological similarities to myxoid spindle cell neoplasms that have different prognoses and treatment. We report the case of a 20-year-old female with a myxoid SFT found in the left temporo-parietal scalp. This case report appears to be the first reported scalp occurrence of this rare tumor.

[Sarcomatoid carcinoma of larynx. A histological challenge?]

INTRODUCTION

Sarcomatoid carcinoma can occur in any part of the body; in the head and neck it occurs most frequently in the major salivary glands, with only about 1% of cases found in the larynx. As it has both epithelial and mesenchymal components, there are many theories concerning its origin and it can prove a diagnostic challenge.

CASE REPORT

A 76 year old male smoker presented with dysphonia. Vocal cord injury was found on examination but no lymphadenopathy or metastases were present. Laryngeal microsurgery was performed with complete excision of the lesion. Histopathology showed it to be a carcinosarcoma which showed intense and diffuse positivity for vimentin and focal positivity for AE1-AE3, CK5 and p63. The patient underwent radiotherapy as complementary treatment.

DISCUSSION

Sarcomatoid carcinoma usually presents with obstructive symptoms such as dysphonia. Prognosis depends on the stage and the presence or not of metastases. Both epithelial markers EMA, cytokeratin (AE1-AE3), epithelial membrane antigen, Ki 67 and mesenchymal markers such as vimentin, desmin, S-100 may be positive in these tumours. Recommended treatment for T2-T1 stages is an excisional biopsy which can be followed by adjuvant radiotherapy; radiotherapy alone has also been successful. T3-T4 stages can be treated with local excision, partial laryngectomy or total laryngectomy with subsequent ganglion emptying and concomitant radio and chemotherapy.

Combined classical spindle cell/pleomorphic lipoma spectrum imaging and clinical data

OBJECTIVES

Compile the largest study to date on the imaging and clinical features of the classic spindle cell/pleomorphic lipoma spectrum and suggest this diagnosis be included in the differential for benign and malignant macroscopic fat-containing soft tissue masses regardless of the mass location or patient demographics.

MATERIALS AND METHODS

An institutional search was performed to identify all available classic-type spindle cell/pleomorphic lipomas with available demographic and imaging data. Images and reports were analyzed by one MSK-trained radiologist and radiographic, anatomic and clinical data were recorded. Additionally, a literature search was performed to identify studies describing the spindle cell lipoma spectrum imaging features and were combined with institutional data.

RESULTS

Forty-two institutional cases were identified, 37 of which had MRIs performed among which 21 had images available (T1- and T2-weighted pulse sequences) for review while the remainder had outside reports detailing the mass imaging features. There was a mean age of 57 with 79% of cases occurring in males. Contrary to prior reports, 57% of masses were subcutaneous, and the neck and back region accounted for 26% of cases. When the institutional cases were combined with available data in the literature, there was a new sample size of 91 masses, 74 of which had MRI and/or CT data. Eighty-seven percent of masses were heterogeneous, 51% were composed of less than 75% fat, 65% were in the back, neck or shoulder region, 27% of masses were deep and 91% demonstrated enhancement. Eighty-two percent of patients were males with a mean age of 58 at excision.

CONCLUSION

Imaging features, patient demographics and tumor location alone are not enough to differentiate tumors of the spindle cell lipoma spectrum from other macroscopic fat-containing benign and malignant tumors, and these entities should be included in the same imaging differential diagnosis.

Tubercular Mycobacterial Spindle Cell Pseudotumour: A Case Report

Pseudotumour is a benign inflammatory lesion. Mycobacterial spindle cell pseudotumour (MSP) is a rare pseudotumour. It is a benign proliferation of spindle-shaped histiocytes containing acid-fast mycobacterium, commonly reported in immunocompromised patients. MSP is usually associated with mycobacterium avium complex (MAC). Here, we present the case of a 38-year-old gentleman with acquired immune deficiency syndrome (AIDS) who presented with low-grade fever for 1-month duration. Clinically, he had generalised lymphadenopathy. Chest X-ray showed miliary infiltration in bilateral lung fields. Lymph nodal biopsy showed spindle-shaped histiocytes filled with acid-fast bacilli on Ziehl-Neelsen (ZN) stain, suggestive of MSP. Immunohistochemical (IHC) stains were positive for CD68, S-100 and negative for CD31, which are consistent with MSP. Polymerase chain reaction (PCR) of the biopsy tissue was positive for MTB. Highly active antiretroviral therapy (HAART) was continued and anti-tubercular therapy (ATT) was started. The fever resolved within two weeks and there was a resolution of lymph nodal swelling by 6 weeks. The diagnosis of MSP associated with mycobacterium tuberculosis (MTB) makes our case interesting. It is of utmost importance to differentiate MSP from Kaposi's sarcoma (KS) and other pseudotumours and to know whether it is of tubercular or non-tubercular origin, as the treatment is entirely different.

Spontaneous splenic artery rupture in a patient with an unclassified malignant spindle cell tumor of the spleen: report of a case

The purpose of this paper was to describe an unusual manifestation of a sarcoma of the spleen and to raise awareness for spontaneous rupture of the splenic vessels in patients with splenic tumors. A 70-year-old man was admitted to our institution, suffering from left upper quadrant abdominal pain. Upon physical examination, a large and tender abdominal mass was palpated. Abdominal computed tomography showed a heterogenous enlarged spleen with active contrast extravasation from the splenic artery, free intraperitoneal fluid, and a retroperitoneal hematoma. The patient was treated with angioembolization of the splenic artery. Because of rebleeding, splenectomy was performed. Pathology revealed the spleen to be involved with an unclassified malignant spindle cell neoplasm. We concluded that in the case of spontaneous rupture of the splenic artery, accompanied with a radiologic appearance of an enlarged spleen, the diagnosis of sarcoma should be included in the differential diagnosis.

Lipoblasts in spindle cell and pleomorphic lipomas: a close scrutiny

The presence and frequency of lipoblasts (LPB) in spindle cell lipomas (SCL) and pleomorphic lipomas (PL) has never been studied in detail on a histologically, immunohistochemically and molecular genetically validated set of tumors. The authors investigated this feature by reviewing 91 cases of SCL and 38 PL. When more than 3 unequivocal LPB were found, the case was regarded as positive for the presence of LPB. All positive cases were then stained with CD34 and retinoblastoma (Rb) protein antibodies and tested by fluorescence in situ hybridization for MDM2 and CDK4 amplifications and the FUS gene rearrangements. The patients with SCL and PL containing LPB were 14 women and 47 men, the rest were of unknown gender. The cases usually presented as superficial, well-circumscribed soft tissue masses and most commonly occurred in the upper back and neck. CD34 was expressed in all cases, while Rb protein was consistently absent in all. Molecular genetic results, when available, were in concordance with the morphological diagnosis of SCL/PL. LPB were found in 37 (41%) cases of SCL and 25 cases of PL (66%). While in many cases they are inconspicuous, in some others they constitute a very prominent component of the tumor. It is important to be aware of this fact in order to avoid misinterpretation as liposarcoma.

Rhabdomyosarcoma, Spindle Cell/Sclerosing Variant: A Clinical and Histopathological Examination of this Rare Variant with Three New Cases from the Oral Cavity

Spindle cell/sclerosing rhabdomyosarcoma (S-ScRMS) was recently recognized in 2013 by the World Health Organization (WHO) as a stand-alone entity (Parham et al., WHO classification of tumours of soft tissue and bone, IARC Press, Lyon, 2013). Historically, the spindle cell and sclerosing variants were subcategorized under embryonal type rhabdomyosarcoma. Current data supports that certain S-ScRMS cases have a more aggressive clinical course with reduction of long-term survival, and those found in the head and neck region often exhibit extensive local recurrence. Furthermore, due to variable histopathologic appearances and immunohistochemical findings, misdiagnosis is common. We aim to report the variability in histopathologic patterns, immunohistochemical findings, radiographic features, and clinical data on three new cases of S-ScRMS presenting in the oral cavity of young adult males (ages 22, 24, and 39 years). The English-language literature on S-ScRMS is briefly reviewed as well.

Endobronchial neurogenic tumor: A combination of traumatic neuroma and neurofibroma

Traumatic neuromas are uncommon and benign lesions arising from a peripheral nerve injury during surgery. Here we describe a case with histopathologic features of both a traumatic neuroma and neurofibroma in a patient without integumentary physical exam findings nor prior surgical history. A 54 year old male was admitted for surgical debridement of a foot ulcer. During pre-operative evaluation and review of imaging multiple CT scans revealed a stable, 4 mm endobronchial lesion in the left lower lobe. Given history of nicotine abuse, bronchoscopy was performed. Bronchoscopy showed a pearly, polypoid lesion. Histopathological results showed strong positivity for S-100 protein and spindle cell proliferation. Repeat CT chest showed no new lesions in the bronchial tree. The rarity of this case is noted not only by the limited number of bronchial neurogenic tumors, but the combined features in this case of a traumatic neuroma and neurofibroma which has not been described.

Spindle cell sarcomatoid carcinoma of the trachea: first case report of surgical resection

BACKGROUND

Primary malignant tracheal tumors are rare, accounting for approximately 0.2 % of respiratory tract tumors yearly, with squamous cell carcinomas and adenoid cystic carcinomas accounting for two-thirds of these cases. Sarcomatoid carcinomas are a group of poorly differentiated non-small cell lung carcinomas containing a component of sarcoma or sarcoma-like (spindle and/or giant cell) differentiation, categorized into five morphologic subgroups. Spindle cell sarcomatoid carcinoma is a rare variant of sarcomatoid carcinomas, consisting of only spindle-shaped tumor cells. Only one other case has been reported as a primary tracheal tumor.

CASE PRESENTATION

We present a 75-year-old male, having progressive dyspnea and cough, with a spindle cell sarcomatoid carcinoma tumor visualized on chest computed tomography scan and confirmed with biopsy.

CONCLUSIONS

Due to its low incidence, knowledge of treatment methods, prognostic factors, and etiology is limited thus approaches to eradication have widely varied. We are reporting the second published case of spindle cell sarcomatoid carcinoma of the trachea and the first reported successful outcome of definitive treatment with tracheal resection.

Keloidal Atypical Fibroxanthoma: Case and Review of the Literature

Keloidal atypical fibroxanthoma (KAF) has recently been categorized as a variant of atypical fibroxanthoma. This paper will emphasize the importance of including KAF in both clinical and histological differential diagnosis of benign and malignant lesions which exhibit keloidal collagen and will also review the current literature on epidemiology, pathogenesis, histology, immunochemistry and treatments.

Diagnostically Challenging Spindle Cell Neoplasms of the Retroperitoneum

The diagnostic spectrum of spindle cell neoplasms arising in the retroperitoneum is wide and, in the presence of commonly shared morphologic features, it may be challenging to establish a correct diagnosis in certain cases. Beyond seemingly undifferentiated spindle cell morphology, most neoplasms may reveal distinctive adipocytic, smooth muscle or myofibroblastic or nerve sheath differentiation and show additional diagnostic clues or characteristic molecular abnormalities. Obtaining sufficient and representative biopsy material, a thorough work-up, and extensive sampling of gross specimens followed by a combined histopathologic, immunohistochemical, and, if necessary, molecular work-up of these cases is advisable so as not to miss important diagnostic and/or prognostic indicators.

Extranodal B Cell Lymphoma with Prominent Spindle Cell Features Arising in Uterus and in Maxillary Sinus: Report of Two Cases and Literature Review

Primary B-cell lymphoma exhibiting a spindle dominant pattern is extremely rare and represents a potential diagnostic pitfall. Here we report two cases of extranodal B cell lymphoma with spindle cell dominant morphology (sp-BCL) of uterus and maxillary sinus. Case 1 was a 54-year-old female with a large mass in the lower uterine segment, inseparable from the wall of the rectum and the urinary bladder. This is the first report of primary sp-BCL arising in the lower uterine segment. Case 2 was a 54-year-old male with a permeative mass involving the maxillary sinus wall with extension into the premaxillary soft tissues. Biopsies of both cases revealed a diffuse infiltration by medium to large atypical spindle cells. A panel of immunohistochemical stains was performed to rule out the possibilities of sarcoma, carcinoma, or melanoma. The final diagnosis was diffuse large B cell lymphoma, germinal center type. This is the first report of sp-BCL incorporating molecular genetic studies and the next-generation sequencing analysis performed on the maxillary lymphoma revealed three genomic alterations in genes of EZH2 (Y646N), IRF8 (S55A), and TNFRSF14 (splice site 304+2T>C). These genes were reported to play important roles in the pathogenesis of diffuse large B cell lymphoma. Both patients achieved complete remission after excision and chemo-radiation therapy despite the extensive local involvement.

Step by step approach to rare breast lesions containing spindle cells

Differential diagnosis of spindle cell lesions of breast is challenging for certain reasons. The most important reason is the presence of cytological atypia and mitosis in all three conditions: reactive, benign, and malignant. Patients diagnosed with benign and malignant tumor/tumor-like lesions that had spindle cell components following the histopathological examination were included in the study. The patients’ medical records were accessed to obtain the clinical history, follow-up notes, and radiological findings. Following histopathological, immunohistochemical, and clinical evaluations, the patients were diagnosed as follows: pseudoangiomatous stromal hyperplasia (PASH), bilateral desmoid-type fibromatosis (FM), adenomyoepithelioma (AME), myofibroblastoma (MFB), malignant phyllodes tumor (MF), high-grade AS, post-chemotherapy osteosarcoma (OS) + Paget’s disease, and metaplastic carcinoma (MC). An algorithmic approach should be used in the diagnosis; cellular structure, presence and grade of atypia, growth pattern, mitotic activity, immunohistochemical staining, and clinical and radiological features should be evaluated together. Detection of some molecular changes can be useful in differential diagnosis.

Spindle cell carcinoma of the mandible: Clinicopathological and immunohistochemical characteristics

Spindle cell carcinoma, a rare variant of squamous cell carcinoma, has propensity to occur in the upper aero digestive tract, including the oral mucosa. In this oral pathology communication, we report the occurrence of this neoplasm in the left mandible as a large fleshy growth with destruction of bone in a 73-year-old Afro-Trinidadian female. The distinction of this tumor from other malignant spindle cell mesenchymal tumors is important. Selective sampling of this specimen for possible transitional areas of squamous and spindle cell appearance, immunohistochemical staining for cytokeratin, vimentin, and S-100 protein are helpful in establishing the diagnosis. According to the patient's insistence, debulking of the tumor was performed under general anesthesia. Eight months later the patient succumbed to the disease.

A rare case of a myofibroma presenting on the tongue

Myofibromas are benign neoplasms of myofibroblastic origin, rarely encountered in the oral cavity. Limited awareness of the clinical features of these lesions risks misdiagnosis of more sinister pathology. The objective of this report is to highlight the potential diversity of oral lesions by describing an uncommon presentation of a myofibroma. The case reveals the diagnostic difficulties encountered, along with postoperative complications, which exemplify the remarkable healing capacity of the oral cavity.

An Adult Case of Paratesticular Spindle Cell Rhabdomyosarcoma

Paratesticular rhabdomyosarcoma (RMS) occurs more frequently in children and is rare in adults. Embryonal RMS is the most common subtype of paratesticular RMS. Spindle cell is a rare variant of embryonal RMS and is associated with a favorable prognosis in children. Data in adults is lacking. We present a case of paratesticular RMS in a 24-year-old man.

Primary platelet-derived growth factor-producing, spindle-shaped diffuse large B-cell lymphoma of the skull: a case report and literature review

A 39-year-old woman with a right frontal mass underwent a cranial bone tumor biopsy. Histopathologic examination of hematoxylin and eosin-stained slides showed spindle-shaped tumor cells in a storiform pattern, appearing somewhat like a sarcoma. However, the tumor cells were CD20-positive by immunohistochemical staining. Therefore, a diagnosis of spindle-shaped diffuse large B-cell lymphoma (Sp-DLBCL) was made. There have been at least 35 cases of Sp-DLBCL documented in the literature, and most were of the germinal center type, while the present case is the first report of a vimentin-positive primary Sp-DLBCL of the skull. The DLBCL in this case was immunohistochemically stained for six representative cytokines that might give rise to fibrosis, due to the evidence of fibroblastic proliferation. The DLBCL cells were positive for platelet-derived growth factor (PDGF), and some cells were also positive for tumor necrosis factor (TNF) α. Based on these findings, it was inferred that the PDGF and TNFα produced by DLBCL cells induced fibroblastic proliferation. The resultant conspicuous fibrosis caused interfibrous impingement on the DLBCL cells, which deformed them into a spindle shape. The present case is the first reported case of a PDGF-producing Sp-DLBCL.