Clinicopathological and molecular genomic features of monomorphic epitheliotropic intestinal T-cell lymphoma in the Chinese population: a study of 20 cases

Background Monomorphic epitheliotropic T-cell lymphoma (MEITL) is an aggressive non-Hodgkin lymphoma with a high fatality rate. This study was aimed to explore the clinicopathological and molecular genetic features of MEITL in the Chinese population. Methods A retrospective analysis was performed based on the clinical manifestations and pathological features of 20 Chinese MEITL. 9 cases with paired diseased-normal tissues were also analyzed for molecular information by whole-exome sequencing. Results There were 14 men and 6 women with a median age of 58.5 (28-81) years. 17(17/20) lesions were located in the jejunum or ileum; 13(13/20) cases had ulcers or perforations. Microscopically, except for 1(1/20) case of pleomorphic cells, the monomorphic, middle-sized tumor cells infiltrating into the intestinal epithelial and peripheral intestinal mucosa recess could be seen in the other 19 cases. Immunohistochemistry showed that most of the tumor cells in MEITL were positive for CD3(20/20), CD8(17/20), CD43(19/20), and CD56(15/20), but negative for CD5(20/20). The most frequently mutated genes of these Chinese cases were STAT5B (4/9) and TP53 (4/9), not SETD2(2/9). JAK3 mutations (3/9) were also detected with a high mutated frequency. We demonstrated that mutations of JAK-STAT pathway-related genes and the amplification of Chromosome 9q appeared at the same time in most cases(5/9). Conclusions The clinicopathological features were consistent with that in previous western studies, but a special case with pleomorphic cells was found in this study. The co-occurrence of JAK-STAT pathway-related gene mutations and the amplification of Chr9q is a molecular feature of MEITL.

Undifferentiated Pleomorphic Sarcoma of a Chronic Burn Scar of the Knee With Lymph Node Metastasis

Malignant transformation of chronic burn scars are usually toward cutaneous lineages, including squamous cell carcinoma, basal cell carcinoma, and malignant melanoma. Sarcomas are less common. Undifferentiated pleomorphic sarcoma(UPS) is a subtype of soft tissue sarcoma with storiform-pleomorphic cells of uncertain origin, and has sparingly been reported to arise from burn scars. The majority are localized lesions probably due to the spatial distance of mesenchymal cells from the epithelium. The authors describe a rare case of UPS of the chronic burn scar of his knee with ipsilateral femoral and external iliac lymph node metastasis.

Decoded: A Case Report on Dedifferentiated Liposarcoma on the Gluteal Area

Dedifferentiated liposarcoma is a soft tissue sarcoma of adipocytic lineage. Histopathology and immunohistochemistry are essential for diagnosis. A 51-year-old Filipino woman presented with a rapidly enlarging left gluteal tumor. Histopathology revealed a multilobulated tumor having prominent myxoid stroma with numerous stellate-shaped, atypical cells bearing atypical mitotic figures. Other lobules were composed of sheets of pleomorphic cells, with atypical mitotic figures. The tumor stained positively with alcian blue, vimentin, MDM2 and p16 stains. Other immunohistochemical (IHC) studies done (pancytokeratin, CK7, CK 20, CD 34, CEA, desmin, EMA, SMA, S100) showed negative results. After a 2 cm wide excision of the sarcoma, patient was free from local tumor recurrence for 2 months, after which she was lost to follow-up. We report this case and a brief review of the current literature on dedifferentiated liposarcoma.

Malignant Phyllodes Tumour with Rhabdomyosarcomatous Differentiation: A Rare Phenomenon

Phyllodes tumour is a rare tumour of the breast constituting less than 1% of all breast tumours. Malignant Phyllodes Tumour (MPT) accounts for only 10-30% of all phyllodes tumours. Heterologous sarcomatous differentiation in a MPT is an infrequent phenomenon, with the cases reported showing differentiation mostly towards liposarcoma, fibrosarcoma, angiosarcoma, osteosarcoma, or chondrosarcoma. MPTs with rhabdomyosarcomatous differentiation are scarcely seen with only three confirmed cases documented till date to the best of the knowledge after a thorough search of literature. Here, authors present a case of 45-year-old female who presented with a well-defined rapidly growing lump in the right breast for last one year. A core needle biopsy performed showed a sarcomatous picture on histology. Complete excision was subsequently done. On microscopy, most of the areas showed fibrosarcomatous changes with frequent mitoses. Some of the foci showed large pleomorphic cells in diffuse sheets that were polygonal with densely abundant eosinophilic cytoplasm and vesicular nucleus with prominent nucleoli (rhabdomyoblasts). Myogenin was diffusely positive on Immunohistochemistry (IHC). A diagnosis of MPT with rhabdomyosarcomatous differentiation was made. This case is reported here for its unusual presentation and to make pathologists aware of this rare heterologous differentiation of MPT.

A rare and overlooked cause of massive gastrointestinal bleeding: Distal duodenal GIST

Introduction. Gastrointestinal stromal tumors (GIST) are tumors of mesenchymal origin which originate from the walls of gastrointestinal system (GIS) organs. Aim. In this case report we aim to discuss the clinical, labaratory and radiological presentation of distal duodenal GIST as a rare and overlooked cause of life-threatining GIS bleeding. Description of the case. A 76-year-old male patient was presented to the emergency department with massive gastrointestinal bleeding. Computerized tomography revealed a mass soft tissue density of 4x4cm at the level of the 3-4th segment of the duodenum. At the endoscopy, there was a deep ulcer in the proximal part of the 3rd segment of the duodenum with a diameter of 2 cm with a bleeding vessel protruding into the lumen. After endoscopic treatments, biopsies were taken from the edges of the ulcer. Histopathological examination revealed a sheet-like infiltration composed of mildly pleomorphic cells with oval-spindle nuclei and abundant eosinophilic cytoplasm in the duodenal lamina propria, as the patient was diagnosed of GIST. Conclusion. GIST and its clinical, labaratory and radiological presentation should be kept in mind in the approach to massive duodenal GIS bleeding.

Malignant fibrous histiocytoma in a budgerigar (Melopsittacus undulatus)

In this report, a case of malignant fibrous histiocytoma in a budgerigar (Melopsittacus undulatus) is described. At necropsy, a tumorous subcutaneous mass was noted to be located under the right wing at the level of humerus in a budgerigar. On microscopic examination, the tumor was composed of pleomorphic cells having mostly round to oval large nucleus. Presence of occasional bands composed of fibroblastoid cells were noted. Occasional giant cells and mitotic figures were also observed. Based on the microscopic findings, a diagnosis of malignant fibrous histiocytoma was made. The present case in an exotic bird was found to be interesting, since malignant fibrous histiocytomas are rare tumors of domestic animals and mostly seen in dogs.

A Fatal Case of Pediatric Primary Myxoid Liposarcoma of the Orbit: A Rare Tumor in an Unusual Location Presenting with Widespread Metastasis

Introduction/Objective A liposarcoma is a tumor derived from primitive mesenchymal cells undergoing adipose differentiation. Liposarcomas are uncommon in childhood, representing only about 2% of childhood sarcomas. Among liposarcomas, is a very rare subtype, the so-called ‘pleomorphic myxoid liposarcoma’ which has extensive myxoid changes and scattered pleomorphic cells. Here we report an autopsy case of an extensively metastatic pleomorphic myxoid liposarcoma. Methods A 12 year-old, African-American boy presented in the ED with ascites and shortness of breath, who later expired despite resuscitation. Autopsy finding showed a primary lesion in the left superior orbital fissure with diffuse metastasis to liver, replacing most of the liver parenchyma (liver weigh 8500 g). Metastatic foci are also present in gallbladder, pancreas, large intestine, bilateral lungs, and inner and outer surfaces of cranium. Histologically, tumor at all sites shows similar morphology, revealing scattered pleomorphic lipoblasts and a myxoid background with arborizing vasculature. Lipoblasts show indented and distorted nuclei and cytoplasmic vacuoles. Immunohistochemically the tumor cells are immunoreactive for p16 (diffusely and strongly) (Figure, D) and S100 (weakly) and negative for AE1/AE3, myogenin, synaptophysin, GFAP, EMA, and CD34. FISH was negative for MDM2 and t(12;16)(q13;p11.2) FUS-DDIT3 rearrangement, ruling out conventional myxoid liposarcoma. Conclusion This case shows the aggressive nature of a poorly studied entity in an uncommon age group and emphasize the need to study childhood liposarcomas in more detail.

Extranodal lymphoma in a bush dog (Speothos venaticus) - case report

ABSTRACT A captive 7-year-old male bush dog (Speothos venaticus) was diagnosed with lymphoma affecting the kidneys, adrenal glands, liver, and spleen. The animal developed renal failure and was euthanized due to poor prognosis. Grossly, both kidneys were enlarged with multiple nodules. Histologically, the neoplasm was an infiltrative and poorly demarcated round cell tumor. Two morphologically distinct cell populations were observed, smaller cells with a lymphocytic morphology, and another population of larger and pleomorphic cells. Most of the smaller cell population, approximately 40% of the population within the neoplasm, were CD3 positive. Neoplastic cells were CD45, CD11d, and granzime B positive, and negative for CD20, CD79a, PAX5, CD163, and myeloperoxidase. This is the first reported case of lymphoma in a bush dog. This report demonstrated the suitability of several cell surface markers for differential diagnosis of round cell tumors in this species.