Malignant gastrointestinal neuroectodermal tumor: A case-based review of literature.

Malignant gastrointestinal (GI) neuroectodermal tumor is an extremely rare entity that was first described by Zambrano et al. in 2003 as "clear cell sarcoma (CCS)-like tumor of the GI tract." It shares some of the histopathological features of CCS but lacks the immunohistochemical (IHC) reactivity for melanocytic markers. Most mesenchymal neoplasms of the GI tract belong to the category of GI stromal tumors and are characterized by the IHC expression of c-KIT. In cases, without detectable KIT receptor expression, several differential diagnoses have to be taken into consideration. In this article, we describe such a case and present a review of all the reported cases till date. We also present the current available knowledge on its pathology and molecular genetics along with the limitations in its diagnosis. Here, we report a case of a 32-year-old man with a tumor of the small bowel composed of polygonal tumor cells arranged in solid nests, alveolar pattern, and pseudopapillary and admixed with numerous osteoclast-like multinucleated giant cells. Immunohistochemically, the tumor cells strongly expressed S-100 protein only. HMB-45, melan-A, CD117, cytokeratin, desmin, smooth muscle actin, and CD-34 were absent. Ki-67 index was 15%. The diagnosis was further confirmed by fluorescence in situ hybridization (FISH) demonstrating the presence of EWSR1 (22q12) translocation. A final diagnosis of malignant gastroneuroectodermal tumor was rendered. The patient is disease-free for 20 months of postsurgery. The diagnosis of this entity should be considered in the presence of S-100-positivity and multinucleated osteoclastic giant cells and the absence of melanocytic differentiation in a tumor arising from GI tract. Further confirmation can be done by performing FISH analysis.

Cyclooxygenase 2 (Cox 2) Expression in Newly Diagnosed Plasma Cell Myeloma: A Clinicopathological and Immunohistochemical Study on 73 Cases from a Single Tertiary Care Center.

To study the cyclooxygenase 2 (Cox 2) expression in newly diagnosed plasma cell myeloma cases by immunohistochemistry (IHC) and correlate with clinicohematological characteristics. Immunohistochemical expression of Cox 2 on bone marrow trephine biopsy was studied in seventy-three newly diagnosed myeloma cases [56 males, 17 females, median age; 58 years (36-75)] and fifteen controls using SP21 clone antibody. A median immuno-score (proportion x intensity) stratified the entire cohort into low and high expressors. Cox 2 immunoexpression was compared and correlated with clinicolaboratory characteristics and marrow histomorphology and survival. Twenty one of 73 (38.7%) cases had a plasmablastic morphology whereas remainder fifty-two (61.3%) had a differentiated morphology. The Cox 2 expression was noted in 71/73 (97.2%) cases (median score = 127.3) and 15/15 (100%) controls. Low expressors was associated with higher circulating plasma cells, increased marrow tumor burden, blastic morphology, and lower proliferation index (p < 0.05) with a peculiar 'dot-block' cytoplasmic positivity (p < 0.001); whereas high expressors had thinned out bony trabeculae with granular cytoplasmic positivity with or without membrane accentuation (p < 0.001). Cox 2 expression had a weak negative correlation with tumor burden (r; -0.32, p = 0.01) and positive correlation with proliferation index (r; 0.29, p = 0.03). There was no statistically significant difference in the survival between low (n = 20) and high (n = 23) expressors (log rank p = 0.11). A high proportion of myeloma cells in our cohort expressed Cox 2 using SP21 clone; and this may have a role in futuristic research and therapy.

Acquired Pure Red Cell Aplasia Following Recombinant Erythropoietin (Darbepoetin-alfa) Therapy.

Acquired pure red cell aplasia (PRCA) following use of recombinant erythropoietin (rEPO) is distinctly rare and sporadically reported in the literature. We discuss a case of PRCA following the usage of rEPO (darbepoetin-α) during the management of anemia of chronic kidney disease in an elderly male subject with review of literature and a brief insight into proposed pathophysiologic mechanism, diagnosis, and management.

A Vasculitis-Associated Neuromuscular and Vascular Hamartoma Presenting as a Fatal Form of Abdominal Cocoon.

Neuromuscular and vascular hamartoma (NMVH), also known as neuromesenchymal hamartoma, is a rare hamartomatous condition of the intestine. It usually presents with submucosal humps protruding in the intestinal lumen causing obstructive features. The other clinical manifestations are hematochezia or melena and protein-losing enteropathy. The etiopathogenesis of these lesions is not well known, although an association with small bowel Cröhn's disease and diaphragm disease had been postulated, the latter related to chronic nonsteroidal anti-inflammatory drug intake. Only 24 cases of NMVH are reported in the English literature and all of them could be adequately cured by resection of the affected part of the bowel. Moreover, none of these cases presented with abdominal cocoon or showed any evidence of vasculitis. We describe a peculiar case of NMVH in a 45-year-old male who presented with abdominal cocoon with symptomatic recurrence and fatal outcome within a month of surgery. Histopathology revealed classical histomorphology of NMVH with evidence of vasculitis. This appears to be the first case of a fatal form of NMVH, presenting with abdominal cocoon and associated with vasculitis.