scholarly journals Inflammatory fibroid polyp: an immunohistochemical study

2004 ◽  
Vol 41 (2) ◽  
pp. 104-107 ◽  
Author(s):  
Gilda da Cunha Santos ◽  
Venâncio A.F. Alves ◽  
Alda Wakamatsu ◽  
Sérgio Zucoloto

BACKGROUND: Inflammatory fibroid polyp is a localized lesion, which arises in the submucosa of the gastrointestinal tract, most often in the stomach.Although it is generally believed to represent a reactive, nonneoplastic condition, its histogenesis remains controversial. AIM: To study inflammatory fibroid polyp by immunohistochemistry in an attempt to further clarify their histogenesis. MATERIAL AND METHODS: Nine cases were studied by immunohistochemistry using a panel of antibodies against smooth-muscle actin, vimentin, S-100 protein, factor VIII- R.Ag and macrophage (HAM-56). RESULTS: There was a strong diffuse positive staining pattern in the spindle cells with vimentin antibody. A patchy staining for smooth-muscle actin was observed in these cells. Immunophenotyping revealed a heterogeneous reaction with HAM-56. In edematous areas, HAM-56-positive cells show voluminous cytoplasm and reniform nuclei. In cell-rich areas, the HAM-56-positive cells had fusiform cytoplasm. Stains for S-100 and factor VIII RAg were negative in the proliferating elements. CONCLUSIONS: The present immunohistochemical study refutes the suggested neural or vascular nature of the lesion. The strong positivity for vimentin in all cases suggests a major component of spindle cells best recognizable as fibroblasts. These results would favor the existence of a span of morphological and immunohistochemical patterns possibly indicating evolutive phases of an inflammatory reaction.

Author(s):  
Luis Alberto Romano ◽  
Virgínia Fonseca Pedrosa

A capsulated nodular neoplasm measuring 9 cm in diameter, located between the swim bladder and the kidney sample of Cyprinuscarpio, was in laboratory. The neoplasm had a solid consistency in one sector and very adherent to the capsule. Histopathological examination of the neoplasm revealed a monotonous proliferation of spindle cells, and pleomorphic, sometimes in a vortex pattern and interspersed with collagen fibers. Cells had numerous well-oriented myofibrils giving them a deep red. The cytoplasm is eosinophilic and the nuclei are hyperchromatic located in the center with blunt or "cigar-shaped" ends. In the immunohistochemical examination, the tumor cells were positive for desmin, smooth muscle actin and K-47, the latter antibody showing significant cell proliferation. Due to histopathological and immunohistochemical findings, diagnosis was made with leiomyosarcoma.


2001 ◽  
Vol 125 (11) ◽  
pp. 1494-1496
Author(s):  
Ravindra Veeramachaneni ◽  
Janis Gulick ◽  
Ari O. Halldorsson ◽  
Thanh T. Van ◽  
Ping L. Zhang ◽  
...  

Abstract This report describes a benign myoepithelioma of the lung that occurred in a 60-year-old woman. The patient had experienced hoarseness for 6 weeks, and a computed tomographic scan showed a nodule of approximately 2 cm in diameter at the peripheral portion of her right upper lung. Positron emission tomography showed no uptake of F-18 fluorodeoxyglucose in the nodule. Wedge biopsy of the lesion showed benign spindle cells arranged in a whorled pattern. The cells were positive for both cytokeratin and smooth muscle actin, which corresponded to the presence of tonofilaments and myofilaments that were identified ultrastructurally. The features of the present case of benign myoepithelioma that differ from features of previously reported benign and malignant cases of myoepithelioma in the lung are discussed in the report.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2905 ◽  
Author(s):  
Sunil Munakomi ◽  
Pramod Chaudhary

Herein we report a rare case of a giant myopericytoma presenting in a 16-year-old girl as a slowly progressive swelling involving the scalp in the occipital region. It was managed by complete excision. Histological examination of the lesion revealed  spindle-shaped cells forming characteristic rosettes around the blood vessels, and positive staining with smooth muscle actin.


1991 ◽  
Vol 277 (3) ◽  
pp. 819-824 ◽  
Author(s):  
K Pritchard ◽  
S B Marston

1. We have investigated the ability of bovine brain S.100, and of three related proteins from sheep aorta smooth muscle, to confer Ca(2+)-sensitivity on thin filaments reconstituted from smooth-muscle actin, tropomyosin and caldesmon. 2. At 37 degrees C in pH 7.0 buffer containing 120 mM-KCl, approximately stoichiometric amounts of S.100 reversed caldesmon's inhibition of the activation of myosin MgATPase by smooth-muscle actin-tropomyosin. The [S.100] which reversed by 50% the inhibition by caldesmon (the E.C.50) was 2.5 microM when [caldesmon] = 2-3 microM in the assay mixture. When [KCl] was decreased to 70 mM, E.C.50 = 11.5 microM; at 25 degrees C in 70 mM-KCl, up to 20 microM-S.100 had no effect. When skeletal-muscle actin rather than smooth-muscle actin was used to reconstitute thin filaments, 20 microM-S.100 did reverse inhibition by caldesmon, at 25 degrees C in buffer containing 70 mM-KCl. This dependence on conditions is also characteristic of the calmodulin-caldesmon interaction. 3. These results suggested that S.100 or a related protein might interact with caldesmon in smooth muscle. We therefore attempted to prepare such a protein from sheep aorta. Three proteins were purified: an Mr-17,000 protein (yield 16 mg/kg), an abundant Mr-11,000 protein (yield 48 mg/kg), and an Mr-9000 protein (yield 4 mg/kg). Neither of the last two low-Mr proteins had any effect on activation of myosin MgATPase by reconstituted thin filaments. The protein of Mr 17,000 had Ca(2+)-sensitizing activity, and behaved exactly like brain calmodulin in the assay system.


2003 ◽  
Vol 40 (1) ◽  
pp. 42-54 ◽  
Author(s):  
D. Frost ◽  
J. Lasota ◽  
M. Miettinen

Fifty canine gastrointestinal (GI) mesenchymal tumors were examined to determine the occurrence of leiomyomas (LM) and GI stromal tumors and to compare their clinicopathologic features. Twenty-one tumors (42%) were histologically reclassified as gastrointestinal stromal tumors (GISTs) and 29 tumors (58%) as LMs on the basis of their histologic similarity with homologous human tumors. The GISTs occurred equally in males and females, with a mean age of 11 years (range 5–14 years). Five GISTs (24%) were associated with clinical signs and six (29%) had metastasis in liver or abdominal cavity. The GISTs occurred in large intestine (10, 48%), small bowel (six, 29%), stomach (four, 19%), and mesentery of small intestine (one, 5%). Histologically, they were highly cellular spindle, or less commonly epithelioid tumors with mitotic rates ranging from 0 to 19 per 10 HPF. Eleven tumors (52%) were positive for CD117 (KIT); seven (33%) were positive for smooth muscle actin but none for desmin and S-100 protein. Sequences of KIT exon 11, often mutated in human GISTs, were evaluated from four GISTs. Deletion of Try556-Lys557 coexisting with duplication of Gln555 in one case of GIST and T to C transition resulting in substitution of Pro for Leu575 in another were identified. The LMs occurred predominantly in males (82%) with a mean age of 11 years (range 8–17 years). Nine tumors (31%) had associated clinical signs. They occurred in the stomach (22, 76%), esophagus (four, 14%), and intestines (three, 10%); all were paucicellular, had no mitoses, and were composed of mature smooth muscle cells. Twenty-eight (97%) were positive for smooth muscle actin and 18(62%) for desmin but none for CD117 and S-100. Both GISTs and true LMs occur in the GI tract of dogs. Both tumors have distinctive pathologic features.


2002 ◽  
Vol 25 (2) ◽  
pp. 157-159 ◽  
Author(s):  
Luciana Corrêa ◽  
Mônica Lotufo ◽  
Marília Trierveiler Martins ◽  
Norberto Sugaya ◽  
Suzana Cantanhede Orsini Machado de Sousa

A case of unusual hamartoma in a six-year-old otherwise healthy Brazilian girl is reported, with emphasis on histological and immunohistochemical features. A mass observed in the incisive papilla was detected whose appearance was similar to congenital epulis or fibroma. Histological findings showed interlacing fascicles of large spindle cells resembling smooth muscle cells. Immunohistochemical staining for desmin and for smooth-muscle actin was positive. The histological diagnosis was leiomyomatous hamartoma, based on clinical and microscopic observations.


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