Inflammatory myoglandular polyp of the cecum: case report and review of literature

<p>Abstract</p> <p>Background</p> <p>Inflammatory myoglandular polyp (IMGP) is a rare non-neoplastic polyp of the large bowel, commonly with a distal localization (rectosigmoid), obscure in its pathogenesis. Up till now, 60 cases of IMGP have been described in the literature, but none located in the cecum.</p> <p>Case presentation</p> <p>We report a case of a 53-year-old man who was admitted to our hospital for further evaluation of positive fecal occult blood test associated to anemia. A colonoscopy identified a red, sessile, lobulated polyp of the cecum, 4.2 cm in diameter, partially ulcerated. The histological examination of the biopsy revealed the presence of inflammatory granulation tissue with lymphocytic and eosinophil infiltration associated to a fibrous stroma: it was diagnosed as inflammatory fibroid polyp. Considering the polyp's features (absence of a peduncle and size) that could increase the risk of a polypectomy, a surgical resection was performed. Histological examination of the specimen revealed inflammatory granulation tissue in the lamina propria, hyperplastic glands with cystic dilatations, proliferation of smooth muscle and multiple erosions on the polyp surface: this polyp was finally diagnosed as IMGP. There was also another little polyp next to the ileocecal valve, not revealed at the colonoscopy, 0.8 cm in diameter, diagnosed as tubulovillous adenoma with low grade dysplasia.</p> <p>Conclusions</p> <p>This is the first case of IMGP of the cecum. It is a benign lesion of unknown pathogenesis and must be considered different from other non-neoplastic polyps of the large bowel such as inflammatory cap polyps (ICP), inflammatory cloacogenic polyps, juvenile polyps (JP), inflammatory fibroid polyps (IFP), polyps secondary to mucosal prolapse syndrome (MPS), polypoid prolapsing mucosal folds of diverticular disease. When symptomatic, IMGP should be removed endoscopically, whereas surgical resection is reserved only in selected patients as in our case.</p

Inflammatory fibroid polyp: an immunohistochemical study Pólipo inflamatório fibróide: estudo imunoistoquímico

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.<br>RACIONAL: O pólipo inflamatório fibróide é uma lesão localizada que se origina na submucosa do trato gastrointestinal, mais freqüentemente do estômago. Embora se acredite que represente condição reativa e não neoplásica, sua histogênese permanece controversa. OBJETIVO: Estudar o pólipo inflamatório fibróide por imunoistoquímica na tentativa de contribuir para o entendimento de sua histogênese. PACIENTES AND MÉTODOS: Foram estudados nove casos por imunoistoquímica usando-se um painel de anticorpos contra actina de músculo liso, vimentina, proteína S-100, fator VIII e macrófago (HAM-56). RESULTADOS: Houve um padrão difuso de coloração nas células fusiformes, fortemente positivo para vimentina. Um padrão focal de positividade para actina de músculo liso foi observado nessas células. O estudo revelou reação heterogênea com HAM-56. Nas áreas edematosas, as células positivas para HAM-56 mostraram citoplasma volumoso e núcleos reniformes. Nas áreas ricamente celulares, as células positivas para HAM-56 apresentaram citoplasma fusiforme. As reações para S-100 e fator VIII foram negativas nos elementos proliferantes. CONCLUSÕES: O presente estudo imunoistoquímico afasta a hipótese de natureza neural ou vascular da lesão. A forte positividade para vimentina em todos os casos sugere um componente principal de células fusiformes, melhor reconhecidas como fibroblastos. Estes resultados favoreceriam a existência de um espectro de padrões morfológicos e imunoistoquímicos, indicando, possivelmente, fases evolutivas de uma reação inflamatória