Mucosal atrophy in collagenous colitis: a case report.

BACKGROUND: Mucosal atrophy as a potential cause of impaired colonic compliance has not yet been described as a complication in Collagenous Colitis (CC). CASE PRESENTATION: We present a 51-year-old female patient with a 20-year history of diarrhea and diagnosed with CC ten years prior to her presentation. We reviewed reports from three colonoscopies performed after the diagnosis. Overall 12 biopsies obtained in the last two colonoscopies were re-analyzed by two pathologists blinded to the aim of the study. Besides the typical histological findings of CC, the endoscopic appearance was normal, and no histological signs of atrophy were found during the first colonoscopy. Surprisingly, the second and third colonoscopy revealed a region of advanced segmental mucosal atrophy in the cecum with the mucosal height normalizing toward the transverse colon. This pattern of atrophy was inversely related to the pattern of sub-epithelial collagen deposition, which increased toward the rectum. CONCLUSION: If no chance occurrence, our observation supports the idea that additional factors, probably luminal in nature, may be co-responsible for the mucosal atrophy in this case. Thus, mucosal atrophy in the proximal colon appears to be a new candidate among the growing list of rare complications associated with long standing CC.

Leiomyosarcoma of the larynx as a local relapse of squamous cell carcinoma--report of an unusual case.

BACKGROUND: The authors report on leiomyosarcoma after previously treated squamous cell carcinoma (SCC) at the glottis. METHODS: Primary tumor and relapses were investigated morphologically, immunohistochemically, and with molecular methods. RESULTS: The SCC was typical, but few cells showed a spindle-shaped pattern. The relapse tumor was a spindle-shaped and epitheloid tumor with the morphological and immunohistochemical appearance of leiomyosarcoma (sm-actin+, desmin+, caldesmon+, vimentin+, keratin-).The comparative genomic hybridization (CGH) revealed some gains and losses in the leiomyosarcoma. Because of altered material, the investigation failed in the primary. A fluorescence in situ hybridization (5p) focally detected 3 chromosmomal copies, corresponding to gains on 5p in CGH of leiomyosarcoma. CONCLUSION: Leiomyosarcoma after SCC is very uncommon. A connection between both seems likely in this case. Transdifferentiation, also seen in other tumors or carcinosarcomas, could be based on aberrant differentiation of a pluripotent stem cell.