Extracolonic gastrointestinal tract morphologic findings in a case of pseudomembranous collagenous colitis.

"Pseudomembranous collagenous colitis" is a morphologic variant of collagenous colitis in which active inflammation with pseudomembrane formation is prominent and which has been associated with infectious, toxic, and ischemic etiologies. However, extracolonic morphologic findings in patients with pseudomembranous collagenous colitis have not been previously described. Here, we present a case of a patient with pseudomembranous collagenous colitis with abnormal extracolonic findings. These include gastric antral mucosa with histologic features reminiscent of ischemic injury and reactive gastropathy with intraepithelial lymphocytosis and partial villous atrophy in the duodenal and ileal biopsies. The findings in the small intestinal biopsies resemble those seen in enteric mucosa in patients with conventional collagenous colitis. Our pathologic findings as well as the clinical course of the patient further emphasize the clinical and histologic similarities shared by pseudomembranous collagenous colitis and conventional collagenous colitis.

Cutaneous leiomyosarcoma originating in a symplastic pilar leiomyoma: a rare occurrence and potential diagnostic pitfall.

A case of cutaneous leiomyosarcoma originating in a symplastic pilar leiomyoma is described. The patient was a 60-year-old man who presented with a painless nodule on his chest. Thorough clinical examination did not reveal any evidence of tumor elsewhere. A punch biopsy was performed which showed a benign spindle cell neoplasm with focal cellular pleomorphism that had smooth muscle differentiation and was clearly originating from the arrector pili muscle, consistent with a cutaneous symplastic pilar leiomyoma. Immunohistochemical studies were performed and the tumor cells were strongly positive for smooth muscle actin (SMA) and desmin. Given the clinical information of a mass on the chest, clinical evaluation was recommended and a re-excision was performed. Histologically, the re-excision showed two distinct populations of cells. The upper portion of the tumor mirrored the initial biopsy; however, the base of the tumor showed hypercellular areas composed of spindle cells with marked pleomorphism and increased number of mitoses. The diagnosis of a cutaneous leiomyosarcoma originating in a symplastic pilar leiomyoma was given. This is the first report of this association of such occurrence reported in the literature.

Oncocytoma of the nasal cavity: A case report.

Oncocytomas arising in the nasal cavity are quite rare. These entities more commonly occur in the major salivary glands, minor salivary glands, respiratory seromucinous glands, and endocrine organs. Very few cases of oncocytoma in the nasal cavity have been reported, with only 5 diagnosed as malignant. This article describes a case involving an 81-year-old man with a nasal oncocytoma that was completely resected with an endoscopic medial maxillectomy. The diagnostic rationale is discussed, along with a review of the literature.