Pineal gland lesions: a cytopathologic study of 20 specimens.

Background: Pineal gland lesions are rare, with only a few cytologic descriptions occurring in the literature, according to the authors' knowledge. The current article describes the cytopathologic characteristics of 20 such lesions with discussion of differential diagnoses.

Methods: Cytologic material was obtained either by fine-needle aspiration biopsy (FNAB) under stearotactic radiologic guidance or by touch imprinting (TI) at the time of frozen sectioning.

Diagnosis of Wihipple disease by immunohistochemical analysis: a sensitive and specific method for the detection of Tropheryma whipplei (the Whipple bacillus) in paraffin-embedded tissue.

Whipple disease is a rare infection characterized clinically by diarrhea, fever, weight loss, arthralgia, malabsorption, and other systemic manifestations. The etiologic agent, Tropheryma whipplei, has been cultured only rarely. By using a polyclonal rabbit antibody produced against a cultured strain of T whipplei, tissue sections from 18 patients with Whipple disease were studied.

Fibromatosis of the breast and mutations involving the APC/beta-catenin pathway.

Fibromatoses of the breast are nonmetastasizing tumors, but can be infiltrative and locally recurrent. Breast fibromatoses are rare, and their specific genetic alterations have not been elucidated. However, their occasional occurrence in patients with familial adenomatous polyposis (FAP) and their morphologic identification with other deep fibromatoses (desmoid tumors) suggest that alterations of the APC/beta-catenin pathway might be involved in the pathogenesis of sporadic and FAP-associated breast fibromatoses.