Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, ...

Cutaneous appendageal tumors are a large diverse group of tumors that are commonly classified according to their state of appendageal differentiationeccrine, apocrine, follicular and sebaceous. Most appendageal tumors are relatively uncommonly encountered in routine clinical practice. Though some of the appendageal tumors (e.g. syringoma, nevus sebaceous) can be diagnosed clinically with ease b...

Herein we describe a case of granular cell type trichoblastoma in a dog. A nine-year-old, intact male Scottish terrier presented with a solitary, exophytic and non-ulcerated nodule on the shoulder. Histopathologically, the nodule showed a ribbon-like structure, which was composed of branching cords of epithelial cells surrounded by fibrous stroma. In addition, islands of large clear cells were ...

INTRODUCTION Fibroepithelioma of Pinkus (FeP) is a rare tumor that most often affects women aged between 40 and 60 years. Clinically FeP presents as a soft, usually solitary, polypoid or papillomatous well circumscribed tumor of skin color. It is typically located to the trunk and extremities. CASE REPORT A 75 year old male presented to our Department complaining for the presence of a lesion ...

A 68-year-old Japanese man presented with a nodule that had been present for 5 to 6 years on the right side of the back. Physical examination revealed a dome-shaped, 12 x 13-mm, dark red nodule. It was excised with a 2 to 3-mm margin. The patient remained free of disease during 77 months of follow-up. Microscopic examination revealed a bulb-like tumor in the dermis, contiguous with the overlyin...

Nevus sebaceous of Jadassohn is a congenital hamartoma that usually affects the scalp and face. Several benign or malignant neoplasias may develop in the lesion and the most common are trichoblastoma, syringocystadenoma papilliferum, and basal cell carcinoma. Trichilemmoma is a benign solid tumor originating from external sheath cells of pilosebaceous follicles. When it is characterized by a ce...

The classification of benign sebaceous neoplasms has been challenged both by the assertion that sebaceous adenomas are really carcinomas and by difficulties in drawing the boundaries between sebaceomas and other lesions. We performed a clinicopathologic study of 30 cases of basaloid neoplasms with sebaceous differentiation, excluding cases of definite sebaceous carcinoma with severe nuclear aty...

BACKGROUND Multinucleated giant cells in the epidermis can either be epithelial or histiocytic. Epithelial multinucleated giant cells are most often associated with herpes virus infections. PURPOSE To review the histologic differential diagnosis of conditions with epithelial and histiocytic multinucleated giant cells-since multinucleated giant cells in the epidermis are not always pathognomon...

BACKGROUND The red squirrel population in Great Britain has declined dramatically in recent decades, principally due to squirrelpox. Concern exists that red squirrels may become extinct nationally and, as there has been limited research in to diseases other than squirrelpox, this study aimed to identify additional causes of mortality. RESULTS Post-mortem examinations on 163 red squirrels foun...

BACKGROUND Adnexal skin tumors share many features in common and differentiate along one line. Their detailed morphological classification is difficult because of the variety of tissue elements and patterns seen. They may be clinically confused with other cutaneous tumors. The aim of this report is to review and classify all adnexal tumors seen in a pathology department over a 16-year period. ...