BACKGROUND Seborrheic keratosislike melanoma could be one of the most problematic melanoma simulators, and it may be incorrectly treated by electrocautery or cryotherapy. Dermoscopic examination of pigmented tumors improves the diagnostic accuracy in these challenging lesions. In these tumors, numerous comedolike openings are present. OBSERVATIONS A 34-year-old man was seen for a conspicuous ...

An 83-year-old woman presented with a 10-year history of a slowly growing, painful mass in the left auricle and bloody otorrhea. We observed a sharply delineated, domelike blackish-brown verrucous nodular elevation with a greasy scaled surface extending from the left cavum concha into the external auditory meatus (Fig. 1). Gentle manipulation of the growth resulted in mild bleeding and caused s...

Leser-Trélat sign is characterized by the abrupt appearance of multiple seborrheic keratoses in association with underlying malignant disease. A case of Leser-Trélat sign in a 66-year-old healthy woman is presented. Evaluation and follow-up for the development of malignancy over a 2-year period failed to reveal any evidence of malignancy. To date, almost all cases of Leser-Trélat sign have been...

To investigate the function of trichohyalin during terminal differentiation of the skin, immunohistochemical studies were performed on trichohyalin and its related proteins, filaggrin and involucrin, the components of the cornified cell envelope. In skin disorders unrelated to tumours, weak trichohyalin expression was found in a few granular cells or in the horny layer of psoriasis, ichthyosis,...

Trichoadenoma is a rare skin tumor first described by Nikolowski. There are variable clinical features and tumors have been diagnosed as cysts, basal cell epithelioma and seborrheic keratosis. The microscopic feature mainly consists of numerous cysts surrounded by eosinophilic cells. Trichoadenoma is benign and treatment is by simple excision. We report a case of trichoadenoma on the nose...

Seborrheic keratosis is a common benign epidermal tumor histologically composed of basaloid and squamous cells. It mainly occurs on the face, scalp, and trunk, and presents clinically as a well-circumscribed, brownish to black papule, nodule, or plaque. Trichoblastoma is a relatively rare benign, slow-growing tumor showing differentiation toward the primitive hair follicle. It clinically manife...

AIMS The viral etiology of certain types of seborrheic keratosis (SK) has been a controversial subject in literature, with different molecular results. On the contrary, to the molecular approach, some have suggested that certain types of SK are indeed warts, due to their morphologic features. We decided to investigate the presence of coarse keratohyalin granules in cases of irritated SK. MATE...