Three Cases of Hidroacanthoma Simplex / 대한피부과학회지

Hidroacanthoma simplex (HS) is a rare benign intraepidermal tumor thought to originate from the intraepidermal eccrine duct. Many authors regard it as an intraepidermal form of eccrine poroma but there is still a discussion as to the histogenesis of HS. Clinically, it is more common in older adults and affects both sexes equally. It is found more often on the lower extremities and trunk. The clinical appearance is not characteristic, but the lesions are usually flat or slightly elevated verrucous brown plaques. Histopathologically, the tumor shows characteristic intraepidermal nests and is one of a number of cutaneous lesions showing Borst-Jadasshon phenomenon, that is, tendency to form nests within the epidermis. The tumor cells composing nests show a uniform cuboidal appearance and a round, deeply basophilic nucleus typically. The cytoplasm of tumor cell gives a positive PAS reaction that is diastase-labile. We report herein three cases of HS with the results of immunohistochemical studies.

Eccrine Squamous Syringometaplasia

An eccrine squamous syringometaplasia (ESS) is defined as a mature squamous metaplasia of the eccrine ducts. The clinical and pathological features of an ESS are presented. Syringometaplasia is a rare lesion, mostly occuring in the extremities, and as far as we know, no report on the ESS has been published in Korean literature. We experienced a case of an ESS occured in a 15 year-old male, who had a tender erythematous plaque in the right knee. The histologic examination revealed some scattered nests of metaplastic squamous epithelium in the deep dermis, associated with acute nonspecific panniculitis. The importance of the ESS is that it histologically simulates the well differentiated squamous cell carcinoma. The histopathologic findings were discussed and a brief review of the literature was made.

A Case of Porokeratotic Eccrine Ostial and Dermal Duct Nevus

We report a case of porokeratotic eccrine ostial and dermal duct nevus in a 28-year old man. The skin lesions, present since birth, were multiple keratotic papules and punctate pits on the palms, soles and heels bilaterally. Histopathologically, the lesion was characterized by dilatation and hyperplasia of the eccrine sweat ducts with parakeratotic plugs related to sweat gland pores. This entity should be considered the differential diagnosis of other types of porokeratosis and comedo-like keratosis on palms and soles.