Abstract

The clear hidradenoma, generally regarded as an eccrine sweat gland origin, is an uncommon tumor and occurs as a slowly growing, usually solitary nodule. The histologic patterns varies from one tumor to another and in different parts of the same tumor. The histologically variable patterns, therefore, are expressed in various names, including nodular hidradenoma, eccrine acrospiroma, squamous poroadenoma, and solid cystic hidradenoma. During the past 16 years the authors experienced 5 cases of clear cell hidradenoma which were diagnosed by the histopathological examination of the tumor mass removed by surgical excision. Clinical and pathological features were reviewed and the following results were obtained. 1) The mean age was 34 years with a range from 27 to 45 years. Three were male and two female. 2) The chiefr complaint was intradermal or subcutaneous nodules for a period of several years to 15 years. All cases occured as a solitary nodule without a distinct predilection for certain sites. A nodule which situated in the dermis and was accompanied by superficial ulceration was elevated above the skin surface in one case. 3) Grossly, the tumors were relatively well circumscribed and composed of multiloblated masses in 4 cases. They ranged in size between 1.5 and 3.5 cm. 4) Microscopically, all cases disclosed lobulated solid masses separated by varying amounts of collagenous connective tissue. There were often cystic spaces, which were lined by a single row of cuboidal cells in four cases and were bordered by tumor cells in remaining one case. These cysts contained a faintly eosinophilic homogeneous material. On solid portions of the tumor there were two types of cells (clear cell and polygonal cell), the proportions of which varied from tumor to tumor in three cases. The remaining two cases were predominantly composed of clear cells. Tubular lumina which were lined by cuboidal or columnar ductal cells were found in two cases. Areas of squamous differentiation and squamous eddies were seen in one case. Intracytolasmic PAS-positive materials were shown in all cases, but diastase-resistant PAS materials in two cases.

• Keywords: Clear cell;polygonal cell;cystic portion;solid portion;tubular lumina;