Abstract
In the Sapporo Institute for Dermatopathology during the past 5 years, there have been 1,225 cases (1%) diagnosed as poroid cell neoplasms among a total of 122,506 specimens. Therefore, we consider poroid cell neoplasms to be a common disease. We reexamined the clinical data from the 421 cases. There were 199 men and 221 women (1:1.1). The average age was 63.9±15.0 years (12～98 years); 92.9% of patients were more than 40 years old at the time of exision. The tumors were mostly located on the lower extremities (43.4%), particularly on the foot (23.1%). The remainder were found on various regions. The average size was 8.2±5.0 mm (2～43 mm). Pedunculated lesions were the most common clinical form (47.3%). Clinically, this disease resembles seborrheic keratosis, pyogenic granuloma, and verruca vulgaris, so it is difficult to make an accurate clinical diagnosis. There is only 30 cases (7.3%), which made accurate diagnosis at the time of exision, difficult.
