A Clinicopathological Study of Pilomatricomas in Patients over 50 Years of Age / 대한피부과학회지

ABSTRACT

BACKGROUND: Pilomatricoma is a benign, appendageal tumor differentiating towards the normal hair follicles and is characterized by basaloid, transitional, and shadow cells. It is most frequently seen in children; however, a bimodal onset distribution is observed in the first and sixth decades. OBJECTIVE: The purpose of this study was to analyze the clinical and histopathological features of pilomatricomas in patients over 50 years of age, and to compare these features with those occurring in patients under 20 years of age. METHODS: We retrospectively reviewed the medical records and histopathological findings of 73 patients under 20 years and above 50 years of age. The morphological stages of the tumors were analyzed through histopathological findings. RESULTS: The age of patients in the over 50-year age group ranged from 50 to 82 years, with a mean age of 60 years. The male-to-female ratio was 1.11. The duration of lesions was from 1 month to several years, with half of the patients having the tumors for over 12 months. The predilection sites were the head (51%), followed by the upper extremities (21%), neck (15%), trunk (6%), and lower extremities (6%). In 73% of the patients over 50 years of age, pilomatricoma was less likely the suspected diagnosis compared with that in the under 20-year age group. Epidermal cysts were most likely suspected in patients over 50 years of age. Histopathologically, half of the tumors were located in the subcutis, which was not significantly different when compared with pilomatricomas in the under 20-year age group. The most common evolutional stage of tumors was early regressive (52%), followed by late regressive (27%), fully developed (15%), and early stage (6%). Capsulation (9%), inflammatory cell infiltration (60%), multinucleated giant cells (36%), calcification (33%), and ossification (12%) were observed. With the exception of capsulation, there were no significant differences in these histopathological features in pilomatricomas in patients over 50 years of age compared with those in patients under 20 years of age. CONCLUSION: Pilomatrichomas in patients over 50 years of age show no pain, are located in the head and neck, are present for a long duration, and have various clinical presentations when compared with those in patients under 20 years of age. However, they are not rare tumors in adults. Accordingly, pilomatricomas should be included in the clinical differential diagnosis of a solitary, deep skin tumors presenting in adults, especially when they occur on the head.