Concurrent pilomatrix carcinoma and giant pilomatrixoma

Area of Science:

• Dermatology
• Surgical Pathology
• Oncology

Background:

• Pilomatrixoma is a benign skin tumor originating from hair follicle matrix cells.
• Pilomatrix carcinoma is a rare malignant adnexal neoplasm with limited reported cases.
• Distinguishing between pilomatrixoma and pilomatrix carcinoma is crucial for appropriate management.

Observation:

• A 52-year-old male presented with two distinct lesions on his left lower limb: a fungating thigh mass and a smaller knee mass.
• Both lesions were initially similar but the thigh mass rapidly enlarged and fungated over 6 months.
• Pathological examination revealed pilomatrix carcinoma of the thigh and pilomatrixoma of the knee.

Findings:

• The pilomatrix carcinoma was successfully excised with no recurrence or metastasis after 3 years.
• The clinical progression suggests a potential malignant transformation of pilomatrixoma into pilomatrix carcinoma.
• Literature review indicates lower limb pilomatrix carcinoma may exhibit increased metastatic potential.

Implications:

• This case highlights the importance of vigilant monitoring for changes in pilomatrixoma.
• Early diagnosis and wide surgical excision are critical for managing pilomatrix carcinoma.
• Further research is needed to understand the oncogenesis and metastatic behavior of lower limb pilomatrix carcinoma.