Pilomatrix Carcinoma of the scalp. A case report and review of the literature

Summary Introduction Pilomatrix Carcinoma (PC) is a rare and malignant dermo-hypodermic tumor. Only 11 cases were reported in patients younger than 18 years old and only 13 cases were reported on the scalp. Case report We report the case of a 15-year-old woman who underwent cyst excision on the vertex. Anatomopathology shed light trichilemmal cyst. Five months later, she presented a first local recurrence. The tumor was removed with wide margin. Anatomopathology shed light PC. No adjuvant therapy was performed. The patient presented a second recurrence 3 months later with a parietal bone and superior sagittal sinus invasion and a lung metastasis. She underwent a craniotomy and radiochemotherapy. A third local recurrence was detected 4 months later. Three more lines of chemotherapy were performed without success. Discussion PC is a locally aggressive tumour, with a high rate of local recurrences and metastases. PC arises de novo or through malignant transformation of a pilomatrixoma. PC were observed frequently in the white male over 50 years old. The histological diagnosis is difficult to prove. Treatment consists of a wide surgical excision. Peritumoral margins are not codified. Because of most cases are on the face and neck, Mohs Micrographic Surgery seems to be a good modality to limit margins. Radiation therapy is an adjuvant treatment. Chemotherapy can be used in metastasis case. Conclusion PC is a rare malignant tumor with high rate of disease relapse. Histological diagnosis is difficult and treatment is not standardized. Surgical procedure with wide margins is recommended to avoid the large recurrence when the staging shows no metastasis.