To the Editor:
In their interesting case report (1), de Gálvez-Aranda and coworkers are presenting a patient with a pilomatrix carcinoma showing metastatic spread. Moreover, the authors itemize 8 cases from the literature that also led to metastases of a pilomatrix carcinoma. I would like to refer to a further, very interesting case of a pilomatrix carcinoma with multiple metastases from the German-speaking literature, published by Mack and coworkers in 1994 (2).
In this study, the authors report on a male patient in whom a pilomatrix carcinoma was excised from the left big toe at age 40. It was but 5 years later that metastases of the left inguinal lymph nodes appeared. An excision was followed by radiation therapy of the left inguinal region. Eighteen years later it came to a general metastatic spread, affecting thoracal and abdominal lymph nodes, the lung, liver, vertebral bone, and left ureter. This case report clearly underlines the potential of delayed metastatic spread in pilomatrix carcinomas discussed by de Gálvez-Aranda and coworkers. Furthermore, it contains information concerning the question of these authors if radiation therapy may be of value in the treatment of pilomatrix carcinoma: The patient in the case report of Mack and coworkers was free of further metastases for 18 years after radiation of his left inguinal region where the first metastases occurred.
Tilman Schulz, M.D.
1. De Gálvez-Aranda MV, Herrera-Ceballos E, Sánchez-Sánchez P, et al. Pilomatrix carcinoma with lymph node and pulmonary metastasis. Am J Dermatopathol 2002; 24:139–43.
2. Mack U, Back W, Reiter S. Pilomatrixkarzinom mit polytoper Metastasierung nach 23 Jahren. Akt Dermatol 1994; 20:351–5.