Liver Metastasis of Malignant Pilomatrixoma: Devastating Outcome from A Possibly Under-Treated Case

Malignant of pilomatrixoma, known as pilomatrix carcinoma, is a rare cutaneous adnexal tumor that derives from hair matrix cells.The tumor usually occurs in male, with the predominant age range between 40 to 60 years old, located in the head and neck area. The tumor consisted of atypical basaloid cells aggregation, ghost cells, and keratinous material. We report a case of 54 years old male patient referred to Cipto Mangunkusumo Hospital Jakarta with a mass in his right upper quadrant abdomen and a lump in the axilla. The magnitude resonance imaging (MRI) and positron emission tomography (PET)-scan revealed metastatic lesions in several lymph nodes and internal organs. The patient underwent liver biopsy which showed that tumor was composed of atypical basaloid cells, amyloid-like material, keratin mass, and was diagnosed as pilomatrix carcinoma. This case is being reported due to its rarity, potential pitfalls due to histologic similarity with several other entities, and to show the importance of histopathology examination in patient’s treatment to prevent a devastating outcome.