Trichoblastic Carcinoma (Malignant Trichoblastoma) with Lymphatic and Hematogenous Metastases

The document reported a rare case of trichoblastic carcinoma, a malignant transformation of a trichoblastoma, in a 55-year-old man with B-cell chronic lymphocytic leukemia. The primary tumor, present for over 40 years, showed malignant transformation with lymphatic and hematogenous metastases. Despite treatment, the patient died 21 months after diagnosis. This case illustrated the potential for malignant transformation in long-standing trichoblastomas, especially in immunocompromised individuals. The study highlighted that malignant transformation in initially benign lesions could occur, particularly in long-standing tumors and immunocompromised patients. The TC in this case was resistant to radiation and chemotherapy, and the presence of P-glycoprotein might have contributed to this resistance. The pathogenesis of TC was not well understood, but it was suggested that dysregulation of B-cell function and immune impairment might play a role.