Pilomatrical carcinosarcoma in the very elderly: A case report

Pilomatrical carcinosarcomas are very rare tumors. To the best of our knowledge, only nine cases diagnosed with pilomatrical carcinosarcomas have been reported. The present study reported on a case of pilomatrical carcinosarcoma in the posterior part of the left auricle of a 100-year-old male patient. The tumor histologically comprised the following two components: Pilomatrical carcinoma and undifferentiated spindle cell sarcoma. The pilomatrical carcinoma comprised atypical basaloid cells and shadow cells. The basaloid cells had basophilic cytoplasm, clear nucleoli and deeply stained nuclear chromatin. The undifferentiated spindle cell sarcoma comprised atypical spindle cells. Both components contained numerous mitotic cells. The boundary area between the carcinoma and sarcoma smoothly transitioned into each other. The carcinoma cells and a portion of the sarcoma cells were positive for β-catenin in the cytoplasm with or without the nuclei. These results suggested that the two components developed from the same origin.