small round cell tumorが疑われた乳児耳下部石灰化上皮腫例

抄録

Small round cell tumors are histopathologically characterized by proliferation of small, round, relatively undifferentiated cells. Small round cell tumors are generally malignant tumors, such as Ewing’s sarcoma, peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin’s lymphoma, and Wilms’ tumor. Histopathological examination is usually to make a definitive diagnosis of this type of tumor.

In this paper, we report the case of a one-year-old male infant with a benign tumor (pilomatrixoma) who was brought to our hospital with swelling of the right parotid region. Fine-needle aspiration cytology led to the suspicion of a small round cell tumor; however, biopsy of the tumor revealed findings suggestive of pilomatrixoma. Therefore, under the tentative diagnosis of a benign tumor, operation was performed. This case presented that diagnosis of small round cell tumor is difficult, and to avoid unnecessary surgery or examinations, we should not forget the possibility of benign tumors such as pilomatrixoma.