Epithelioid leiomyoma of the larynx.

We describe the pathological features of a case of laryngeal epithelioid leiomyoma (leiomyoblastoma) which, to our knowledge, is the second case to be reported in the world literature. A review of the literature confirmed that leiomyoma as such is a very rare neoplasm in the larynx, and only 33 cases have been previously reported. The neoplasm was located in the left vocal cord and consisted of mainly epithelioid, round or spindle-shaped cells, often with clear cytoplasm, which were arranged predominantly in solid nests and sheets. The tumour cells showed positive immunoreactivity for smooth muscle actin and desmin. The tumour showed low mitotic activity and immunostaining with MIB 1 (Ki-67) accordingly revealed the occasional cell only to be positive, confirming a low proliferative activity in agreement with a benign neoplasm. Epithelioid leiomyomas located in other sites have been shown to act occasionally in a malignant fashion, and the necessity for careful long-term follow-up of the patient is therefore emphasized.