2022 Volume 21 Issue 2 Pages 114-118
A 74-year-old man presented with a painful nodule on the pad of the left first toe that had been present for 6 years. On examination, a reddish, elastic hard, mildly tender, mobile nodule (6×5 mm) was observed. Ultrasonography showed a hypoechoic mass without blood flow signal. These findings led to the suspicion of glomus tumor and the nodule was resected. Histopathological examination showed a well-defined nodular lesion that was composed of a sheet-like proliferation of round, eosinophilic cells with marked hyperchromatibility and variability in size and shape of nuclei. There was no increase in mitotic activities or atypical mitotic figures. In some cells, typical features of glomus tumor without nuclear atypia were observed. Immunohistochemistry revealed diffuse αSMA positivity and Ki-67 (mib-1)-positive cells were less than 1%. The tumor was diagnosed as symplastic glomus tumor, a variant of glomus tumor. Although it shows marked nuclear atypia and cellular variability, symplastic glomus tumor is a benign tumor that is clinically sharply marginated,superficially located, and small in size and histologically does not show increased mitotic activities or atypical mitotic figures. It is important to recognize this rare tumor and differentiate it properly from malignant tumor. Skin Research, 21 : 114-118, 2022
