Aggressive angiomyxoma of the inguinal region

Aggressive angiomyxoma is a distinctive and very rare soft tissue tumor occurring almost exclusively in women. Only seven cases occurring in men have been previously reported. We herein report a case of a 74-year-old man who was admitted to our hospital presenting with a huge right inguinal mass that had grown over a 14-year period, in order to undergo surgical treatment for gastric cancer. The inguinal tumor was well-defined and demonstrated a glistening appearance on the cut surface. Histologically, the tumor was composed of bland-looking spindle and stellate cells with delicate cytoplasmic processes, which sparsely populated the fibromyxoid matrix. A prominent vascular component was also present. Immunohistochemically, the stromal cells stained consistently for vimentin and variably for muscle-specific actin, but not for alpha-smooth muscle actin, desmin, and S-100 protein. The gastric cancer was microscopically diagnosed to be papillary adenocarcinoma with serosal invasion and showing immunoreactivity for p53 protein, but not for aggressive angiomyxoma.