Histological and immunohistochemical study of 2 cases of deep soft tissue leiomyoma

Abstract

Introduction Deep leiomyomas are benign neoplasms, which are rarely encountered, with location other than the gynecological tract. These neoplasms exhibit smooth muscle differentiation and can be located in the deep soft tissue, retroperitoneum, mesentery, omentum, within the abdominal cavity and have an increased prevalence in women. Purpose The aim of our study is to provide useful information on some aspects of the immunohistochemical profile underlying this specific type of tumor. Material and methods Our study involved 2 cases of postmenopausal women with clinical diagnosis of retroperitoneal tumor. We examined paraffin-embedded tissue sections cut at 3µm and stained with hematoxylin-eosin. A large panel of immunohistochemical markers were used including the following: Anti-PCK, EMA, S100, Vim, ER, PR, Melanosome, HMB45, Ki67, Desmin, SMA, CD34, Caldesmon. Results Histologically, they are classic leiomyomas, similar to those encountered in the gynecological tract. LM are composed of spindle cells with smooth muscle morphology: oval nuclei, frequently with blunt ends (cigar-shaped), perinuclear clear vacuoles and fibrillary eosinophilic cytoplasm. Conclusions Deep leiomyomas occur preferentially in women during the perimenopausal period, and most commonly have a retroperitoneal location. These tumors are commonly positive for estrogen and progesterone.