Perivascular epithelioid cell tumors of the laryngopharynx: three case reports and literature review.

Perivascular epithelioid cell tumor (PEComa) of the laryngopharynx is extremely rare, and no such descriptions have been reported in the literature. This study describes the clinical, histological, and immunohistochemical features of three cases of laryngopharynx PEComa. The patients (two males and one female) were 38, 42, and 47 years old, respectively. Their tumors were well-demarcated, gray white on the cut surface with focal hemorrhage, and ranged from 3.0 to 5.0cm in diameter. Microscopically, the tumors were characterized by an epithelioid arrangement of tumor cells, which had abundant clear to pale eosinophilic granular cytoplasm, vesicular nuclei, and prominent nucleoli. The stroma was rich in capillaries, sinusoidal vasculature, and thick-walled blood vessels. Mitotic figures were rare. The tumors showed no cellular atypia, with two of them having moderate atypical nuclei focally. Immunohistochemically, the tumor cells were diffusely or focally positive for vimentin (3/3), HMB-45 (3/3), melan-A(3/3), alpha-smooth muscle actin (3/3), and S-100(1/3). They were uniformly negative for CK, Syn, CgA, CD34, CD10, and CD117. Two patients are well, with no evidence of disease at 13 and 30 months after surgery, one patient had recurrence at 15 months after operation. Laryngopharynx PEComas should be regarded as tumors with a malignant potential.