Extra-Acral Sclerosing Perineurioma

Perineuriomas are uncommon benign peripheral nerve sheath tumors that can arise dermally, subcutaneously or in deep soft tissue. Soft tissue perineuriomas most commonly arise at acral sites however, extra-acral tumors have been reported (trunk, head and neck, retroperitoneum, paratesticular). They are benign tumors that are well circumscribed and characterized by a proliferation of spindle cells that assume a whorled or fascicular growth pattern. The stroma can vary from myxoid to collagenous and sclerotic.