Malignant schwannoma of the uterine cervix: a study of three cases

Pure sarcomas of the uterine cervix are rare; most of those reported have been leiomyosarcomas or rhabdomyosarcomas. Minimal data exists on malignant nerve sheath tumors in this site; only one typical example and one melanocytic example have been reported. We report three additional examples here in three patients 25, 65, and 73 years of age. The two older patients had vaginal bleeding and underwent hysterectomy as initial treatment. The youngest patient initially underwent only polypectomy. The tumors were 1.3, 4.4, and 5.0 cm in greatest dimension. The tumors were red-grey to white: two were polypoid and the third was ulcerated. The dominant microscopic appearance was that of cellular fascicles of spindle cells with hyperchromatic nuclei and eosinophilic cytoplasm. However, hypocellular areas were striking in each case; the hypocellular areas were fibromatous in two tumors and two had areas with a myxoid stroma (prominent in one). One tumor focally had cellular aggregates with a swirling pattern within a hypocellular background. Epithelioid foci in which tumor cells were rounded with conspicuous eosinophilic cytoplasm were focally prominent in one case. Mitoses were readily identified in each case. All three tumors were positive for S-100 protein and vimentin and negative for cytokeratin. HMB-45, and desmin. One case is recent and one patient had multiple metastases in the abdomen 2 years after hysterectomy. The patient treated initially by polypectomy underwent repeat local excision, followed by cone biopsy with positive margins, and then hysterectomy. She is clinically free of disease 15 months after diagnosis. Although the diagnosis of malignant schwannoma was suggested by the histologic features of the tumors, other diagnoses were entertained and immunohistochemistry was crucial in confirming the diagnosis. These tumors should be distinguished from other malignant spindle cell tumors of the cervix, such as leiomyosarcoma, endocervical "stromal sarcoma," and spindle cell melanoma, so their features, behavior, and optimal therapy can be further delineated.