Superficial cervico-vaginal myofibroblastoma: a report of five cases

Abstract

To describe the pathological and immunohistochemical features of five cases of superficial cervico-vaginal myofibroblastoma (SCVM), a recently described mesenchymal tumour affecting middle-aged and elderly females. The histological features of five cases of SCVM arising in four patients were reviewed including one case which recurred locally 9 years after initial excision biopsy. All cases were immunostained using the streptavidin-biotin technique using antisera to vimentin, smooth muscle actin, desmin, S100 protein, cytokeratin, h-caldesmon, calponin, CD99, CD117 (c-kit), bcl-2, oestrogen receptor and progesterone receptor. The patients were aged from 40 to 71 years (mean 55.2 years). The tumours were situated within the vagina (four cases) and cervix (one case) and ranged from 16 to 45 mm in greatest dimension. One patient had two separate vaginal SCVM. The tumours were characterised by uniform spindle and stellate-shaped cells separated by a collagenous or myxoid stroma. No mitotic activity was identified. Characteristically the tumours were well circumscribed and separated from the surface epithelium by a rim of normal stroma. The initial and recurrent tumours in one patient were similar except for increased stromal collagen in the recurrence. All tumours were immunoreactive for vimentin, desmin, CD34, CD99, bcl-2, calponin and hormone receptors while two tumours showed focal smooth muscle actin expression. There was no expression of S100 protein, h-caldesmon, CD117 or cytokeratin. SCVM appears to be a relatively distinct lesion although there is some histological and immunophenotypical overlap with other mesenchymal tumours, particularly fibroepithelial polyp, leiomyoma and solitary fibrous tumour. As local recurrence developed 9 years after intial treatment in one patient, long-term clinical follow-up would seem appropriate.