Definition
This is a newly described tumour of the vulva occurring in prepubertal girls.
Eleven cases have been reported in one paper, all prepubertal, with an average age of eight years.
Presentation is as a painless swelling, usually present for a couple of years. All cases occurred in the vulva, most in the labia majora.
Most lesions were described as ill-defined. They were soft to rubbery with a pink-grey to tan cut surface. Necrosis and haemorrhage were absent.
All cases were non-encapsulated with ill-defined margins. They were hypocellular, composed of bland spindle cells in a wavy collagenous stroma. There were small to medium thick-walled vessels and entrapped lobules of fat and nerve bundles. Skin adnexa may be entrapped. Nuclear atypia was lacking and the mitotic rate less than 1/10 HPF. Small numbers of neutrophils and lymphocytes were present.
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8/9 (multifocal to strong staining) |
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0/9 |
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0/9 |
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0/9 |
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0/9 |
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0/9 |
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Aggressive angiomyxoma occurs in adult women. The stroma is diffusely myxoid with only delicate collagen fibrils. There is perivascular small muscle proliferation. There is positivity for desmin.
Angiomyofibroblastoma occurs in peri- and post-menopausal women. It is well circumscribed with a thin fibrous capsule. Cellularity is varied. The tumour cells aggregate around blood vessels and are positive for desmin.
Cellular angiofibroma occurs in adult women. It is better demarcated and is more cellular than prepubertal vulval fibroma. The vessels within the lesion are hyalinised. Immunohistochemistry is variable.
Neurofibroma has wavy nuclei and is positive for S-100.
Superficial angiomyxoma is hypocellular and has a myxoid stroma. It is lobulated with prominent neutrophils. There is positivity for SMA as well as for CD34.
Fibroepithelial polyp occurs in adult women. It is usually vaginal but may occur in the cervix. There may be nuclear pleomorphic and frequent mitoses. It is positive for desmin.
Botryoid embryonal rhabdomyosarcoma occurs in infants. It grows in grape-like polyps. It is a cellular lesion with hyperchromasia and atypia. A hypercellular subepithelial cambium layer is present. There is positivity for desmin and skeletal muscle markers (myogen, MyoD1).
Complete resection is required to avoid local recurrence.
This page last revised 4.1.2005.
©SMUHT/PW Bishop