Table 1.
Clinical and histopathological features of vulvar angiomyxomas.
| Superficial angiomyxoma | Aggressive angiomyxoma | |
|---|---|---|
| Age | Mean: 23 years. Range: 15–60 years |
Most common: women of reproductive age. Range: 16–70 years |
| Incidence | ∼50–60 cases reported | ∼350–400 cases reported |
| Clinical presentation | Soft lobulated mass | Pedunculated mass, can be lobulated, soft to rubbery |
| Size | Varies, usually small (ranges from 0.9 to 4 cm) | Varies (ranges from 3 to 60 cm), usually larger (most > 10 cm) |
| Imaging | Preserved fat plane between the mass and levator muscles. MRI: Iso- to hypo-intense signal to muscle on T1WI, homogenous hyper-intense signal on T2WI with heterogeneous enhancement on postcontrast T1WI. |
Tends to involve levator muscles and/or deep pelvic structures. MRI: Iso- to hypo-intense signal to muscle on T1WI, homogenous hyper-intense signal on T2WI with swirl/laminated appearance, and progressive avid enhancement on postcontrast T1WI. |
| Gross pathology | Variably circumscribed, unencapsulated, superficial dermal nodule with multinodular gelatinous cut surface with thin fibrous septa, may contain cysts with keratin debris | Variably circumscribed, unencapsulated, deep-seated lobulated or polypoid mass, myxoid, gelatinous, or rubbery cut surface |
| Cell origin | Histogenesis is uncertain, may arise from fibroblast-like mesenchymal cells | Histogenesis is uncertain, may arise from specialized mesenchymal cells and/or multipotent perivascular progenitor cells |
| Histology | Hypocellular dermal nodule of spindled to stellate cells in an abundant myxoid background (neutrophils present in a subset of cases), numerous arborizing small thin-walled blood vessels. Entrapped benign epithelial elements may be present. | Hypocellular lesion of small spindled to stellate cells with an infiltrative growth pattern (entraps fat and nerves), abundant myxomatous stroma with collagen fibers, numerous variably-sized blood vessels with occasional perivascular smooth muscle proliferation, stromal mast cells and extravasated red blood cells common |
| Nuclear atypia | Absent | Absent |
| Mitotic index | Low | Low |
| Immunohistochemistry | Vimentin + S100 –Mucin (via Alcian blue PAS) + Desmin – or focal ER/PR – SMA – or focal CD34 + HMGA2 – |
Vimentin + S100 –Mucin (via Alcian blue PAS) + Desmin + ER/PR + Variable SMA CD34 – HMGA2 overexpressed |
| Genetic testing | If associated with Carney complex, may have autosomal dominant inactivating mutations in PRKAR1A (17q22-24) | Various rearrangements involving HMGA2 (12q13-15) in approximately 1/3 of cases |
| Treatment | Simple excision | Wide local excision +/- Adjuvant hormonal therapy |
| Recurrence rate | 30–40% (∼with inadequate resection) | 50–70% (∼with inadequate resection) |
| Metastasis | No | Extremely rare |
MRI: Magnetic resonance imaging; T1WI: T1 weighted image; T2WI: T2 weighted image; PAS: Periodic Acid Schiff; ER: Estrogen receptor; PR: Progesterone receptor; SMA: Smooth muscle actin; HMGA2: High mobility group A2 protein; PRKAR1A: Protein kinase CAMP-dependent type I regulatory subunit alpha.