Case 376 - Discussion

Uploaded: 2009-10-30, Updated: 2009-11-02

Aggressive Angiomyxoma

• Mostly in reproductive female, peak age 30s, M:F=1:6.

• Location: vulvar region.

• Gross: soft, partially circumscribed, polypoid, gelatinous homogenous cut surface.

• Micro:

  • Widely scattered spindle to stellate cells with ill defined cytoplasm, small round or oval hyperchromatic nuclei, and small centrally located nucleoli. Some lesions may have increased cellularity, particularly areas surrounding the vessels.

  • Myxoid background rich in collagen fibers, often with focal hemorrhage.

  • Variably sized, thin- or thick-walled vascular channels.

  • Rare or absent mitotic figures.

  • Prominent mast cells.

• IPX: vimentin+, desmin+, SMA+, MSA+, ER+, PR+, CD34+/- (50%), S100-.

• Prognosis: 30% recurrent rate.

• DDX:

  • Angiomyofibroblastoma: vulva, virgina, small well-circumscribed, plump epithelioid cells in a perivascular distribution, binucleation and multinucleation often seen, many thin wall vessels, no recurrence.

  • Intramuscular myxoma: not in vulva, less cellular, less vascular, more abundant stromal mucin.

  • Cutaneous myxoma (Superficial myxoma): lobular or multinodular, no thin wall vessels, abundant myxoid background, desmin-, ER-, PR-.

  • Myxoid neurofibroma: wavy nuclei, S100+.

Reference: Enzinger and Weiss's Soft Tissue Tumors, 5th Edition. By Drs. Sharon Weiss and John Goldblum. 2007