This video provides a detailed pathological description of Angiomyofibroblastoma (AMF), a benign tumor typically occurring in the vulvar subcutis and showing a female predilection. Microscopically, AMF is characterized by plump, eosinophilic epithelioid or spindle cells arranged in distinctive cords and linear chains stretching through a highly variable stroma (which can be edematous/myxoid or collagen-rich/hyalinized). The presence of dilated, ectatic blood vessels, often surrounded by whirling tumor cells, is a notable feature. Immunohistochemically, AMF is classically positive for Desmin, Estrogen Receptor (ER), and Progesterone Receptor (PR), though caution is advised regarding the non-specificity of the hormonal markers in the female genital tract.
Angiomyofibroblastoma (AMF) in the Vulvar Subcutis
[0:00] Case Introduction: The presentation focuses on a nodule found in the subcutis of the vulva, characterizing a tumor with a female predilection: Angiomyofibroblastoma (AMF).
[0:18] Context: AMF belongs to a collective group referred to as the "benign genital stromal tumors," which, despite being unrelated entities, can share some overlapping microscopic features.
[0:33] Cellular Morphology: The tumor is composed of plump, eosinophilic epithelioid or spindle cells (having eosinophilic cytoplasm and oval to round nuclei).
[0:48] Architectural Pattern: These spindle cells arrange themselves in characteristic cords, strands, and linear chains that stretch throughout the stroma.
[1:00] Stromal Variation: The surrounding stroma is variable, ranging from collagen-rich, hyalinized, or sclerotic to very loose, myxoid, or edematous.
[1:11] Vascular Features: A common feature is the presence of dilated, ectatic blood vessels, around which the tumor cells sometimes swirl and whirl.
[1:47] Key Immunoprofile: On immunohistochemistry, these cells are classically positive for Desmin and the hormonal receptors Estrogen Receptor (ER) and Progesterone Receptor (PR).
[1:56] Key Takeaway/Caution: The presence of ER and PR positivity is not unique to AMF and can be seen in many other neoplasms in the female genital tract.