This pathology case review focuses on the diagnosis of a deep angiomyxoma, often referred to as an "aggressive angiomyxoma," in a 35-year-old female presenting with a vulvar lesion. The speaker clarifies that while the lesion is not malignant, the term "aggressive" refers to its tendency toward continuous local growth and recurrence due to its deep, interwoven location within the soft tissues of the pelvis, vulva, and surrounding structures, making complete resection challenging. Histologically, the tumor is characterized by a bland, edematous, myxoid background, intermingled fat, and vessels of highly variable thickness. The key subtle diagnostic feature is the presence of scattered, thin, elongated smooth muscle cells seen branching away from the blood vessel walls. Clinical distinction from common differential diagnoses like stromal polyps relies heavily on the deep angiomyxoma's characteristic presentation as a large, deep-seated mass.
Deep Angiomyxoma (Aggressive Angiomyxoma) Case Review
0:00:12 Case and Diagnosis: The case involves a 35-year-old female presenting with a vulvar lesion, diagnosed as a deep angiomyxoma (also known as "aggressive angiomyxoma").
0:00:25 Tumor Behavior: The term "aggressive" is misleading; these are not classic malignancies. They are difficult to remove because they are deep and interwoven in the soft tissue (pelvis, vulva, uterus), leading to continued local growth and recurrence.
0:00:54 Histological Appearance: The background often resembles edema—pale rather than the deep blue of true myxoid material—with generally low cellularity and intermingled fat.
0:01:07 Vascular Features: A hallmark is the wide range of vessel sizes, from tiny vessels to larger, thick-walled, muscular-looking vessels.
0:01:37 Key Diagnostic Clue: A subtle but helpful feature is the presence of thin, elongated smooth muscle cells scattered among the bland spindle cells in the myxoid background. These cells often branch off the outside of blood vessels and stretch into the surrounding tissue.
0:02:43 Immunohistochemistry (IHC): These tumors are often Estrogen Receptor (ER) and Progesterone Receptor (PR) positive, but this staining is not specific as many stromal tumors in the genital tract share this feature.
0:03:06 Differential Diagnosis (DDx): Includes fibroepithelial stromal polyps and angiomyofibroblastoma, as stromal tumors in this region often have overlapping features.
0:03:23 Critical Distinguishing Factor: Deep angiomyxomas are characterized as big, deep tumors. A small, superficial polyp is highly unlikely to be this diagnosis.
0:03:37 Clinical Significance: The current specimen was part of a large, deep mass (15-20 cm). If any doubt exists regarding the size or depth, the clinician should be prompted to perform imaging studies.