This brief pathology review segment focuses on the diagnostic features of intramuscular myxoma (IM) and contrasts it with cutaneous myxoma (superficial angiomyxoma). The key criteria for IM include a triad of hypocellularity, hypovascularity, and bland nuclei. The video specifically details the characteristic cellular morphology found in both myxoma variants: a cell featuring a bean-shaped nucleus and a small blob of pink cytoplasm, known informally as the "little fat pot belly" cell.
Review of Intramuscular and Cutaneous Myxomas
0:03 Intramuscular Myxoma (IM) Triad: Diagnosis of IM relies on three histological features: hypocellularity, hypovascularity, and bland nuclei.
0:12 Differential Considerations: If the three features are absent, the diagnosis is likely not a myxoma, and other options should be considered.
0:13 Cutaneous Myxoma Distinction: Superficial angiomyxoma (cutaneous myxoma) differs from IM by having prominent vessels.
0:24 IM Histology: Intramuscular myxoma is visually confirmed to be very hypocellular, splaying apart the surrounding skeletal muscle bundles/fibers.
0:33 Key Cell Morphology: A characteristic cell is identified, featuring a bean-shaped nucleus and a small blob of pink cytoplasm. This cell is seen in both intramuscular and superficial angiomyxoma.
0:46 Mnemonic: The characteristic cell morphology is nicknamed the "little fat pot belly" cell.