Differential diagnoses include aggressive angiomyxoma, myxoid neurofibroma (SOX10 positive), soft tissue myxoma (characterized by prominent myxoid matrix), nodular fasciitis (with spindle stellate cells and positive calponin staining) [86,90], and low-grade myxofibrosarcoma (with abundant mucoid stroma, an arborizing capillary network, lipoblasts, and MUC4 positivity) [86,90]. The gene discussed is MUC4; the disease is myxofibrosarcoma.