Acral myxoinflammatory fibroblastic sarcoma with hybrid features of hemosiderotic fibrolipomatous tumor occurring 10 years after renal transplantation

Figures

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  Figure 1.. (a) Myxoinflammatory fibroblastic sarcoma (MIFS). This was a multinodular neoplasm centered in the dermal and subcutaneous tissues of the foot. (b–e) There are nodular distributions of numerous atypical, multivacuolated fibroblasts within extensive myxoid stroma (Figure 1(b)–(e)). Also present are small numbers of moderately atypical spindle cells and large cells with prominent enlarged eosinophilic nucleoli (Figure 1(d)). Foci of hemorrhage are present (Figure 1(e)). (f) Hemosiderotic fibrolipomatous tumor (HFLT). Many areas show adipose tissue with intervening, moderately cellular fibrous septa containing mildly atypical spindle cells with hemosiderin pigment deposition. The transition between the areas of HFLT and MIFS ranged from gradual to relatively abrupt (shown here).

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  Figure 2.. (a, b) HFLT and MIFS. The nodular and relatively well-demarcated areas of MIFS (left, Figure 2(a) and (b)) are seen adjacent to the fibrous septa of HFLT (right), which contain spindle cells and prominent hemosiderin pigment deposition. (c) HFLT. Sparsely cellular fibrous septa containing mildly atypical spindle cells intermingle with mature adipose tissue. (d) Bowen’s disease (squamous cell carcinoma in situ). The surrounding skin showed well-demarcated epidermal lesions comprising full thickness distributions of markedly atypical epithelial cells with atypical mitotic figures (Figure 2(d)), but without stromal invasion.