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Case Reports

Abstract

Superficial CD34-positive fibroblastic tumor (SCPFT) is a rare, recently recognized low-grade mesenchymal neoplasm. Its distinctive morphology and immunophenotype are crucial for accurate diagnosis and distinction from histologic mimics.

We report the clinicopathologic findings of a 19-year-old female presenting with a painless, slowly enlarging nodule on the mid-abdomen. The excised specimen revealed a firm, tan-white, well-circumscribed mass confined to the dermis and superficial subcutis. Histologic sections showed a moderately cellular proliferation of spindle to epithelioid fibroblastic cells arranged in fascicles and sheets within a collagenous stroma. The tumor cells exhibited vesicular nuclei with prominent nucleoli, mild nuclear pleomorphism, and abundant eosinophilic cytoplasm. No increased mitotic figures activity or necrosis was identified. Immunohistochemical staining showed diffuse strong positive staining for CD34 and negative staining for S100, factor 13A, desmin, and SMA.

SCPFT in patients under 20 years is exceptionally rare, with only isolated reports in patients aged 8, 11, and 16 years. Reported lesions were uniformly CD34-positive with positive staining for Vimentin in two cases. Two cases demonstrated low proliferation activity index (1-2 %); PRDM10 rearrangement was variably present (negative in an 8-year-old chest wall tumor; positive in a 16-year-old forearm tumor; not reported in an 11-year-old female in the axilla). Interestingly, one rearranged SCPFT showed a diffuse AE1/AE3 staining. All pediatric cases with follow-up showed no recurrence or metastasis after complete excision.

Our case expands the spectrum of SCPFT to include young adults and integrates a review of pediatric/adolescent cases, emphasizing the need for awareness, complete excision, and long-term follow-up.