C. Allison 1, S. Huilgol1,2
Benign cellular ﬁbrous histiocytoma (CFH) is a variant of ﬁbrous histiocytoma (FH), ﬁrst described by Calonje et al in 1994 (1, 2). Classically, histology of CFH demonstrates high cellularity, limited polymorphism, a fascicular growth pattern with a partly storiform pattern and limited, lace- like pattern of fat inﬁltration (3–6). CFH comprise 5% of dermal ﬁbrous histiocytomas (3, 5). Clinically, CFH can be frequently confused with dermatoﬁbrosarcoma protuber- ans (DFSP). The differentiation of these tumours therefore requires histological examination plus immunohistochemi- cal staining. Despite being described as benign, 26% of CFHs recur, with rare cases reported of pulmonary and lymph node metastases (7–10). We present an educational case of CFH in a healthy 28-year-old man initially mas- querading as DFSP clinically and unable to rule out histo- logically; highlighting the importance of recognition of this rare tumour. On subsequent wide local excision, the histo- logical analysis of the tumour showed increased cellular- ity, spindle-shaped calls with a fascicular and storiform growth pattern and CD34 positivity on immunochemistry. We present the key clinicopathological features to distin- guish DFSP and CFH and a literature review on these rare CFH tumours.
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