Fibrosarcomatous Dermatofibrosarcoma Protuberans of the Head

Abstract

This article highlights the case of a 37-year-old male who presented with a recurrent, exponentially enlarging head mass, emphasizing the diagnostic and therapeutic challenges associated with a very rare type of tumor, fibrosarcomatous dermatofibrosarcoma protuberans (DFSP) of the head. Our patient presented with a rapidly growing head mass, initially diagnosed as a spindle cell tumor, and was managed with surgical excision and skin flap grafting. Follow-up revealed relapse and interval development of hemiparesis and hemisensory loss. MRI revealed tumor recurrence, with compression of the right parietal lobe and superior sagittal sinus. Histopathology revealed stroma with fascicles of spindle cells homogenous to fibrillar cytoplasm, with oval vesicular nuclei. Immunohistochemical staining showed positivity for CD34 and SMA. Oral chemotherapy with imatinib 800 mg/day was started. Follow-up imaging showed a marked reduction in the size of the tumor and resolution of the compression of the underlying brain parenchyma with cystic degeneration and decreased contrast enhancement. Future plans include possible surgical tumor debulking and/or radiation therapy. Although extremely rare, awareness of this tumor, with a multi-disciplinary approach to the management of the case, is vital to maximize treatment outcomes.

Keywords: cd34+; dermatofibrosarcoma protuberans; fibrosarcomatous transformation; imatinib; sma.

Figure 1. Representative images of the patient’s MRI show a large heterogeneously enhancing tumor, measuring 14.5x14.2x11.9 cm (APxTxCC), shown in coronal T1-weighted (A), T2-weighted (B), sagittal (C), and coronal (D) images. MRV images show a highly vascular tumor that receives supply from scalp arteries and drains via cortical and emissary veins.

Figure 2. Representative slides of the tumor show spindle-shaped cells with homogeneous fibrillar cytoplasm and oval vesicular nuclei in HE stain (A). Cells were diffusely positive for CD34 (B), focally positive for SMA (C), negative for desmin (D), cytokeratin (E), S100 (F), STAT6 (G), TLE1 (H), MUC4 (I), and EMA (J).

Figure 3. Actual photographic documentation of the reduction of the tumoral size at baseline (A,C) in comparison with four months post-imatinib (B,D).

Figure 4. Representative sagittal T1-weighted MRI images of the tumor prior to treatment (A) and four months post-imatinib (B), showing an overall reduction in tumoral volume and size, now measuring 12.4x12.0x14.3 cm (APxTxCC), with decreased enhancement cystic degeneration, attributable to tumor necrosis.