Imaging findings of head and neck dermatofibrosarcoma protuberans

Abstract

Background and purpose: Dermatofibrosarcoma protuberans is a rare, locally aggressive sarcoma of the skin in children and adults, usually involving the trunk and extremities and less commonly the head and neck. Despite clinical reports in the literature on the management of dermatofibrosarcoma protuberans, there are limited articles describing its imaging features.

Materials and methods: We retrospectively reviewed the demographics and imaging findings in all 24 patients with pathologically proven dermatofibrosarcoma protuberans of the head and neck seen at a tertiary cancer center between 2001 and 2010.

Results: Twenty-two of the 24 lesions were nodular and well circumscribed; 19 of the 24 were located on the scalp. On imaging, all 24 lesions involved subcutaneous tissues. The lesions ranged in size from 0.6-9.5 cm (mean, 3.7 cm; standard deviation, 2.3 cm). Twelve lesions involved the soft tissues either at or extending directly to the midline. Thirteen lesions were associated with bulging of the skin surface. Fourteen lesions were imaged with CT and 14 with MR imaging. Whereas variable enhancement patterns were noted on CT and MR imaging, dermatofibrosarcoma protuberans was usually T2-hyperintense and demonstrated marked enhancement. None of the lesions was associated with bone invasion, perineural spread, or nodal/distant metastasis.

Conclusions: Knowledge of the imaging characteristics of dermatofibrosarcoma protuberans may alert neuroradiologists to include dermatofibrosarcoma protuberans in the differential diagnosis of lesions about the head and neck with similar imaging characteristics.

Fig 1.

A 31-year-old woman (patient 10) with DFSP of the right parietal scalp. Contrast-enhanced axial CT in soft tissue (A) and bone window (B) shows a 6.1 × 4.8-cm heterogeneously enhancing mass (A, arrow) that bulges the skin surface outward and thins underlying calvaria (B, arrow).

Fig 2.

A 31-year-old man (patient 1) with DFSP of the parietal midline scalp. MR imaging shows a 3.5 × 1.8-cm T1-isointense, T2-hyperintense, coalescing nodular mass with marked homogeneous enhancement in the parietal midline scalp (arrows). A, Axial noncontrast T1. B, Fast spin-echo T2 with fat saturation. C, T1 postcontrast axial with fat saturation. D, T1 postcontrast coronal with fat saturation.

Fig 3.

Photographs of 2 patients with DFSP. A, Patient 16, a 25-year-old man with a large DFSP of the scalp extending from the midline near the vertex down to the left lower parietal region with subcutaneous infiltration. B, Patient 10, a 31-year-old woman with a large DFSP of the right paramedian posterior parietal scalp.

Fig 4.

Pathologic specimen of DFSP. A, Hematoxylin and eosin stain. Elongated spindle cells with a storiform (whorled) pattern arranged around foci of collagen or vascular spaces, radiating outward (arrows). B, CD34 stain. The specimen is positive for CD34 staining. Fat entrapment is noted with a honeycomb pattern (arrow).