A 28-year-old Mediterranean female with unremarkable medical history, attended the out-patients department, with a 45-day history of a painless rapidly growing lesion in the right cheek (infra-auricular area). Clinical examination revealed a protruding painless red-bluish mass, which was associated with the skin over the parotid area. The lesion (sized 10 × 5 × 4 cm) was firm, fixed to deeper tissues with propensity to bleed. No facial nerve involvement was noted (Figure ).
Clinical image showing an infra-auricular lesion (10 × 5 × 4 cm in size).
Ultrasonographic examination revealed a well vascularized mass infiltrating the subcutaneous fat and the parotid. Computed tomographic and magnetic resonance imaging evaluation revealed a parotid mass fixed to sternocleidomastoid muscle and adherent to overlying skin; multiple small lymph nodes involvement along the jugular vein were also noted (Figures and ). No distant metastasis was reported. Fine needle aspiration cytology reported a mesenchymal lesion; incisional (true-cut) biopsy, under local anesthesia showed a possible grade II sarcoma (storiform malignant fibrous histiocytoma).
Computed tomography image showing a parotid mass adherent to overlying skin.
Magnetic resonance image showing a soft tissue mass associated with the parotid gland.
The decision was made, in a multi-disciplinary meeting, to treat the tumour with wide local resection. This involved a superficial parotidectomy and selective neck dissection (levels II-V). The defect was reconstructed with a large neck pedicle advancement flap (Figure ).
Postoperative image following local excision and reconstruction.
Histopathological examination, of the completely excised tumour, revealed a nodular neoplastic lesion composed of large spindle-shaped cells with prominent nuclei, showing a high mitotic index and areas of necrosis, infiltrating into the subcutaneous fat and muscles (Figure ). Further immunohistochemical analysis revealed tumour cells which were positive for CD34, and c-kit antigen. A few cells were positive for SMA and CD68. Staining for Ki67/MIB 1 showed 50% positive cells and increased mitotic rate (>20/10 HPFs). It was concluded that this constellation of staining represented a "dermatofibrosarcoma protuberans with fibrosarcomatous transformation" (Figure ).
Histopathology image showing dermatofibrosarcoma protuberans. (a) H&E ×10 spindle-shaped tumor cells in a "cartwheel" pattern. (b) H&E ×40 showing increase number of mitosis.
Histopathology image showing immunopositivity to CD34. (a) ×25 showing immunopositivity to CD34. (b) ×40 showing immunopositivity to CD34.
Following the diagnosis, the multi-disciplinary team decided that an adjuvant therapy would be required. The patient, subsequently, received 60 Gy of radiation therapy and subsequent recovery was unremarkable. At 35-month post-treatment follow-up, the patient continues to be symptom free with no signs of tumour recurrence.