A 60-year-old woman presented with the complaints of recurrent swelling on her upper back \[[Figure 1](#F1){ref-type="fig"}\]. It was present since her childhood and was small, painless, and did not change in size. Two years back, due to trauma, the swelling started increasing in size, with the complaint of pain and also bloody discharge. The patient then got it excised one-and-a-half years back. On histopathologic examination, the diagnosis of dermatofibrosarcoma protuberans (DFSP) was made. Six months later the swelling recurred and gradually increased in size. This time a wide local excision was performed. Grossly, the specimen received was a skin covered soft tissue piece measuring 6.5 × 6.0 × 1.0 cm. On cutting, it revealed a well-circumscribed grayish white mass in the subepidermal tissue measuring 3.5 × 2.0 × 1.0 cm \[[Figure 2](#F2){ref-type="fig"}\]. Microscopically, a section covered by stratified squamous epithelium with uninvolved zone of dermis was seen. The underlying tissue showed a well-demarcated tumor composed of uniform population of slender fibroblasts arranged in a storiform pattern. The cells showed mild nuclear pleomorphism and rare mitosis. The tumor was seen infiltrating subcutaneous fat \[[Figure 3](#F3){ref-type="fig"}\]. Furthermore, immunohistochemical analysis revealed tumor cells positive for CD34. And hence, the diagnosis of DFSP was made. Presently, the patient is under regular followup and is stable.

![Clinical photograph of dermatofibrosarcoma protuberans presented as back swelling](IDOJ-4-68-g001){#F1}

![Gross specimen of dermatofibrosarcoma protuberans forming a central whitish nodule extending into the subcutis](IDOJ-4-68-g002){#F2}

![Photomicrograph showing uniform population of densely packed spindle cells arranged in storiform pattern and diffuse infiltration of subcutaneous fat producing honey comb pattern. (H and E, ×100)](IDOJ-4-68-g003){#F3}

DFSP is a relatively infrequent, indolent, and low-to-intermediate grade malignant dermal tumor characterized by its locally infiltrative and recurring properties, mostly presenting in the 3^rd^ or 4^th^ decades of life with slight male preponderance.\[[@ref1]\] It accounts for \<0.01% of all malignancies and \<0.1% of all the cutaneous neoplasms, with reported incidence being 0.8 cases per million-persons an year.\[[@ref2][@ref3]\]

Clinically, the malignancy most commonly presents as a painless and a slow-growing subcutaneous polypoidal mass, usually less than 5 cm in size.\[[@ref4]\] Radiologic investigations are not used routinely for the diagnosis as they have typical clinical appearance and superficial location. Radiologic investigations in the form of chest X-ray have a role to detect pulmonary metastasis. Most of the biopsies are taken during its nodular stage so the specimen is grossly received as a solitary grayish white polypoidal mass involving the skin and subcutaneous tissue. On light microscopic examination, the pathology is primarily present in the dermis with irregular lace-like infiltration into the subcutis. The tumor consists of monomorphic population of cylindrical fibroblast arranged distinctly in a monotonous, storiform pattern surrounding an inconspicuous vasculature.

The differential diagnosis includes other fibrohistiocytic neoplasms, atypical fibrosarcoma, dermatofibrosarcoma, infantile myofibromatosis, nodular fasciitis, keloid, and hypertrophic cicatrix; all of which may have similar morphologic findings. Immunohistochemistry reveals CD34 positivity in cases of DFSP, whereas other fibrohistiocytic lesions are negative in CD34 expression.

Radical wide local excision of the tumor along with surrounding area and subcutaneous tissue is the mainstay of treatment to avoid local recurrence.\[[@ref5]\] To achieve negative resection margins and preserve uninvolved tissue, use of Mohs micrographic surgery is suggested by some authors.\[[@ref6]\] There are also recent reports of the role of postresection radiotherapy.\[[@ref7]\] It is imperative to follow up these patients over a long time even after excision.

**Source of Support:** Nil

**Conflict of Interest:** None declared
