Cytologic diagnostic pitfall of dermatofibrosarcoma protuberans masquerading as primary parotid tumor: A case report

Abstract

We report the cytology of a rare case of dermatofibrosarcoma protuberans (DFSP) involving the parotid region. Our patient was a 55-year-old female who presented with a swelling in the right parotid region, which was clinically interpreted as a "recurrent parotid tumor." Fine needle aspiration revealed a moderate cellular yield with spindle cell component, seen discretely as well as, embedded loosely within a fibrillary magenta matrix. A few cellular spindle cell fascicles and several discrete, naked, spindly nuclei were also noted. Neoplastic cells exhibited a minimal pleomorphism with a relatively bland chromatin and inconspicuous nucleoli. A differential diagnosis of the benign spindle cell tumor/low, or intermediate grade myxoid, spindle cell sarcomas was considered. Owing to its clinical presentation simulating a parotid tumor, possibility of "spindle cell myoepithelioma" was suggested. However, histopathologic examination with immunohistochemistry showed it to be a DFSP. A precise diagnosis of DFSP is not always possible on cytology alone. Owing to its location, as well as the spindle cell morphology, DFSP occurring in the parotid region is likely to be mistaken for a spindle cell myoepithelioma, in which case, an appropriate panel of immunomarkers is required for resolving the diagnostic dilemma.

Epidemiology of Dermatofibrosarcoma Protuberans in Alberta, Canada, from 1988 to 2007

“…Thus it is possible that the ACR captured a greater proportion of DFSP cases in the Alberta population than studies reporting a lower incidence . Third, the diagnosis of DFSP is not always straightforward, particularly if presenting in an uncommon location or biopsied using fine needle aspiration . In one review of the cytologic smears of 12 patients with primary, recurrent, or metastatic DFSP, only six were given the correct diagnosis .…”

“…8 Third, the diagnosis of DFSP is not always straightforward, particularly if presenting in an uncommon location or biopsied using fine needle aspiration. 22,23 In one review of the cytologic smears of 12 patients with primary, recurrent, or metastatic DFSP, only six were given the correct diagnosis. 22 The most commonly used cellular marker for pathologic diagnosis of DFSP (CD34) was not widely described in the literature as a marker of this tumor until the early to mid-1990s, increasing the possibility of diagnostic inaccuracy before this time 24 Thus, the large discrepancy between the overall incidence obtained in our study and that obtained others could be due to a multitude of factors.…”

Primary sarcomas of the salivary glands: Case series and literature review

“…We next conducted a review of the contemporary literature from January 1990 to July 2010 and identified 170 reported cases of malignant mesenchymal cell tumors of the salivary glands, in addition to the 17 cases in our series. Rhabdomyosarcoma was the most common neoplasm, representing 13% of cases, with a median age at diagnosis of 7 years.…”

A case of aggressive giant dermatofibrosarcoma protuberance occurring in the parotid gland

“…These tumors occur mainly over the trunk and proximal extremities and tend to recur after wide local excision. Parotid gland or parotid region is a very rare site with few published case reports [2].…”

“…Dermatofibrosarcoma protuberans (DFSP) is a relatively uncommon soft tissue neoplasm of intermediate- to low-grade malignancy. The incidence of sarcomas of the major salivary gland appears to be about one-tenth of benign mesenchymal tumors [2,3]. Metastasis occurs rarely.…”