The Role of CD34 and D2-40 in the Differentiation of Dermatofibroma and Dermatofibrosarcoma Protuberans.

OBJECTIVE: Dermatofibroma (DF) is a benign fibrohistiocytic tumor whereas dermatofibrosarcoma protuberans (DFSP) has intermediate malignant potential. CD34 is the most commonly used antibody in differentiating these tumors. Various studies have stated the rates of D2-40 expression as 0-50% in DFSPs and 86-100% in DFs. Our aim in this study was to determine the expression of CD34 and D2-40 in DFs and DFSPs and the possible use of D2-40 in the differential diagnosis of these lesions. MATERIAL AND METHOD: This is a retrospective study including 30 DF and 15 DFSP cases which were reevaluated for epidermal changes, the presence of a transmission zone (Grenz zone), infiltration of soft tissues, infiltration pattern and histologic subtypes in addition to cellular pleomorphism, nuclear atypia, and necrosis. A manual immunohistochemistry procedure was performed with D2-40 and CD 34 antibodies using a representative paraffin block. RESULTS: The average age was 37.36 and 42.86 years in the DF and DFSP cases. The average diameter was 0.9 and 5.03 cm, respectively, for the DFs and DFSPs. There was a significant correlation between the two entities for sex, localization and diameter of the lesion. A significant difference was found between the positivity of CD34 and D2-40 in DFs and DFSPs. CONCLUSION: Additional immunohistochemical markers may be needed in DFs with CD34 positivity. Our results showed the additional helpful role of this marker in problematic cases.

Synovial sarcoma of the infratemporal fossa with intracranial extension.

Synovial sarcomas (SS) account for 7-8% of soft-tissue cancers and 3-5% of all cases with head and neck involvement. Synovial sarcoma of the infratemporal fossa is very rare In this article, we report the fourth case of SS of infratemporal fossa and the first case with intracranial extension via the foramen ovale. A 31-year-old man admitted with a one-year history of intense pain in his right jaw. On physical examination, there was only hyperesthesia over the right mandible side. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a mass in the infratemporal fossa and intracranial extension from the foramen ovale. The mass was surgically removed en bloc. Postoperative pathological examination reported the mass as a biphasic-type synovial sarcoma. The patient who received postoperative chemoradiotherapy had no recurrent disease for one year. The patient is still being followed in our clinic.