Dermatofibrosarcoma Protuberans Arising in a Digit: A Case Report.

Area of Science:

• Oncology
• Dermatopathology
• Medical Genetics

Background:

• Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing soft tissue sarcoma.
• DFSP typically presents on the trunk and extremities.
• DFSP is characterized by a specific genetic translocation, t(17;22).

Purpose of the Study:

• To report an extremely rare case of DFSP occurring on a digit.
• To emphasize the diagnostic challenges and importance of accurate identification of DFSP in unusual locations.
• To highlight the role of advanced molecular techniques in confirming DFSP diagnosis.

Main Methods:

• Clinical and histological examination of an atypical CD34-positive tumor.
• Differential diagnosis including similar entities.
• Fluorescence in situ hybridization (FISH) to detect the COL1A1-PDGFB translocation, t(17;22)(q22;q13).

Main Results:

• A CD34-positive tumor on the digit was identified in a 43-year-old male.
• FISH analysis confirmed the characteristic t(17;22) translocation, confirming the diagnosis of DFSP.
• The tumor exhibited features that initially suggested other differential diagnoses.

Conclusions:

• DFSP can exceptionally arise on digits, presenting a diagnostic challenge.
• CD34 positivity in acral tumors warrants consideration of DFSP in the differential diagnosis.
• Cytogenetic analysis, specifically FISH for the t(17;22) translocation, is crucial for definitive DFSP diagnosis and guiding treatment.