Rare Intravascular Involvement of Pleomorphic Dermal Sarcoma Seen During Mohs Micrographic Surgery

Area of Science:

• Dermatopathology
• Surgical Oncology
• Oncologic Pathology

Background:

• Pleomorphic dermal sarcoma (PDS) and atypical fibroxanthoma (AFX) are rare mesenchymal tumors with overlapping features.
• Distinguishing PDS from AFX is critical due to PDS's higher potential for recurrence and metastasis.

Purpose of the Study:

• To present a case highlighting the diagnostic challenges and importance of differentiating PDS from AFX.
• To illustrate how intraoperative findings during Mohs surgery can aid in distinguishing these tumors.

Main Methods:

• Histopathological examination of biopsy specimens.
• Immunohistochemistry panel for differential diagnosis.
• Mohs micrographic surgery with en face processing for intraoperative assessment.

Main Results:

• Initial biopsy suggested AFX, but deep invasion into subcutaneous tissue and galeal aponeurosis was observed during Mohs surgery.
• En face processing during Mohs surgery revealed intravascular involvement, confirming the diagnosis of PDS.
• PDS diagnosis was established based on deep invasion and intravascular involvement, features not typically seen in AFX.

Conclusions:

• Deep invasion and high-grade features like intravascular involvement are key indicators of PDS.
• Mohs micrographic surgery provides valuable intraoperative information for accurate tumor diagnosis and management.
• Accurate differentiation between PDS and AFX is essential for appropriate patient monitoring and treatment planning.