Recurrent Pleomorphic Adenoma: A Rare Case with Diagnostic Challenges and Dermatologic Implications

Summary: The poster presents a case study on Recurrent Pleomorphic Adenoma (PA), a typically benign salivary gland tumor that can pose diagnostic challenges, particularly for dermatopathologists. It describes a 33-year-old female with a history of PA in the left submandibular gland that was excised 15 years prior, now presenting with a multinodular neck mass. Imaging revealed multiple soft tissue nodules, raising concerns about recurrence and potential malignant transformation. Key Findings: Histopathology: Microscopic examination showed multiple round nodules with characteristic features of PA but without malignant cytologic changes. Diagnosis & Management: Core biopsy confirmed recurrent PA. The patient underwent modified radical neck dissection, and tumor nodules were found at the resection margins, prompting a referral for adjuvant therapy. Discussion: Despite its benign histology, recurrent PA can behave unpredictably. Literature suggests that 3% of recurrent cases undergo malignant transformation, and those with multiple metastases have a worse prognosis. Accurate differentiation from carcinoma ex-pleomorphic adenoma or metastasizing PA is critical for treatment planning. Conclusion: Dermatopathologists must employ detailed imaging, histologic sampling, and clinical correlation to distinguish benign recurrent PA from malignant cases, influencing decisions on surgery and adjuvant therapy. This case underscores the importance of vigilant long-term follow-up in patients with recurrent PA to manage potential malignant transformation or metastasis.