Carcinoma ex pleomorphic adenoma (Ca ex PA) is a rare salivary gland malignancy arising from a previously benign pleomorphic adenoma. With a similar clinical presentation to benign salivary gland tumors and a variety of histologic variants, diagnosis is often difficult. Diagnosis of malignancy and thus surgical treatment is largely based on pathologic and radiographic features. The malignant component of Ca ex PA can take on many forms to include poorly differentiated adenocarcinoma not otherwise specified, salivary duct carcinoma, squamous cell carcinoma, mucoepidermoid carcinoma, adenoid cystic carcinoma, myoepithelial carcinoma, and epithelial myoepithelial carcinoma. A case report of myoepithelial carcinoma ex pleomorhpic adenoma is explained here. This case highlights the challenges in clinical and pathologic diagnoses and provides an overview of surgical treatment in these rare and potentially aggressive tumors.

A 25-year-old male was referred to the Radiology Department with new onset of right upper quadrant and epigastric abdominal pain. He had no past medical or surgical history. Physical exam was unremarkable. The patient underwent computed tomography (CT), fluoroscopic upper gastrointestinal (GI) evaluation, endoscopic ultrasound (EUS), and positron emission tomography (PET) evaluation, revealing the presence of a heterogeneous esophageal mass. In light of imaging findings and clinical workup, the patient was ultimately referred for thorascopic surgery. Surgical findings and histology confirmed the diagnosis of esophageal heterotopic pancreas.