Adenomatoid Hyperplasia Requiring Differential Diagnosis From Malignant Neoplasms: A Report of Two Cases

Adenomatoid hyperplasia (AH) of the minor salivary glands is a rare, benign hyperplastic lesion that typically arises in the oral mucosa, most commonly in the hard or soft palate. AH generally presents as a painless mass covered with normal mucosa. AH can mimic the clinical course of malignant salivary gland tumors, making diagnosis challenging. This series presents two cases of AH arising in unusual sites, the buccal mucosa and sublingual caruncle, which were initially suspected of being malignant tumors and were evaluated using multimodal imaging. Patient 1, a 76-year-old female, presented with a buccal mass of 6 × 8 mm in size that increased in size over time and was eventually diagnosed with AH with sialadenitis. Patient 2, an 85-year-old male, presented with an indurative mass of 4 × 4 mm in size near the sublingual caruncle, later diagnosed with AH along with sialadenitis. Both patients underwent excisional biopsy with a safety margin comparable to that for malignant tumors. Each patient is now being monitored regularly without recurrence. Our patients underwent multiple imaging modalities prior to the surgery; however, they underscored the limited utility, especially in evaluating small lesions. Therefore, histopathological examination remains crucial for its definitive diagnosis. AH can present in unusual locations and mimic malignancy during its clinical course, especially when accompanied by inflammation, emphasizing the importance of its differential diagnoses. Through our case series, we highlighted that excisional biopsy is an effective strategy, and histopathological examination is essential for accurate diagnosis.