Heterotopic submandibular gland with herniation through the mylohyoid boutonnière: a unique radiological case

To describe a rare case of heterotopic submandibular gland (SMG) tissue herniating through the mylohyoid boutonnière into the anterior submandibular space, diagnosed using imaging, and to provide insights into its clinical implications.

A 59-year-old male with a history of smoking and type 2 diabetes presented with new-onset hoarseness. Imaging, including contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), was performed. The lesion's imaging characteristics, location, and tissue composition on CT and MRI were analyzed, and differential diagnoses were considered.

CT and MRI revealed a well-defined soft tissue lesion in the right anterior submandibular space, exhibiting features consistent with ectopic SMG tissue. On MRI, the lesion was iso- to slightly hyperintense compared to surrounding muscle tissue and showed ductal structures leading to the sublingual space, with a discontinuity in the mylohyoid muscle. No malignancy or other pathologies were identified, and the patient's hoarseness improved with treatment for dyspepsia.

This case highlights the diagnostic value of imaging in identifying rare anatomical anomalies like heterotopic SMG with herniation through the mylohyoid boutonnière. Accurate diagnosis can prevent unnecessary procedures and guide appropriate management.