A 24-year-old female presented with a six-month history of a progressively enlarging mass in the right submandibular region. The swelling had gradually increased in size, prompting medical evaluation.
A 24-year-old female presented with a six-month history of a progressively enlarging mass in the right submandibular region. The swelling had gradually increased in size, prompting medical evaluation. She denied associated pain, dysphagia, odynophagia, respiratory symptoms, or constitutional symptoms such as fever, weight loss, or night sweats. Her past medical history and past surgical history were unremarkable, and she was not taking any regular medications. Family history was negative for malignancies or other significant hereditary diseases.
Laboratory evaluation revealed normal hematological parameters, with a white blood cell (WBC) count of 6.7 × 10⁹/L, a hemoglobin level of 13.6 g/dL, and a platelet count of 297 × 10⁹/L. The erythrocyte sedimentation rate (ESR) was 9 mm/hr, within the normal range. Thyroid function tests were normal, with a thyroid-stimulating hormone (TSH) level of 2.65 µIU/mL and a free thyroxine (FT4) level of 14.9 pmol/L. Renal function was preserved, with a blood urea level of 27 mg/dL and a serum creatinine level of 0.39 mg/dL. Random serum glucose was 106 mg/dL, within the normal range. Viral screening for HIV, hepatitis C virus (HCV), and hepatitis B surface antigen (HBsAg) was non-reactive. Overall, the laboratory findings were unremarkable and showed no evidence of systemic illness.
Ultrasonographic examination of the neck demonstrated a 32 × 23 × 31 mm complex, heterogeneous, predominantly isoechoic, hypovascular mass located along the inferolateral aspect of the right submandibular gland. The lesion exhibited well-defined margins without sonographic evidence of infiltration into the adjacent soft tissues. The right submandibular gland appeared mildly enlarged. Based on the imaging characteristics, further evaluation with contrast-enhanced computed tomography (CT) was recommended, and a dermoid cyst remained within the differential diagnosis. Additionally, multiple bilateral cervical lymph nodes, predominantly within the right cervical chain, were identified. These lymph nodes were variable in size but maintained benign morphological characteristics, including an oval configuration, preserved echogenic fatty hila, and cortical thickness of less than 2 mm. The largest lymph node measured 17 × 5 mm in the right submandibular region, with findings favoring reactive inflammatory lymphadenopathy. The thyroid gland was normal in size and echotexture, with no focal nodules or other sonographic abnormalities. The left submandibular gland and both parotid glands were unremarkable, with no focal lesions identified.
Contrast-enhanced CT of the neck and upper chest demonstrated a well-defined, relatively thick-walled cystic lesion measuring 31 × 30 × 25 mm within the right submandibular region. The lesion displaced and stretched the right submandibular gland anteriorly and contained a fluid–fat level, a characteristic imaging feature highly suggestive of a dermoid cyst. Mild peripheral wall enhancement was observed following intravenous contrast administration; however, there was no enhancing solid component or internal calcification. The remaining major salivary glands were normal in appearance without focal lesions. The pharynx and larynx were unremarkable, with no evidence of a mass lesion, and no oral cavity mass was identified. The thyroid gland was normal in size and morphology without focal abnormalities. No pathologically enlarged cervical lymph nodes were detected. The visualized upper mediastinum and lung apices were unremarkable, and no suspicious osseous lesions were identified. Overall, the radiological findings were consistent with a dermoid cyst of the right submandibular region.
Given the clinical and radiologic findings suggestive of a right submandibular dermoid cyst, the patient underwent surgical excision under general anesthesia. With the patient in the supine position and the neck extended, a transverse skin-crease incision was made approximately 2 cm inferior to the mandibular border. Careful dissection was performed to identify and preserve the hypoglossal and lingual nerves. The cyst was completely excised without rupture, and meticulous hemostasis was achieved. The wound was subsequently closed in anatomical layers. The procedure was completed without intraoperative complications.
Histopathological evaluation of the right submandibular cyst excision specimen revealed a ruptured dermoid inclusion cyst with associated inflammatory changes and foreign body giant cell reaction. The cyst wall was focally lined by benign keratinized stratified squamous epithelium and contained cutaneous adnexal structures within the cyst wall. The cyst lumen demonstrated abundant keratinous debris and hair shaft fragments, consistent with a dermoid cyst. There was associated dense mixed inflammatory cell infiltration, foreign body giant cell reaction, and accumulation of foamy macrophages, reflecting cyst rupture and chronic inflammatory response. No evidence of malignancy was identified.
The patient had an uneventful postoperative recovery following excision of the right submandibular dermoid cyst. There were no intraoperative or immediate postoperative complications, and the surgical wound healed well with no evidence of infection, hematoma, or dehiscence. Function of the preserved hypoglossal and lingual nerves remained intact, with no postoperative neurological deficits noted. The patient was advised routine clinical follow-up, and no further intervention was required following complete excision of the lesion.
