Perivascular spread of adenoid cystic carcinoma: a novel imaging sign.

To cite: Kumar S, Hasan R, Paulraj SK, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2015210969 DESCRIPTION A 75-year-old woman presented with a mildly painful mass over her right lower jaw for 3 years. The mass presented as a small nodule and progressively increased to the present size. Additional symptoms included dull aching pain in the right lower jaw for the last 15 years, radiating to the right ear and not related to chewing or salivation, with temporary relief on medications. She reported pain on opening her mouth and had difficulty swallowing. On examination, an oval shaped 3×2 cm tender mass was found overlying the angle of the right mandible. The mass was hard in consistency, with ill-defined margins, and was fixed to the underlying muscle. A few small papillomatous nodules were seen in the overlying skin. There was also fullness in the right floor of the mouth near the region of the opening of submandibular papilla. However, no calculus was palpated on bidigital examination. Ultrasound of the neck revealed a relatively well-defined hypoechoic mass, measuring 2.5×2×1.4 cm, overlying the right angle of the mandible, showing anteromedial extension as a cuff of soft tissue centred on a vessel, extending along the medial margin of the body of the mandible, superficial to the mylohyoid muscle (figure 1A–C). CT scan showed heterogeneous enhancement of the mass lesion located at the angle of the mandible with extension along the submental branch of the facial artery, coursing anterolateral to the right submandibular gland, between the medial margin of the mandible and mylohyoid muscle. There were multiple small enhancing subcutaneous nodules seen in the overlying skin (figure 2A–D). Fine-needle aspiration cytology of the mass revealed features suggestive of adenoid cystic carcinoma (ACC). A complete surgical excision of the mass along with right submandibular gland and supraomohyoid neck dissection was performed. Histopathology findings were consistent with minor salivary gland ACC with perineural and perivascular invasion (figure 3A, B). The skin nodule and its underlying subcutaneous tissue were infiltrated by the tumour. The excised submandibular gland and cervical lymph nodes were free from tumour. CTof the thorax was normal. The patient was diagnosed as minor salivary gland ACC, grade II, mixed pattern, TNM stage T4N0M0 and received postsurgical adjuvant radiotherapy. On 6 months follow-up, the patient remains symptom free.