Primary cutaneous adenoid cystic carcinoma of the neck presenting as a rapidly growing posterior triangle neck mass.

A woman in her 70s presented to a tertiary otorhinolaryngology outpatient department with a 25-year history of right-sided subcutaneous neck lesion that had steadily grown over the preceding 6 months, now with skin involvement. The patient was asymptomatic except for some mild tenderness. The 3 × 3 cm mass lay fixed to deep tissues adjacent to the sternocleidomastoid muscle, though no associated lymphadenopathy was found on palpation, with imaging confirming no regional or distant metastases. Biopsy confirmed the lesion to be primary cutaneous adenoid cystic carcinoma, a malignancy not previously described as a primary on the neck, which was treated by wide local excision after multidisciplinary team discussion. The lesion was completely excised with negative margins, and after surveillance over 3 years, the patient is still well with no signs of recurrence.