Endocrine Abstracts

Introduction: Primary acinic cell carcinoma (ACC) is an uncommon salivary gland (SG) tumor, making up 1–3% of all SG neoplasms, more frequent in women, at 40–60 year old. The cause is still unknown and the only well-established risk factor is ionizing radiation. ACC metastasize in 10–15% of the cases, 35% tends to recur and the rate of disease-associated death is about 16%. Surgical resection is the mainstay treatment, but radiation therapy may be used in some cases and, more rarely, chemotherapy in advanced ACC.

Case Report: We describe a case of a 46-year-old man referred by paresthesias, general malaise and hypokalemia of 2.5 mEq/l. The patient had a history of pericentimetric nodule in the left submandibular gland diagnosed 1 year before, hypertension and dyslipidemia diagnosed 4 months before and also new-onset diabetes mellitus (DM) diagnosed in the previous month. Ambulatory analysis showed endogenous hypercortisolism, and he was admitted to the endocrinology department for further investigation. Hormonal study revealed: ACTH 206.8 (<63.3) ng/l, cortisol 30.1(6.2–19.4) μg/dl; cortisoluria, 24-hour salivary cortisol and low-dose dexamethasone suppression test confirmed Cushing’s syndrome(CS); high-dose dexamethasone suppression test was compatible with ectopic CS. Initial imaging study found several hepatic nodular lesions, suggestive of secondary lesions by neoplastic process. Investigation was continued, with imaging and cytological documentation of probable primary parotid malignancy with hepatic metastasis. Octreoscan revealed increased uptake in the parotid gland and mild expression in hepatic metastasis. No uptake was observed in PET-Gallium. The patient underwent right parotidectomy, with the histological diagnosis of ACC, pT3NxR1, with no neuroendocrine differentiation, Ki67 70%. Imaging reevaluation revealed disease progression, with pulmonary and bone metastasis, and the patient started chemotherapy. Meanwhile, hypercortisolism was controlled with metyrapone (3 g/day), ketoconazole (400 mg/day) and lanreotide (120 mg/month).

Conclusion: The authors present a very rare case of ACC, with paraneoplastic CS and aggressive behavior, presenting significant diagnostic and management challenges.