Myxoid adrenocortical adenoma with a pseudoglandular pattern.

Myxoid changes rarely occur in adrenocortical adenomas and carcinomas. Only eight benign tumours with such features have been described thus far, five of which also had a prominent pseudoglandular component. We report an additional pseudoglandular myxoid adenoma of the adrenal gland detected in a 58-year-old male patient who developed mild hypertension. At surgery, a 4-cm mass was resected and found to contain cords and tubules of polygonal cells in a myxoid background. Limited areas of classical adrenocortical adenoma were detected in less than 20% of the tumour area. Lack of atypias and absence of mucin markers, together with an immunophenotype consistent with adrenal tumours (focal cytokeratin, vimentin, synaptophysin and alpha-inhibin immunoreactivities), led to a diagnosis of primary adrenocortical adenoma with an extensive pseudoglandular myxoid pattern. However, the differential diagnosis from metastatic well-differentiated adenocarcinomas, chordomas and retroperitoneal myxoid mesenchymal tumours (e.g. liposarcoma) may be difficult in the absence of a complete clinical history and a reliable immunoprofile. We strongly recommend staining of any myxoid or glandular tumour of the adrenal gland for alpha-inhibin and synaptophysin (probably the currently best characterised markers of adrenocortical origin) before considering alternative (probably more common) diagnoses of metastatic adenocarcinoma or retroperitoneal tumours localised to the adrenal gland.