Endocrine Abstracts

Adrenal carcinoma is a very rare malignancy accounting for 0.05–0.2% of all cancers, with an incidence 0.5–2/10⁶.

We present the case of a 60 year old woman with impaired fasting glucose and hypertension, who was incidentally diagnosed, after a non-enhanced abdominal CT, with a right adrenal tumor of 4.5/6 cm. The mass was described as having smooth borders, and a heterogeneous aspect including solid parts, necrotic areas and 1 microcalcification. Laboratory findings revealed a low-normal ACTH (8.2 pg/mL, nv: 7.2–63.3), normal morning serum cortizol (13.4 μg/dl, nv: 3.7–19.4) with insufficient suppresion after the over night and the two-day low dose dexamethasone tests (3.3/2.7 ug/dl). The DHEA-S was low (15.9 ug/dl nv: 29,7–182) and testosterone normal. We excluded a pheocromocytoma: normal CgA, plasmatic metanephrines and normetanephrines. The patient also presented chronic autoimune thyroiditis with hypothyroidism and a slightly high CEA, probably due to the hypothyroidism. She was given 50 ug LT4/day.The MRI exam showed a T2 hyperintense mixed right adrenal tumor, with apparent diffusion coefficient (ADC) and heterogeneous enhancement seen with administration of gadolinium- both specific for benign structures.The patient was operated. The histopathology exam showed an adrenal carcinoma (pT3NxMx) with a Weiss Score of 4 and IHC was positive for Vimentin, inhibin, sinaptofizin, Chromogranin. Ki-67 was 5–10%. Postoperatory, the patient did not present adrenal insufficiency and was reffered to the Oncology ward for initiation of Mitotan therapy.

Conclusions: The DWI/ADC MRI sequences- have no diagnostic utility in differentiating between lipid-rich and lipid-poor adenomas and between benign and malignant nodules and should not be used for this purpose. Malignant nodules may have MRI contrast enhancement suggestive for benign tumors. The best tool for differentiating between benign and malignant nodules remains enhanced CT by comparing the attenuation value before and after contrast administration.