Myxoid Adrenocortical Adenoma: Magnetic Resonance Imaging and Pathology Correlation
A 74-year-old female was admitted to our hospital for an evaluation of diffuse abdominal pain. She had a history of hypertension with antihypertensive treatment medication. The results of a physical examination were unremarkable. Laboratory tests, including a full blood count, urea and electrolyte measurements, were within normal ranges.\nA contrast-enhanced CT scan of the abdomen during the portal venous phase demonstrated a well-circumscribed, 6-cm, ovoid-shaped, heterogeneously enhancing mass in the right adrenal gland. Thereafter a MR imaging was performed and a smooth, ovoid-shaped mass in the right adrenal gland with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images similar to that of fluid was revealed (). Signal loss on out-of-phase images compared with that on in-phase images were not observed in the tumor (). The enhancement pattern was early heterogeneous and showed a delayed progressive enhancement (). The mass showed hyperintensity on high b-value (1000 s/mm2) diffusion weighted MR images, but the corresponding high apparent diffusion coefficient value confirmed that the hyperintensity on diffusion-weighted MR images represented T2 shine-through rather than restricted diffusion ().\nThe serum and urine marker levels, including those of metanephrines, cortisol, aldosterone and catecholamine, as well as the results of the 24-hour urine collection for vanillylmandelic acid for the detection of a hormonally active tumor were in the normal range.\nThe patient underwent a right adrenalectomy in the operating room.\nOn the cut section, the tumor measured 6.0 × 4.7 × 1.6 cm, was well-circumscribed, a yellow-greenish mass and had a gelatinous consistency (). Microscopically, more than 90% of the tumor mass were characterized by a myxoid background containing anastomosing cords and tubules of tumor cells (). Most of the tumor cells had a uniform polygonal shape with a distinct cell border. Neither mitotic figures nor necrosis were observed as well as no evidence of vascular or capsular invasion. The final pathologic diagnosis was myxoid adrenocortical adenoma.