Clinical course of adrenal myelolipoma: A long-term longitudinal follow-up study

Abstract

Objective: We aimed to describe clinical course of myelolipoma and to identify predictors of tumour growth and need for surgery. Design: A retrospective study. Patients: Consecutive patients with myelolipoma. Results: A total of 321 myelolipomas (median size, 2.3 cm) were diagnosed in 305 patients at median age of 63 years (range, 25‐87). Median follow‐up was 54 months. Most myelolipomas were incidentally detected (86%), whereas 9% were discovered during cancer staging and 5% during workup of mass effect symptoms. Thirty‐seven (12%) patients underwent adrenalectomy. Compared to myelolipomas <6 cm, tumours ≥6 cm were more likely to be bilateral (21% vs 3%, P < .0001), cause mass effect symptoms (32% vs 0%, P < .0001), have haemorrhagic changes (14% vs 1%, P < .0001) and undergo adrenalectomy (52% vs 5%, P < .0001). Among patients with ≥6 months of imaging follow‐up, median size change was 0 mm (−10, 115) and median growth rate was 0 mm/y (−6, 14). Compared to <1 cm growth, ≥1 cm growth correlated with larger initial size (3.6 vs 2.3 cm, P = .02), haemorrhagic changes (12% vs 2%, P = .007) and adrenalectomy (35% vs 8%, P < .0001). Conclusions: Most myelolipomas are incidentally discovered on cross‐sectional imaging. Myelolipomas ≥6 are more likely to cause mass effect symptoms, have haemorrhagic changes and undergo resection. Tumour growth ≥1 cm is associated with larger myelolipoma and haemorrhagic changes. Adrenalectomy should be considered in symptomatic patients with large tumours and when there is evidence of haemorrhage or tumour growth.