A Rare Case of Rapidly Enlarging Myelolipoma in Sickle Cell Disease

Abstract

Objective: Adrenal myelolipoma (AM) is a benign tumor composed of mature fat cells and hemopoietic elements. Most AMs are incidental findings on imaging and clinically asymptomatic. The purpose of this case report is to describe a rare case of AM and explore its clinical manifestations, imaging features, and treatment. Methods: In this study, we report a case of a rapidly growing right AM in a patient with uncontrolled hemoglobin sickle cell disease. A 38-year-old male presented to our institution's endocrine surgery clinic for evaluation of an enlarging right adrenal mass. This mass was incidentally found during an abdominal ultrasound performed for transaminitis and thrombocytopenia. Patient was asymptomatic without any abdominal discomfort, back pain, nausea, or vomiting. Results: Patient was lost to follow up until 2018. Follow-up computed tomography scan in 2018 showed the right adrenal mass measuring 12.3 cm in greatest dimension with significant macroscopic fat. Given the imaging features, AM was the presumed diagnosis. However, with a medical history of uncontrolled sickle cell disease, extra-medullary hematopoiesis and rapidly growing liposarcoma could not be ruled out. Surgical excision was performed due to size and significant tumor growth. Diagnosis was confirmed with histopathology and revealed myelolipoma. Conclusion: Image characteristics can be helpful in diagnosis of AM; however, the appearance of this lesion on computed tomography can be similar to other adrenal gland pathologies such as liposarcoma and mass-forming extramedullary hematopoiesis. Percutaneous needle biopsy may be indicated if the diagnosis remains unclear.

Case Report of a Giant Adrenal Myelolipoma in a Patient with Sickle Cell Anaemia

“…Many cases of adrenal myelolipoma have been reported in sickle cell disease (SCD) and thalassemia, but the pathogenesis is not clear [6,7]. However, it is postulated that the persistent anaemia in SCD may be responsible for the stimulation of metaplasia in the haemopoietic elements sited in the adrenal stroma, leading to rapid tumour growth [7,8]. This may explain why our patient developed the tumour in childhood,…”

“…Mass-forming extramedullary haematopoiesis (EMH) is another type of fatcan occur in patients with haematologic disorders [8]. EMH is a physiological response secondary to insufficient blood cell production and bone marrow function and usually occurs in the reticulo-endothelial system outside the bone marrow.…”

“…EMH is a physiological response secondary to insufficient blood cell production and bone marrow function and usually occurs in the reticulo-endothelial system outside the bone marrow. However it rarely occurs in the adrenals [8,9]. The size of adrenal myelolipomas is variable and can range from a few millimetres to greater than 10 cm, where they are termed giant adrenal myelolipomas [2].…”

“…CT is the preferred imaging modality for the diagnosis of adrenal myelolipoma [2]. It is also the most sensitive for detecting haemorrhage, which may be hyper to hypodense depending on the age of evolution [2,8]. On MRI, the predominantly fatty areas in myelolipoma appear hyperintense on T1 MRI images and intermediate to hyperintense on T2 [2].…”