Two case reports of bilateral adrenal myelolipomas

Figure 1 Diagnostic imaging and pathohistological examination results of patient A. A-D: Magnetic resonance imaging (MRI) results of bilateral adrenal myelolipomas before the first surgical procedure; A and B: 84 mm diameter circular mass (white arrow) with unequal signals on both T1 and T2 weighted MRI scans in the left adrenal gland (short T1 weighted mixed with longer T2). The mass has a clear boundary. An increased T2 signal can be seen within it; C: That an uneven T1 signal (which includes lipid signal) inside the mass reduces on anti-phase gradient echo T1WI in the left adrenal gland (white arrow). A reduced T1 signal intensity is seen on fat-suppressed image; D: There is no contrast enhancement in most part of the mass on dynamic contrast-enhanced MRI (white arrow). Separation of the lower composite signals shows the delayed linear enhancement pattern; E and F: Computed tomography scan results of the patient before the second surgical procedure. A circular mass (white arrow) with clear boundary has mixed low-density signals with the average absorption values of 7-13 Hu in the right adrenal gland. Separation of the lower composite signals shows no contrast enhancement in the mass; G and H: The adrenal myelolipomas observed on H and E stained sections. Tumor-like masses of extramedullary hematopoietic tissue is composed of adipose cells (red arrow) and hematopoietic cells (green arrow). Fat vacuoles can be seen in adipose tissue. Among adipose cells, there are medullary cells, megakaryocytes, erythrocytes and lymphoid cells with different maturity levels among fat cells. Normal adrenal gland tissue (black arrow) is surrounded by adrenal myelolipoma.

Figure 2 Diagnostic imaging and pathohistological examination results of patients B. A-C: Magnetic resonance imaging (MRI) results of adrenal myelolipomas (MRI scans were performed during the period between the first and the second surgical procedures). A 66 mm diameter circular mass (white arrow) with clear boundary shows mixed signals on T1 and T2 weighted MRI scans (short T1 mixed with slightly longer T2) in the left adrenal gland. The lesion is characterized by decreased T1WI signal intensity in the antiphase (out-of-phase); D: The histopathological features of the right adrenal myelolipoma that was excised in the first surgical procedure (stained with H and E); E and F: The histopathological features of the left adrenal myelolipoma that was removed in the second surgical procedure (stained with H and E). Tumor-like masses of extramedullary hematopoietic tissue is composed of adipose cells (red arrow) and hematopoietic cells (green arrow). Normal adrenal gland tissue (black arrow) is found to be surrounded by adrenal myelolipoma.