Lipomatous tumours in adrenal gland: WHO updates and clinical implications

Abstract

Adrenal lipomatous tumour is a group of adrenal tumours with a significant component of adipose tissue. According to the current World Health Organization (WHO) classification of tumours of endocrine organs, adrenal myelolipoma is the only entity amongst the group of tumours being described. In the literature, other more recently documented adrenal lipomatous tumours included 24 lipomas, 32 teratomas and 16 angiomyolipomas. Rare fatty tumours of the adrenal gland comprised liposarcoma, hibernoma, adrenocortical tumours with fat component and rare adrenal tumours with fat component. Myelolipoma comprises approximately 3% of primary adrenal tumour. It is noted more commonly in females and in the right adrenal gland. Approximately 40 bilateral myelolipomas were reported. The tumour is most frequently recorded in patients between fifth and seventh decades of life. Adrenal lipomas are often seen in males and in the right adrenal gland. They were commonly noted in patients in the sixth decade of life. The diagnosis could only be possible on examination of the surgically removed specimen. Adrenal teratomas were more common in females and with a bimodal age distribution. Slightly over 60% of the patients with adrenal teratoma are symptomatic. Adrenal angiomyolipomas were often symptomatic, more common in females and in the fifth decades of life. To conclude, adrenal lipomatous tumour is uncommon. They are often benign and non-functional. It is important to recognize the features of this group of lipomatous tumours in the adrenal gland as they are being detected on increasing incidence as a result of the wide-spread use of modern imaging modalities.

Adrenal myelolipoma: a comprehensive review

“…The laterality of tumors corresponded to previous findings describing that right-sided myelolipomas are more frequent [1,20,39]. In our analysis, 260 tumors (59.2%) were on the right side, 111 on the left side (25.3%), while 54 tumors (12.3%) were bilateral (no data were available in 15 cases).…”

“…Among these 211 (48.6%) were female and 223 (51.4%) male, thus no gender difference can be established. In contrast, Lam reported a female preponderance based on two Chinese studies [39].…”

“…The differential diagnosis of adrenal lipoma is only possible by the histological examination of the removed tumor, as it contains no myeloid elements. Adrenal lipoma is extremely rare (only 24 well-documented cases in the literature), and being also a benign tumor [39], its differential diagnosis from myelolipoma cannot be regarded as clinically relevant.…”

Are there any Connections between Adrenal Myelolipoma and Hypertension?

“…Adrenal myelolipoma(AML) is generally considered a non-functional benign tumor originated from adrenal cortex, made up of variable proportion of mature fat and hematopoietic tissues [1]. The number of case-reports about AML has considerably increased in recent years, which may be related to the development and wide application of imaging techniques, resulting in an increase in detection of adrenal incidentaloma including AML [2].…”

“…The number of case-reports about AML has considerably increased in recent years, which may be related to the development and wide application of imaging techniques, resulting in an increase in detection of adrenal incidentaloma including AML [2]. Female patients are more common and the predilection age is 50-70 years old, with right lesions more prevalent than those in the left [1,3]. Initially, the neoplasm is asymptomatic, which is discovered during routine physical examination accidentally.…”