Extra-Adrenal Myelolipoma: A 25-Year Review of Epidemiology in a Multihospital System. (21st September 2018)

• Record Type: Journal Article
• Authors: Mahabir, Roshan; Khandakar, Binny; Dhorajiya, MBBS, Poojaben; Fan, Wen; Sharabi, Abdelsalam
• Is Part Of: American journal of clinical pathology. Volume 150(2018)Supplement 1
• Page Start: S106
• Page End: S106
• Publication Date: 2018-09-21
• Subjects: Diagnosis, Laboratory -- Periodicals; Pathology -- Periodicals; 616.07
• DOI: 10.1093/ajcp/aqy097.256
• Languages: English
• ISSNs: 0002-9173

Abstract

Abstract: Objectives: Myelolipomas are rare benign neoplasms comprising both mature adipose tissue and myeloid elements. While the adrenals are the most common site of occurrence, extra-adrenal presentations are exceedingly rare, with only a few presented as case reports. Methods: A 25-year retrospective, semi-quantitative study (2017-1992) was conducted using the pathology database search for all myelolipoma cases within all the hospitals of our system. The resulting data were evaluated for clinicopathological parameters: site of occurrence, presenting symptoms, sex predilection, and age distribution. Results: A total of 44 cases were identified, of which 29 (65.9%) were adrenal and with 15 (34.1%) cases of extra-adrenal myelolipoma. The most common location of extra-adrenal myelolipoma was retroperitoneal (53.3%), kidney (20.0%), and presacral, pelvic, omentum, and gallbladder each presenting with equal distribution (6.7%). The presenting complaint primarily reflected the benign aspect of the neoplasm with "mass" or "benign tumor" representing 86.6% of the primary complaints and "carcinomatosis" and "cholecystitis" representing 6.7% each, where myelolipoma was an incidental finding during surgery for another condition. There was a slight female predominance of extra-adrenal myelolipoma (F = 8, M = 7; F:M 1:1.14) with an earlier age of diagnosis and wider age range for presentation in women (F, 55 [30–76]; M, 66.25 [56–71]). There was only one case of bilateral retroperitoneal myelolipoma, which presented in a 30-year-old female. In the cases where immunohistochemistry was performed, the results showed that factor VIII highlighted megakaryocytes, E-cadherin was expressed in nucleated red blood cells, and myeloperoxidase was positive in myeloid elements. Conclusion: Myelolipoma is rare benign tumor. Most myelolipomas are found within the adrenal, with retroperitoneal and kidney as other common sites of occurrence. All sites of myelolipoma have a female predominance with a younger age at presentation and wider age range, and the tumor usually presents as an incidental finding. Immunohistochemistry reflects the myeloproliferative aspect of the tumor.