Laparoscopic resection of a large adrenal myelolipoma: a case report
- 3.1k Downloads
A 53 year man presented with pain right upper quadrant for seven months. On evaluation he was found to have a large right adrenal myelolipoma. Laparoscopically by transperitoneal right flank approach this was removed. Postoperative recovery was uneventful. Operative specimen's histopathological examination confirmed the diagnosis of adrenal myelolipoma.
KeywordsInferior Vena Cava Hounsfield Unit Glimepiride Laparoscopic Adrenalectomy Adrenal Carcinoma
Adrenal myelolipoma is a rare benign tumour of the adrenal. Most of the time these tumours are asymptomatic. When they are symptomatic they usually present with pain abdomen. Surgery is indicated when the tumour is symptomatic or there is suscpicion of malignancy. Traditionally laparoscopic removal of adrenal tumour of more than 5 cm-6 cm size is contraindicated . Here we removed an 11 cm myelolipoma by laparoscopy without complications.
Myelolipomas are well-circumscribed lesions that contain mature adipose tissue intermixed with mature myeloid elements. The adrenal gland is the most common site, but myelolipomas also occur rarely in extra-adrenal locations . The etiology still remains unknown. Some reports suggested endocrine dysfunction can be the etiology of adrenal and extra-adrenal myelolipoma. Cushing's syndrome, Addison's disease, adrenal hyperplasia, and chronic use of exogenous steroids have been reported in association with myelolipoma [2, 3, 4]. Injecting pituitary extract subcutaneously into experimental rats can induce myelopoiesis [2, 5]. Metaplasia of the reticulo-endothelial cells of blood capillaries in the adrenal gland in response to stimuli such as infection, stress or necrosis has been proposed in pathogenesis of myelolipomas .
Myelolipomas of the adrenal and extra-adrenal gland are usually asymptomatic but larger lesions can cause symptoms from mass effect or haemorrhage [6, 7, 8, 9]. Symptomatic tumours need surgical resection. They are often found incidentally on radiographic studies . Autopsy studies have reported the incidence of myelolipomas as 0.2% in the general population . Characteristic appearances on CT scan and MRI scan of adrenal myelolipoma exclude extensive metabolic workup or surgical exploration . The Hounsfield Unit (HU) is valuable in this regards as it quantify the pixel value of a CT scan area so that the radiologist can compare the composition of one tissue with that of another . The lesion is typically seen as a well-encapsulated, heterogeneous suprarenal mass of low density (less than -30 HU equivalent to mature fat) interspersed by denser myeloid tissue on the CT scan . Large myelolipomas may be confused with necrotic adrenal carcinoma . Other differential diagnoses are retroperitoneal liposarcoma and leiomyosarcoma . It has been found that adrenal malignant neoplasms are usually larger than 6 cm . So the recommendation for incidentally detected asymptomatic adrenal tumour of more than 6 cm is surgical removal . In this case the Hounsfield Unit of the lesion on CT scan was suggestive of myelolipoma, but his tumour was symptomatic as well as larger than 6 cm.
If laparoscopic expertise is available then the excision is done laparoscopically. Previously it was thought to be a contraindication for laparoscopic approach when the tumour size exceeds 5 cm - 6 cm. But several recent studies have shown that laparoscopic approach is technically feasible, safe and comparable with open approach in these patients [15, 16].
Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
- 1.Chow GK, Blute ML: Surgery of the adrenal glands. Campbell-Walsh Urology. Edited by: Wein AJ. 2007, Philadelphia: Saunders-Elsevier, 1868-1888. 9Google Scholar
- 12.Vaughan ED, Blumenfeld JD: Pathophysiology, Evaluation and medical management of adrenal disorders. Campbell-Walsh Urology. Edited by: Wein AJ. 2007, Philadelphia: Saunders-Elsevier, 1821-1867. 9Google Scholar
- 13.Miraldi F, Sims MS, Wilson EJ: Imaging principles in computed tomography. CT and MR imaging of the whole body. Edited by: Haaga JR, Lanzieri CF, Gilkeson RC. 2003, St Louis: Missouri, 2-36. 4Google Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.