|Year : 2018 | Volume
| Issue : 4 | Page : 292-294
Giant myelolipoma; benign yet life-threatening!
Pranita Mohanty, Rupanita Biswal, Jhasaketan Nayak
Department of Pathology, IMS and SUM Hospital, Bhubaneswar, Odisha, India
|Date of Web Publication||10-Jan-2019|
Dr. Pranita Mohanty
Department of Pathology, IMS and SUM Hospital, Bhubaneswar - 751 003, Odisha
Source of Support: None, Conflict of Interest: None
Myelolipoma, an incidentaloma, is rarely encountered, especially in adrenal location. Huge myelolipomas are extremely rare and are of surgical emergency. Here we report a 33-year-old male who presented with pain in the right lumbar region with normal complete hemogram and serum hormonal markers. Ultrasonography and contrast-enhanced computed tomography abdomen revealed a huge well-defined homogeneous mass in the right adrenal region which was then removed surgically and histology revealed benign myelolipoma. Myelolipomas are benign and usually asymptomatic. But large lesions may have acute presentation and hence have to be dealt with utmost urgency along with proper imageological evaluation.
Keywords: Adrenal, contrast-enhanced computed tomography, myelolipoma
|How to cite this article:|
Mohanty P, Biswal R, Nayak J. Giant myelolipoma; benign yet life-threatening!. J NTR Univ Health Sci 2018;7:292-4
| Introduction|| |
Myelolipoma is a rare benign tumor accounting for 2.6% of all primary adrenal tumors; it is most commonly seen in the adrenal glands, although extra adrenal locations such as pelvis, mediastinum, retroperitonium, and paravertebral region are also known. In most cases, the lesion is found incidentally, hence incidentaloma. It was initially described by Edgar Von Gierre in 1905, and 24 years later the term “myelolipoma” was coined by Charles Oberling. In the past, these lesions were primarily detected at autopsy (incidence 0.08%–0.4%); however, recently with the widespread use of noninvasive imaging modalities such as ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging, the incidental detection has been more common. The tumor is detected most commonly between the fifth and seventh decade of life, affecting men and women equally. The majority of tumors are unilateral, small, and asymptomatic, but some bilateral myelolipomas have also been described. Small tumors are asymptomatic. Large tumors present with pressure symptoms and abdominal pain, although few may cause spontaneous retroperitoneal hemorrhage. These lesions can be found in normal adrenal glands, in association with endocrine disorders such as Cushing's disease, Addison's disease, congenital adrenal hyperplasia, and hyperaldosteronism, or with other tumors such as ganglioneuroma and Hodgkin's lymphoma.,
| Case Reports|| |
A 33-year-old male presented with nonspecific, moderate pain in the right lumbar region of several weeks duration. He did not have any symptoms related to the adrenal mass and was normotensive. Furthermore, hematological and biochemical investigations revealed normal complete blood count, serum electrolyte, cortisol levels, and urinary Vanillylmandelic acid levels [Table 1]. The initial USG scan suggested a large (24 × 18 × 17 cm) well-defined, homogeneous hyperechoic mass noted in the right lumbar region without any vascularity on color Doppler with a diagnosis of adrenal lipoma/adrenal myelolipoma.
Subsequently, contrast-enhanced computed tomography (CECT) of the abdomen revealed a large well-defined encapsulated fat-containing homogeneous mass lesion measuring 22 (CC) × 18.1 (AP) × 15 (TR) cm in size seen in hepatorenal space displacing the right lobe of the liver superiorly and the right kidney inferomedially [Figure 1]a. Intraoperatively, it revealed a huge, encapsulated, soft, lobulated mass which was enucleated. The mass was resected and sent for Histopathological examination. Gross examination [Figure 1]b of the specimen revealed a large, rounded, encapsulated yellowish fibrofatty tumor mass measuring 23 × 17.5 × 14.5 cm, with smooth external surface. Serial sections of the tumor revealed almost uniform looking yellowish, lobulated, soft to firm areas with a zone of reddish brown hemorrhagic area. Microscopy revealed mature adipose tissue amidst which are seen hematopoietic elements containing myeloid, erythroid, megakaryocytic, lymphocyte, and plasma cells in different stages of maturation with foci of necrosis and hemorrhage [Figure 2]. However, even after extensive grossing, no adrenal tissue was identified. But correlating with imegeological location, histopathogical impression was consistent with giant myelolipoma.
|Figure 1: (a) CECT abdomen showing the right adrenal homogeneous mass; (b) gross specimen showing rounded, encapsulated, yellowish fibrofatty tumor mass measuring 23 × 17.5 × 14.5 cm|
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|Figure 2: Photomicrograph showing megakaryocytes and other hematopoitic cells|
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| Discussion|| |
Adrenal myelolipoma constitutes a rare tumor in histopathological practice, composed of variable proportions of mature adipose tissue and active hematopoietic elements. Several theories are based on the etiology and natural history of adrenal myelolipoma. The most widely accepted theory is adrenocortical cell metaplasia in response to stimuli, such as necrosis, inflammation, infection, and stress. Another school of thought has speculated about a stressful lifestyle and an unbalanced diet as a factor that may be involved in the pathogenesis of these tumors, and a third theory suggests that myelolipomas are derived from embryonic primitive mesenchymal cells.
Although conditions associated with endocrine disorders such as Cushing's/Addison's disease, congenital adrenal hyperplasia and hyperaldosteronism, or tumors such as ganglioneuroma and Hodgkin's lymphoma is found in adrenal gland alone; it can also be seen in conjuction with Adrenal Myelolipoma.,
Adrenal myelolipomas of diameter >5 cm can easily be detected on USG. CT scan is the most sensitive test in diagnosis of adrenal myelolipoma. The lesions are typically seen as a heterogeneous encapsulated suprarenal mass of low density. Negative attenuation values interspersed by dense myeloid tissue. When a diagnosis of adrenal myelolipoma is considered, it should be differentiated from other fat-containing retroperitoneal tumors such as retroperitoneal lipoma, liposarcoma, extrarenal Adrenal myelolipoma, primary, or metastatic adrenal malignancy of teratoma. Adrenal myelolipomas are generally hormonally inactive although cases associated with overproduction of hormones such as Dehydroepiandrosterone sulphate have also been reported.
Grossly, myelolipomas are solitary circumscribed mass ranging in size from few centimeters to 27 cm. These tumors are spherical to ovoid, well-circumscribed, cut surface showing variegated appearance with areas of yellowish tissue alternating with irregular areas dark red brown friable tissue. Microscopically, tumors are composed of variable admixture of mature adipose tissue with islands and nests of hematopoietic elements. The cellularity of hematopoietic elements is variable with presence of granulopoietic, erythropoietic, and megakaryocytic elements. Rarely, foci of calcification are also seen. Management of myelolipoma should be case-based. Small and asymptomatic lesions <5 cm should be monitored over a period of 1–2 years with imaging controls. Large asymptomatic tumors >10 cm should be excised surgically to prevent life-threatening spontaneous retroperitoneal hemorrhage and cardiovascular shock.
| Conclusion|| |
Adrenal myelolipomas are rare, benign tumors and are clinically silent, which can be misdiagnosed as angiolipoma. But giant myelolipomas, which are symptomatic, are surgical emergencies and of significant concern. Various imaging modalities should be accompanied with histopathological examination for confirmation.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]