2-Deoxy-2-[18F]Fluoro-D-Glucose Positron Emission Tomography Uptake in a Giant Adrenal Myelolipoma

doi:10.1016/S1536-1632(02)00018-5

Molecular Imaging & Biology

Volume 4, Issue 5, September–October 2002, Pages 355-358

https://doi.org/10.1016/S1536-1632(02)00018-5 Get rights and content

Abstract

Incidental adrenal lesions found on anatomic imaging are not uncommon. 2-Deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography (FDG-PET) imaging is highly accurate in the differentiation of benign from malignant adrenal lesions, both in patients with proven malignancy and with adrenal lesions detected incidentally. A 60-year-old white female with a history of lower mid-back pain underwent computerized tomography (CT) imaging that identified a 15-cm complex mass within the left adrenal gland with soft tissue, cystic, and adipose components. FDG-PET imaging showed significant hypermetabolic activity within portions of the mass with central photopenia suggesting a malignant lesion with central necrosis. Surgical excision and pathological examination, however, revealed a benign adrenal myelolipoma with extensive adenomatous and hematopoietic elements. Prior reports of adrenal myelolipoma evaluated with FDG-PET imaging have described no significant FDG uptake within these benign tumors. This case is an unusual example of histologically proven benign adrenal myelolipoma that was hypermetabolic on FDG-PET imaging. Correlation of pathologic and imaging findings demonstrated that the hypodense regions on CT were hypometabolic on FDG-PET and corresponded to cystic necrosis and adipose elements, whereas the adenomatous and hematopoietic elements were hypermetabolic.(Mol Imag Biol 2002;4:355–358)

Introduction

nexpected adrenal lesions are often found on computerized tomography (CT) or magnetic resonance imaging (MRI) imaging performed for suspected abdominal disease. Most adrenal lesions are likely to be benign, even in patients with known primary extra-adrenal malignancy.¹ Benign adenomas are the most common cause of nonfunctioning adrenal lesions. The incidence of adrenal myelolipoma at autopsy varies from 0.08–0.2%.² Histologically, they are benign neoplasms composed of mature adipose tissue and hematopoietic elements.3, 4, 5 These benign adrenal lesions usually remain small and asymptomatic; however, they occasionally reach massive proportions and become symptomatic, resulting in non-specific complaints generally related to mechanical compression of adjacent organs.

Section snippets

Case Report

A 60-year-old white female presented with a history of non-specific lower mid-back pain with no prior history of malignancy. An MRI of the lumbar spine showed a large mass in the left retroperitoneum, confirmed by a CT of the abdomen. On CT, this 15-cm heterogeneous mass (Figure 1) contained cystic, solid, and adipose components that appeared to be arising within or adjacent to the left adrenal gland. Calcification was also present within the lesion. The patient had no symptoms of hormone

Discussion

In this case, a 15-cm adrenal myelolipoma demonstrated areas of marked FDG uptake in a pattern suggestive of a metabolically active malignant neoplasm. To our knowledge, the few reported cases of adrenal myelolipoma that have been imaged with FDG-PET have shown no significant FDG uptake.⁶

Adrenal myelolipoma is a benign neoplastic lesion composed of mature adipose tissue admixed with hematopoietic elements in various proportions. The age range of patients with adrenal myelolipoma is 17 to 93

Conclusion

This case is an unusual example of histologically proven benign adrenal myelolipoma with extensive adenomatous changes and hematopoietic elements that were hypermetabolic on FDG-PET imaging.

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Bilateral giant adrenal myelolipomas presenting as an enlarging ventral hernia: Radiologic-pathologic correlation and literature review
2015, Radiology Case Reports
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In early reported cases of adrenal myelolipoma imaged with FDG-PET, usually no significant metabolic uptake was shown (12, 13). However, more recently, Ludwig et al (12) reported mixed metabolic activity in a myelolipoma, suggesting that the lack of activity corresponds to “necrotic and adipose” elements in the tumor, and that the presence of activity (that is, if the tumor is FDG-PET avid) corresponds to the “adenomatous and hematopoietic” elements. When imaging results are equivocal, especially when the tumor is large and/or heterogeneous and interspersed with fat and denser nonfatty myeloid tissue on CT, then image-guided, fine-needle aspiration may be warranted.
Adrenal myelolipomas are fat-containing tumors that are rare, usually small, and unilateral, as well as asymptomatic. They can, however, occur bilaterally and enlarge significantly, resulting in clinical symptoms. A middle-aged male presented with an enlarging ventral hernia that was attributed to giant bilateral adrenal myelolipomas. With a combined measurement of at least 20 × 15 cm, to our knowledge, the size of the masses is one of the largest reported for this particular entity.
Positron emission tomography-avid adrenal mass and incidental renal mass in a 70-year-old woman with newly diagnosed breast cancer
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Left adrenalectomy led to the diagnosis of a benign adrenal adenoma. There have also been case reports of PET-avid adrenal masses being ultimately diagnosed as adrenal myelolipomas.9,10 The evaluation of an adrenal mass requires a thoughtful approach incorporating laboratory and radiologic modalities.
Bilateral adrenal myelolipomas in a woman with chronic anticoagulation, postmenopausal uterine bleeding, primary hyperparathyroidism and hyperthyroidism
2013, American Journal of the Medical Sciences
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In cases involving suspected bilateral adrenal myelolipomas, adrenalectomy of the larger lesion whether it is symptomatic or asymptomatic has been shown to be successful in the literature, with the largest adrenal myelolipoma reported measuring 31 cm.4 Although myelolipomas have characteristics that make the diagnosis confident via CT or magnetic resonance imaging (MRI), we believe biopsy is warranted to confirm the diagnosis and rule out other adrenal tumors with heterogeneous appearance on conventional imaging. Such an adrenal biopsy can be performed as an open procedure or CT scan-guided adrenal puncture to rule out malignancy of such on imaging heterogeneous appearing adrenal lesions with areas of low density tissue measuring between − 30 and − 90 Hounsfield units, suggestive of fatty tissue.26,27 Before any adrenal biopsy, however, one must rule out pheochromocytoma by measuring plasma-free metanephrines and/or 24-hour urinary fractionated metanephrines.28
Adrenal myelolipomas are rare, usually benign unilateral tumors. Their management has controversially been discussed. The authors here present a 53-year-old African American female Jehovah’s witness with postmenopausal uterine bleeding on chronic anticoagulation and episodic right flank pain who was found to have bilateral myelolipomas in addition to primary hyperparathyroidism. In collaboration with gynecology, midline laparotomy was performed to remove uterus and both ovaries in addition to the right adrenal gland for a 62 × 79 mm myelolipoma. An open biopsy of the left adrenal mass measuring 42 × 43 mm revealed myelolipoma and ruled out malignancy. Pathology confirmed bilateral myelolipomas, endometrial polyps, and leiomyomata uteri. After an uneventful recovery, the patient then underwent a right inferior parathyroidectomy for parathyroid adenoma. This case illustrates the challenges in deciding when to surgically intervene for bilateral adrenal myelolipoma and, for the first time, associates various other endocrinopathies, although no known endocrine neoplasia syndrome variant was present.
Myelolipomas and other fatty tumours of the adrenals
2011, Arab Journal of Urology
Lipomatous tumours of the adrenals are almost always benign. The importance of recognising their characteristic radiological features, leading to their correct treatment, is fundamental, as there has been an increase in the identification of these lesions. Our goal was to review all lipomatous tumours of the adrenal glands, particularly myelolipomas, their imaging methods and surgical management, updated in 2011.
This was a retrospective review of articles published in the USA and Europe, from 1979 to date. The sites from which information was retrieved covered PubMed, Medscape, Clinical Imaging, Histopathology, Urologia Internationalis, Archives of Surgery, JACS, the American Urological Association, BMJ, Medline, and Springer Link. We report areas of controversies in addition to well established guidelines.
We reviewed 45 articles, that confirmed, with a high level of evidence-based medicine, that the diagnosis of a lipomatous adrenal tumour is made by various imaging procedures, particularly computed tomography (CT). We emphasise the importance to their management of the initial size of the adrenal mass, its increase in size over time, in addition to the presence of symptoms.
Lipomatous tumours of the adrenals are most frequently benign. The diagnosis is usually made by various techniques, in particular CT. The fundamental characteristics indicating the necessity of surgical intervention are the symptoms presented, volume of the tumoral mass (>5 cm), and the increase in size of the tumour as shown in two consecutive imaging studies.
Adrenocortical incidentaloma with uncertain prognosis associated with an inadequately treated congenital adrenal hyperplasia
2010, Annales d'Endocrinologie
Citation Excerpt :
Histological findings were in favor of a tumor with an uncertain prognosis according to Weiss's criteria. Some reports have described an uptake of the tracer in benign tumors, e.g. cortisolic adenoma, myelolipoma and adrenal hyperplasia in a patient with 21OHD [17–20], but uptake was low in most of cases. The uptake we observed in our case remains to be explained. (
Les observations de volumineuses tumeurs surrénaliennes dans les blocs enzymatiques surrénaliens sont rares, et très exceptionnellement malignes, en dehors du déficit en 11β-hydroxylase. Nous rapportons le cas d’un patient porteur d’un bloc en 21-hydroxylase (hétérozygote composite pour deux mutations sévères du gène CYP21A2) en rupture ancienne de traitement dont la réévaluation, à l’âge de 36 ans, a permis de mettre en évidence une masse de quatre centimètres de diamètre au niveau de la surrénale gauche dont les caractéristiques étaient hautement suspectes de malignité (scanner et tomographie à émission de positons [TEP] au 18FDG), ayant imposé une vérification histologique en faveur d’une lésion de pronostic incertain (score de Weiss à 3). Malgré l’absence habituelle de transformation maligne, notre observation rappelle la nécessité de la poursuite d’un traitement freinateur à l’âge adulte avec surveillance scannographique régulière à la recherche de l’apparition d’une tumeur surrénalienne isolée (avec prise en charge chirurgicale au moindre signe suspect de malignité).
Large adrenal tumors are rarely associated with adrenal enzymatic deficiency, except in 11-ß-hydroxylase insufficiency. These tumors are exceptionally malignant. We report here the case of a patient with a congenital 21-hydroxylase deficiency (compound heterozygote for two severe mutations in the CYP21A2 gene) untreated for 20 years. His evaluation at 36 years of age showed a four-centimeter mass in the left adrenal gland, with most characteristics suggestive of malignancy (CT and positron emission tomography [PET] scan). We performed a surgical resection that established the diagnosis of adrenocortical tumor of uncertain prognosis (Weiss's score: 3). Even though malignant tumors are unusual in adrenal deficiency, our observation shows the need for a replacement therapy during adulthood, with a regular CT scan follow up in order to diagnose early isolated adrenal adenoma and remove it in case of malignancy suspicion.
Examination and management of adrenal incidentalomas. Expert consensus of the French Society of Endocrinology
2008, Annales d'Endocrinologie
À la demande de la Société française d’endocrinologie un panel d’expert endocrinologues, radiologues, médecins nucléaires, chirurgiens s’est constitué pour élaborer des recommandations quant à l’exploration et la prise en charge des incidentalomes surrénaliens. La méthodologie a reposé sur l’analyse systématique et critique de la littérature sur les thèmes de l’épidémiologie, l’histoire naturelle, l’exploration radiologique, l’exploration scintigraphique, l’exploration hormonale, les indications de la chirurgie et les modalités de surveillance des incidentalomes surrénaliens. Ce texte correspond aux recommandations du groupe d’expert validé par la Société française d’endocrinologie. Après avoir insisté sur le peu de données disponibles dans la littérature et qui ne permettent pas des recommandations « basées sur les preuves » les points fondamentaux de ces recommandations sont : l’importance de l’analyse TDM des lésions pour poser l’indication opératoire, la nécessité de recherche biologique systématique du phéochromocytome, la réalisation systématique d’un test de freinage minute à la dexaméthasone pour dépister les hypercorticismes latents, la difficulté d’interprétation des anomalies subtiles du bilan biologique corticotrope, les indications larges de la chirurgie pour les tumeurs de plus de 4 cm de grand axe, l’intérêt de l’appréciation clinique des cibles tissulaires du cortisol et de leur évolutivité dans la surveillance des adénomes corticaux non opérés.

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Brief articles2-Deoxy-2-[18F]Fluoro-D-Glucose Positron Emission Tomography Uptake in a Giant Adrenal Myelolipoma

Abstract

Introduction

Section snippets

Case Report

Discussion

Conclusion

Metastases in carcinomaanalysis of 1000 autopsied cases

Cancer

Benign lipomatous tumors

Giant adrenal myelolipomacase report and review of the literature

Pathol. Int.

Adrenal gland myelolipomaradiological review

Arch. Esp. Urol.

Giant adrenal myelolipoma

South Med. J.

Brief articles
2-Deoxy-2-[¹⁸F]Fluoro-D-Glucose Positron Emission Tomography Uptake in a Giant Adrenal Myelolipoma