PET/CT incidental detection of bilateral adrenal myelolipomas in a patient with a huge maxillary sinus carcinoma

[Difficulty with differential diagnosis on adrenal lesions in congenital adrenal cortex dysfunction: a series of clinical cases]

Congenital adrenal hyperplasia (CAH) encompasses a group of autosomal recessive disorders characterized by defects in enzymes critical for steroidogenesis, with 21-hydroxylase deficiency due to mutations in the CYP21A2 gene being the most prevalent form.Since the introduction of replacement therapy and neonatal screening programs in the 1950s, there has been a significant increase in survival rates among newborns diagnosed with CAH. However, despite these advancements, mortality associated with this condition remains disproportionately high. Achieving optimal therapeutic compensation through medication remains a complex challenge, contributing to a range of long-term complications. These complications stem from both the underlying disease and its treatment, impacting key physiological functions, including metabolism, growth and development, cardiovascular health, and fertility. These multifaceted outcomes underscore the need for ongoing research and the refinement of therapeutic approaches to better manage this intricate condition. This article presents a series of four clinical cases of CAH characterized by the absence of sustained compensation for glucoand mineralocorticoid deficiencies. These cases were further complicated by the development of large adrenal masses and ectopic testicular adrenal rest tissue (TART), emphasizing the challenges in achieving long-term disease management.

Adrenal myelolipoma: a comprehensive review

INTRODUCTION

Adrenal myelolipoma is an invariably benign neoplasm of the adrenal gland that is the second most common primary adrenal incidentaloma following adrenocortical adenomas. It is composed of elements of adipose tissue and extramedullary hematopoiesis. Hypotheses on stem cells and hormonal factors have been formulated regarding its pathogenesis that is still obscure. Despite its benign behavior, adrenal myelolipoma is clinically relevant as it might cause significant difficulties in the differential diagnosis of adrenal tumors.

METHODS

We have reviewed 420 cases reported between 1957 and 2017 on adrenal myelolipoma retrieved from PubMed and Scopus databases and also 20 of our case series to provide a comprehensive analysis of their pathology, epidemiological and clinical features.

RESULTS AND CONCLUSIONS

The average age for its diagnosis was 51 years, and no gender difference was observed. The average size of tumors was 10.2 cm. Congenital adrenal hyperplasia was associated to 10% of all cases analyzed, while other adrenal hypersecretory disorders (cortisol, aldosterone) were found in 7.5% of cases. Computed tomography and magnetic resonance imaging can be reliably used for its differential diagnosis. If the diagnosis of an adrenal myelolipoma is unambiguous, and no associated symptoms or hormonal activity are established, surgical intervention is usually not necessary.

Appearance of Adrenal Myelolipomas on 2-deoxy-2-(18F) fluoro-D-glucose Positron Emission Tomography-Computed Tomography

With the widespread use of 2-deoxy-2-(¹⁸F) fluoro-D-glucose positron emission tomography-computed tomography (FDG PET/CT) in oncologic imaging, it has become increasingly important for physicians who interpret FDG PET/CT scans to confidently recognize the spectrum of incidentally encountered benign and malignant findings. The adrenal glands represent an interesting nexus of multiple rare and common benign intrinsic tumors as well as metastases from a variety of primary malignancies. Given the breadth of adrenal gland pathology, careful description of the FDG PET/CT appearance of these pathologies is of value to help reduce misinterpretation. In this manuscript, we retrospectively and systematically review the FDG PET/CT imaging characteristics of benign adrenal myelolipomas in a small consecutive patient series. The myelolipomas in this series demonstrated differing degrees of macroscopic fat visible on CT, with generally mild FDG uptake fusing to the nonfatty portions of the lesions. At imaging follow-up, all of the myelolipomas in this series remained unchanged in appearance, helping to confirm their benign nature. The typical appearance of a myelolipoma on FDG PET/CT is a fat-containing adrenal mass with low-level FDG uptake in the nonfatty aspects of the mass, and such a lesion requires no further imaging workup.

Review of primary extra-adrenal myelolipoma of the thorax

Extra-adrenal myelolipoma happens in adrenal glands, and the thoracic location is extremely unusual. This is the first study involving 36 of patients with thoracic myelolipoma of English literature by investigating the clinical data, pathologic findings, radiological manifestation, and treatment strategy of all patients. Imageologic diagnosis including computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography scans is useful to identify the feature of extra-adrenal myelolipoma. Pathologic analysis is an effective method to clarify the diagnosis. In view of the potential progressive enlargement of the lesion, most myelolipomas are removed by surgery, and this operation has frequently been accomplished by using video-assisted thoracic surgery.

Metabolic and anatomic characteristics of benign and malignant adrenal masses on positron emission tomography/computed tomography: a review of literature

PET/CT with (18)F-fluorodeoxyglucose (FDG) or using different radiocompounds has proven accuracy for detection of adrenal metastases in patients undergoing cancer staging. It can assist the diagnostic work-up in oncology patients by identifying distant metastases to the adrenal(s) and defining oligometastatic disease that may benefit from targeted intervention. In patients with incidentally discovered adrenal nodules, so-called adrenal "incidentaloma" FDG PET/CT is emerging as a useful test to distinguish benign from malignant etiology. Current published evidence suggests a role for FDG PET/CT in assessing the malignant potential of an adrenal lesion that has been 'indeterminately' categorized with unenhanced CT, adrenal protocol contrast-enhanced CT, or chemical-shift MRI. FDG PET/CT could be used to stratify patients with higher risk of malignancy for surgical intervention, while recommending surveillance for adrenal masses with low malignant potential. There are caveats for interpretation of the metabolic activity of an adrenal nodule on PET/CT that may lead to false-positive and false-negative interpretation. Adrenal lesions represent a wide spectrum of etiologies, and the typical appearances on PET/CT are still being described, therefore our goal was to summarize the current diagnostic strategies for evaluation of adrenal lesions and present metabolic and anatomic appearances of common and uncommon adrenal lesions. In spite of the emerging role of PET/CT to differentiate benign from malignant adrenal mass, especially in difficult cases, it should be emphasized that PET/CT is not needed for most patients and that many diagnostic problems can be resolved by CT and/or MR imaging.