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RCR RADIOLOGY CASE REPORTS
Case Report
Unusual appearance of an adrenal ganglioneuroma
Mohit Bansal, MDª,*, Adib R. Karam, MDª, Sonja D. Chen, MDb, Mehran N. Kohnehshahri, MDb, Travis M. Cotton, MDC, Maria L. Garcia Moliner, MDb
a Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy St., Providence, RI 02903 USA
b Department of Surgical Pathology, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, USA
“Department of Surgery, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, USA
ARTICLE INFO
Article history: Received 8 September 2020 Revised 27 November 2020 Accepted 28 November 2020
Keywords: Adrenal tumor Ganglioneuroma Adrenocortical carcinoma Adrenal myelolipoma
ABSTRACT
Ganglioneuromas are rare tumors that occur spontaneously or arise from a poorly differ- entiated neuroblastic tumor. Although they are typically described in the pediatric pop- ulation, they can occur in adults. Ganglioneuromas are often discovered incidentally and their typical imaging appearance, although non-specific, is that of a well-defined solid mass. We are presenting a case of a fat-containing adrenal lesion in a 53-year-old male. The ex- tensive lipomatous changes within the lesion led to the presumption that it represented an adrenal myelolipoma. Pathology revealed a ganglioneuroma with extensive lipomatous changes. This is an uncommon presentation of an adrenal ganglioneuroma mimicking an adrenal myelolipoma. The diagnosis of an adrenal ganglioneuroma raises the possibility of syndromic associations for which patients may undergo genetic testing. We provide a re- view of typical imaging features of an adrenal ganglioneuroma and provide insight into the situations in which a ganglioneuroma can be suggested as a diagnostic consideration.
@ 2020 The Authors. Published by Elsevier Inc. on behalf of University of Washington. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Case report
Ganglioneuromas (GN) are rare tumors that may occur sponta- neously or arise from a poorly differentiated neuroblastic tu- mor. Adrenal GNs are often discovered incidentally and their typical imaging appearance, although nonspecific, is that of a well-defined solid mass.
A 53-year-old male with no significant past medical his- tory presented to the emergency department with left lower quadrant pain. The patient reported having fevers and chills and was tachycardie at the time of presentation. No sig- nificant laboratory abnormalities were identified. A com- puted tomography (CT) scan of the abdomen and pelvis with intravenous contrast revealed acute sigmoid diverticulitis and the patient was subsequently treated with conservative
* Corresponding author. E-mail address: mohit.bansal@lifespan.org (M. Bansal).
https://doi.org/10.1016/j.radcr.2020.11.046
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40 ± 24 HU A : 1.15 cm ”
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medical management. Incidentally, a 5.4 cm right adrenal le- sion containing macroscopic fat and peripheral calcifications (Fig. 1) was found. The lesion also had a lobulated contour and perilesional fat stranding. A nonurgent surgical consultation was recommended given the size of the lesion and the pres- ence of atypical imaging features. Adrenal myelolipoma was raised as a potential diagnosis due to the presence of macro- scopic fat.
Given the size and the atypical appearance of the adrenal mass, the patient elected to proceed with a laparoscopic right adrenalectomy. Surgery was performed 6 months after the ini- tial discovery of the adrenal lesion. Operative notes remark that the lesion was “rather adherent to surrounding tissue and somewhat inflamed but did not appear malignant.” The oper- ation was uneventful, and the patient had a benign postoper- ative course.
Surgical pathology revealed that the excised lesion was consistent with a GN with extensive lipomatous changes. The resected adrenal gland (85 g) had a well-circumscribed nodule (5.1 × 3.9 × 3 cm) within the adrenal medulla with a tan yel- low, soft, and fatty cut surface (Fig. 2a). Microscopically, the tu- mor was composed of a mixture of Schwann cells and mature ganglion cells, diagnostic features of a GN (Fig. 2c). In addition, there was extensive admixed mature adipose tissue (Fig. 2b). The possibility of an adrenal collision tumor was eliminated as no other distinct histology was present.
Given the association of GNs with hereditary adrenal tu- mor syndromes such as Multiple Endocrine Neoplasia type 2, succinate dehydrogenase complex iron sulfur subunit vari- ants, and Neurofibromatosis type I the patient was referred to the Genetics Clinic and has met with a genetics counselor. At this time, the patient is considering whether to proceed with genetic testing and the possibility of a syndromic association remains unknown. The patient is otherwise feeling well and is currently asymptomatic.
Discussion
GN is a rare tumor composed entirely of ganglion cells and Schwannian stroma [1]. A GN may occur spontaneously or may be formed by the spontaneous maturation of a neuroblas- toma. A neuroblastoma begins as a morphologically undiffer- entiated or a poorly differentiated neuroblastic tumor [2]. The relative frequency of spontaneously occurring GN and those arising from a neuroblastoma is unknown. The median age at diagnosis is approximately 7 years, although it may occur in all age groups [1,3]. The most common locations are the pos- terior mediastinum (41.5%), retroperitoneum (37.5%), adrenal gland (21%), and neck (8%) [1,4]. Rarely, GNs are found in the spermatic cord, heart, or gastrointestinal tract [4].
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A study of 49 patients with a primary GN found that a GN may present with metabolic activity such as increased secretion of catecholamines and/or metaiodobenzylguani- dine uptake [5]. Rarely, GN secretes sufficient quantities of vanillylmandelic acid or homovanillic acid to manifest with symptoms of catecholamine excess, such as flushing [6]. The tumor is most commonly identified incidentally and patients are typically asymptomatic at the time of discovery [3]. However, a GN may result in coughing, abdominal pain, or dyspnea secondary to mass effect [1].
Differentiating a GN from other nonhyperfunctioning adrenal tumors such as adenoma, adrenocortical carcinoma, myelolipoma, or hemangioma may be challenging [3]. A study performed to characterize the appearance of an adrenal GN on CT imaging found that their “typical imaging character- istics” include solid attenuation and postcontrast enhance- ment, which are nonspecific. Calcifications may be present in a GN while vascular invasion was found to be an uncharac- teristic feature [3]. No single defining characteristic has been found to differentiate a GN from an adrenocortical carcinoma. Extensive adipose tissue in GNs is uncommon; moreover, its location in the adrenal gland is unusual as GNs have been re- ported to more frequently arise in the posterior mediastinum and retroperitoneum [7-10]. A primary diagnostic considera- tion for an adrenal lesion containing macroscopic fat is an adrenal myelolipoma. Differentiating a GN from an adrenal myelolipoma may be possible based on the presence of macro- scopic fat, but discerning the two entities may be challenging in the context of a lipomatous GN.
Our patient presented with an indeterminate right adrenal mass with adrenal myelolipoma as a diagnostic possibility due to the significant amount of macroscopic fat. However, the mass measured over 4 cm (Fig. 1). According to the American College of Radiology (ACR) guidelines, an adrenal mass between the size of 1 and 4 cm with no diagnostic benign imaging features (macroscopic fat, cyst, hemorrhage, nonenhancement, calcifications, or density <10 Hounsfield units) which demonstrates stability for 1 year or longer is most likely benign with no additional work-up required. If
an adrenal mass is greater than 4 cm in size without benign diagnostic features and the patient does not have a history of cancer, surgical resection (without biopsy) is recommended to treat a possible primary adrenocortical carcinoma [11].
In summary, GNs are usually asymptomatic masses com- monly found within the posterior mediastinum and retroperi- toneum, and less commonly arise from the adrenal medulla [12]. The presence of fat is unusual and lipomatous GN is an extremely rare variant first reported in 1999 by Hara et al [8]. Patients diagnosed with a GN carry a good prognosis after sur- gical resection [12]. We presented a case of a rare adrenal tu- mor with atypical imaging features which was proven to rep- resent an adrenal GN with an extensive mature adipocytic component following surgical resection.
Patient consent
Patient have no objection to any of the above and give permis- sion for the same.
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