Adrenal rest tumor of the liver: a case report with immunohistochemical investigation of steroidogenesis

Hepatic Adrenal Rest Tumors Mimicking Hepatocellular Carcinoma: A Case Report and Review of the Literature

Adrenal rest tumors are rare collections of aberrantly located adrenocortical tissue. They are most commonly found in the kidneys, and hepatic involvement is rare with few published case reports. When located in the liver, imaging findings are frequently indistinguishable from hepatocellular carcinoma (HCC), but when resected, histologic examination shows adrenocortical tissue. Here, we present a patient with a history of nonalcoholic steatohepatitis with advanced fibrosis who was identified as having HCC by cross-sectional imaging but was found to have a hepatic adrenal rest tumor (HART) after resection. HARTs can share imaging characteristics with HCC, and this alternative diagnosis should be considered, especially for hepatic segment VII lesions.

Overview of the 2022 WHO Classification of Adrenal Cortical Tumors

The new WHO classification of adrenal cortical proliferations reflects translational advances in the fields of endocrine pathology, oncology and molecular biology. By adopting a question-answer framework, this review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the adrenal cortex pathologies that are now reflected in the 2022 WHO classification. The pathological correlates of adrenal cortical proliferations include diffuse adrenal cortical hyperplasia, adrenal cortical nodular disease, adrenal cortical adenomas and adrenal cortical carcinomas. Understanding germline susceptibility and the clonal-neoplastic nature of individual adrenal cortical nodules in primary bilateral macronodular adrenal cortical disease, and recognition of the clonal-neoplastic nature of incidentally discovered non-functional subcentimeter benign adrenal cortical nodules has led to redefining the spectrum of adrenal cortical nodular disease. As a consequence, the most significant nomenclature change in the field of adrenal cortical pathology involves the refined classification of adrenal cortical nodular disease which now includes (a) sporadic nodular adrenocortical disease, (b) bilateral micronodular adrenal cortical disease, and (c) bilateral macronodular adrenal cortical disease (formerly known primary bilateral macronodular adrenal cortical hyperplasia). This group of clinicopathological entities are reflected in functional adrenal cortical pathologies. Aldosterone producing cortical lesions can be unifocal or multifocal, and may be bilateral with no imaging-detected nodule(s). Furthermore, not all grossly or radiologically identified adrenal cortical lesions may be the source of aldosterone excess. For this reason, the new WHO classification endorses the nomenclature of the HISTALDO classification which uses CYP11B2 immunohistochemistry to identify functional sites of aldosterone production to help predict the risk of bilateral disease in primary aldosteronism. Adrenal cortical carcinomas are subtyped based on their morphological features to include conventional, oncocytic, myxoid, and sarcomatoid subtypes. Although the classic histopathologic criteria for diagnosing adrenal cortical carcinomas have not changed, the 2022 WHO classification underscores the diagnostic and prognostic impact of angioinvasion (vascular invasion) in these tumors. Microscopic angioinvasion is defined as tumor cells invading through a vessel wall and forming a thrombus/fibrin-tumor complex or intravascular tumor cells admixed with platelet thrombus/fibrin. In addition to well-established Weiss and modified Weiss scoring systems, the new WHO classification also expands on the use of other multiparameter diagnostic algorithms (reticulin algorithm, Lin-Weiss-Bisceglia system, and Helsinki scoring system) to assist the workup of adrenal cortical neoplasms in adults. Accordingly, conventional carcinomas can be assessed using all multiparameter diagnostic schemes, whereas oncocytic neoplasms can be assessed using the Lin-Weiss-Bisceglia system, reticulin algorithm and Helsinki scoring system. Pediatric adrenal cortical neoplasms are assessed using the Wieneke system. Most adult adrenal cortical carcinomas show > 5 mitoses per 10 mm² and > 5% Ki67. The 2022 WHO classification places an emphasis on an accurate assessment of tumor proliferation rate using both the mitotic count (mitoses per 10 mm²) and Ki67 labeling index which play an essential role in the dynamic risk stratification of affected patients. Low grade carcinomas have mitotic rate of ≤ 20 mitoses per 10 mm², whereas high-grade carcinomas show > 20 mitoses per 10 mm². Ki67-based tumor grading has not been endorsed in the new WHO classification, since the proliferation indices are continuous variables rather than being static thresholds in tumor biology. This new WHO classification emphasizes the role of diagnostic and predictive biomarkers in the workup of adrenal cortical neoplasms. Confirmation of the adrenal cortical origin of a tumor remains a critical requirement when dealing with non-functional lesions in the adrenal gland which may be mistaken for a primary adrenal cortical neoplasm. While SF1 is the most reliable biomarker in the confirmation of adrenal cortical origin, paranuclear IGF2 expression is a useful biomarker in the distinction of malignancy in adrenal cortical neoplasms. In addition to adrenal myelolipoma, the new classification of adrenal cortical tumors has introduced new sections including adrenal ectopia, based on the potential role of such ectopic tissue as a possible source of neoplastic proliferations as well as a potential mimicker of metastatic disease. Adrenal cysts are also discussed in the new classification as they may simulate primary cystic adrenal neoplasms or even adrenal cortical carcinomas in the setting of an adrenal pseudocyst.

Extra-adrenal, non-functional adrenocortical carcinoma presenting with acute abdomen: a case report

BACKGROUND

Adrenocortical carcinoma is a rare malignancy, with 43% being non-functional. These may arise from adrenal rest anywhere in the embryonic pathway of the adrenal glands. In the context of extra-adrenal and retroperitoneal tumors, the exact pathologic diagnosis is challenging. The case reported here, to the best of our knowledge, is the seventh reported case of extra-adrenal non-functional adrenocortical carcinoma.

CASE PRESENTATION

We report a case of extra-adrenal non-functional adrenocortical carcinoma in a 15-year-old Persian boy who presented with an acute abdomen. He underwent surgical resection. Pathologic findings based on immunohistochemistry and cellular morphology confirmed adrenocortical carcinoma. He was treated with mitotane for 24 months. During a follow-up period of 30 months, no recurrence or metastases were found.

CONCLUSION

Despite the rarity of extra-adrenal adrenocortical carcinoma, presentation with an acute abdomen may occur, and the tumor may be found anywhere in the adrenal embryonic pathway. On the other hand, tumor behavior and prognosis in children may be different from what we expect in adults.

Lipid droplets: platforms with multiple functions in cancer hallmarks

Lipid droplets (also known as lipid bodies) are lipid-rich, cytoplasmic organelles that play important roles in cell signaling, lipid metabolism, membrane trafficking, and the production of inflammatory mediators. Lipid droplet biogenesis is a regulated process, and accumulation of these organelles within leukocytes, epithelial cells, hepatocytes, and other nonadipocyte cells is a frequently observed phenotype in several physiologic or pathogenic situations and is thoroughly described during inflammatory conditions. Moreover, in recent years, several studies have described an increase in intracellular lipid accumulation in different neoplastic processes, although it is not clear whether lipid droplet accumulation is directly involved in the establishment of these different types of malignancies. This review discusses current evidence related to the biogenesis, composition and functions of lipid droplets related to the hallmarks of cancer: inflammation, cell metabolism, increased proliferation, escape from cell death, and hypoxia. Moreover, the potential of lipid droplets as markers of disease and targets for novel anti-inflammatory and antineoplastic therapies will be discussed.

Adrenal Rest Tumor of the Liver Preoperatively Diagnosed as Hepatocellular Carcinoma

Background

Hepatic adrenal rest tumors are rare and show similar findings to hepatocellular carcinoma (HCC). It is difficult to distinguish an adrenal rest tumor from HCC due to radiological similarity. We report a case of an adrenal rest tumor in the liver that mimicked HCC radiologically.

Case Presentation

A 67-year-old female was referred to our hospital due to the finding of a hepatic mass. Enhanced computed tomography revealed a 17 mm well-defined tumor that was enhanced in the arterial phase and washed out in the portal and delayed phase in the posterosuperior subsegment of the right hepatic lobe, and HCC was suspected. We performed a subsegmental resection of the liver. Microscopic findings showed that the tumor was composed of pale cells, and tumor cells were aligned in alveolar or fascicular arrangements in a similar manner to features of adrenocortical tissue. Immunohistochemically, the tumor expressed synaptophysin and CD56. The final histopathologic diagnosis in this case was an adrenal rest tumor of the liver.

Conclusions

An adrenal rest tumor is similar to HCC in radiological findings. This hepatic tumor should be added to the list of radiological differential diagnoses of hypervascular hepatic tumors.

Adrenal ectopy of adult groin region: a systematic review of an unexpected anatomopathologic diagnosis

PURPOSE

Adrenal ectopy is a rare condition, caused by abnormal embryological development of the adrenal glands and testis. This anomaly is asymptomatic and is generally diagnosed in childhood. Most cases of adrenal ectopy of the groin region have been found incidentally during surgery. This review aims to evaluate the incidence of adrenal ectopy of the adult groin region, as well as its short- and long-term significance.

METHODS

A systematic literature search was performed using the EMBASE, MEDLINE, PubMed and Cochrane Central databases to identify all studies published until December 2015. Articles written in English containing the keywords: ''ectopic adrenal tissue'' or ''aberrant adrenal tissue'' or ''adrenal heterotopy'' combined with ''groin region'' or ''inguinal'' or ''testicular" or "scrotum" and "adult" were selected.

RESULTS

Fifteen articles matched the review criteria. A total of 21 cases (100 % male) were included. No cases of bilateral nodules have been reported. The mean age at diagnosis was 43.5 years old (range 19-78 years). A predominance of right-sided lesions was observed (71.4 %). The mean size reached 7.6 mm (range 2-40 mm) and hernia sacs were the most common location (47.6 %). All histological analyses of harvested tissues consisted of adrenal cortex without medulla.

CONCLUSIONS

Our results suggest that routine pathological examination of any groin tissue excised during inguinal hernia repairs is required for the diagnosis of adrenal ectopy in the groin. Although there is no current evidence that endocrine or oncologic complications can occur from excision of ectopic adrenal tissue, further confirmatory studies may be required.

Hepatic adrenal rest tumor: Diagnostic pitfall and proposed algorithms to prevent misdiagnosis as lipid-rich hepatocellular carcinoma

We present a case of adrenal rest tumor of the liver in which differential diagnosis from lipid rich-hepatocellular carcinoma (HCC) was challenging. The patient was a 50-year-old woman in whom a 3-cm tumorous mass was discovered in segment 7 of the liver during computed tomography evaluation of a uterine leiomyoma. The preoperative diagnosis was HCC, and subsegmental liver resection was performed. The tumor appeared as a well-demarcated golden yellow nodule consisting of clear or partially eosinophilic cells arranged in a trabecular pattern. The initial impression of this lesion was that of clear cell type or lipid-rich type HCC because it stained positive for Hep Par1, but negative for arginase-1 and positive for CD56 which is one of the neuroendocrine markers. The lesion also stained positive for SF-1 and 3β-HSD, both of which are markers of adrenocortical tissue. The final diagnosis was hepatic adrenal rest tumor. Hepatic adrenal rest tumor should be considered in the differential diagnosis of segment 7 tumor. A diagnostic algorithm that includes immunohistochemical staining for CD56 and arginase-1 is to rule out the possibility of lipid-rich HCC.

Growth patterns of placental and paraovarian adrenocortical heterotopias are different

Two cases of adrenocortical heterotopia are reported. One is in a full-term placenta. The other is adjacent to the ovarian hilum of an adult. Both are incidental findings. Despite sharing similar histological and immunological features, they show different growth patterns. The literature is reviewed and adrenocortical heterotopias of different locations are compared. New hypotheses of its histogenesis are discussed.

Malignant adrenal rest tumor of the retroperitoneum producing adrenocortical steroids

We present a case of a malignant adrenal rest tumor arising from the retroperitoneum with Cushing's syndrome in a 31-year-old female. Her serum cortisol and dehydroepiandrosterone sulfate levels were elevated, while adrenocorticotropic hormone levels were low. Computed tomography scans and magnetic resonance imaging revealed a retroperitoneal tumor with no visible lesions in the adrenal glands and ovaries. From those results and the histopathologic findings following biopsy of an enlarged supraclavicular lymph node, the patient was diagnosed as a malignant adrenal rest tumor of the retroperitoneum. Despite chemotherapy, the patient died of rapid development of multiple metastases. Autopsy revealed a large tumor that extended around the abdominal aorta from the levels of the left kidney to the aortic bifurcation with generalized metastases. Tumor cells were characterized by clear and eosinophilic cytoplasm and atypical nuclei that exhibited frequent and atypical mitoses. Immunohistochemistry regarding steroidogenesis was performed and revealed that the tumor cells were immunopositive for adrenal 4 binding protein/steroidogenic factor-1, cholesterol side-chain cleavage enzyme, 17α-hydroxylase, and 21-hydroxylase. We thus elucidated the adrenocortical steroid production in the tumor cells causing Cushing's syndrome. This case report first demonstrates the steroidogenic capacity in a malignant adrenal rest tumor.

A case of adrenal rest tumor of the liver: Radiological imaging and immunohistochemical study of steroidogenic enzymes

A case of adrenal rest tumor in the liver of a 67-year-old female was reported. The tumor appeared on diagnostic imaging as a hypervascular and fat-containing mass at the periphery of right hepatic lobe and required differential diagnosis from hepatocellular carcinoma (HCC). Pathological diagnosis of the intraoperative frozen section taken under laparoscopic liver biopsy could not exclude fat-containing HCC. Therefore, she underwent partial resection of the right hepatic lobe. A yellowish-brown mass, 17 x 14 x 11 mm in a diameter, was located in the subcapsular portion. Histologically, the mass presented features similar to those of the adrenal cortex and was composed of pale cells. Immunohistochemically, the mass expressed the adrenal 4-binding protein and several enzymes involved in the synthesis of adrenocortical steroids. Based on these findings, the hepatic mass was finally diagnosed as an adrenal rest tumor of the liver.

Nonfunctioning adrenal rest tumor of the liver: radiologic appearance

We describe the radiologic features of an adrenal rest tumor of the liver. The adrenal rest tumor appeared on ultrasound as a round, well defined, heterogeneous, solid mass in the posterior aspect of the liver, on angiography as a homogeneous hypervascular mass, and on dynamic CT as a mass containing components of both fat density and soft tissue density and showing early fill-in and early fill-out. Adrenal rest tumors should be included in the lists of hypervascular or fat-containing masses in the liver.