Mesothelial cyst of the adrenal gland

True mesothelial cyst of the adrenal gland: its clinical profile and management

The incidence of adrenal cysts is 0.06% and only 9% of these are true mesothelial cysts. Here, we present a case of a true mesothelial cyst together with a review of the literature. A female in her 30s presented to the surgical outpatient department complaining of right flank pain. Her contrast-enhanced CT scan revealed a 7.5×6.5×4.5 cm right adrenal gland cyst. The patient underwent a laparoscopic right adrenalectomy. Immunohistopathology revealed the cyst to be mesothelial in nature. The majority of true mesothelial adrenal cysts are benign, unilateral and more common in women. Any adrenal cyst diagnosed as a functional lesion or one that may be malignant or with a diameter of 5 cm or greater requires surgical care whereas smaller lesions can be managed conservatively. Laparoscopic adrenalectomy for an adrenal cyst of diameter greater than 6 cm is a safe and feasible procedure in expert hands if there is no invasion of surrounding tissue.

A Cyst-ematic Analysis of the Adrenal Gland: A Compilation of Primary Cystic Lesions From Our Institution and Review of the Literature

OBJECTIVES

Although primary adrenal lesions and metastases are most commonly encountered, de novo cysts of the adrenal gland can occasionally occur.

METHODS

We analyzed the pathology archives at the Hospital of the University of Pennsylvania for diagnoses of cystic lesions of the adrenal gland between 1998 and 2020. Patient demographics and clinical information were extracted, and pathology slides and stains, as appropriate, were analyzed. The literature between 1998 and 2020 was also searched for large case series involving cystic adrenal lesions.

RESULTS

We found 18 cystic lesions of the adrenal gland in our archives, categorized as pseudocysts (7), endothelial cysts (5), mesothelial cysts (2), mature teratoma (1), cystic adrenal cortical adenoma (1), cystic pheochromocytoma (1), and cystic metastasis (1). The mean age at time of diagnosis was 52.3 years, and the mean size of the cysts was 6.0 cm. There was a slight female predilection, and cysts were more likely to be found on the left side. All lesions were incidental findings. The cystic metastasis was clear cell renal cell carcinoma. Our findings were also compared with those found in the literature published within the same timeframe.

CONCLUSIONS

Adrenal cysts are rare entities. Our findings are concordant with other large studies and provide additional cases to the existing literature. In addition, our literature search expands the possible differential diagnoses for cystic lesions arising in the adrenal gland.

Clinicopathological and immunohistochemical analysis of epithelial-lined (true) cysts of the adrenal gland with proposal of a new histogenetic categorization

Epithelial- lined (true) cysts are rare lesions and until now the only information we had about their histogenesis was based on the analysis of a few cases. We retrospectively reviewed 8 cases of cysts with a true epithelial lining (confirmed immunohistochemically). The pathological findings and immunohistochemical analysis of the epithelial linings allowed for categorization of the cysts into 3 groups. Five cysts had pure mesothelial lining, which was flattened to cuboidal, and demonstrated a positive reaction for mesothelial markers (eg. calretinin, WT1), and a negative reaction for EpCAM, EMA, PAX8 and ER. Two cysts had cuboidal to flattened lining, the cells of which were diffusely or focally positive for mesothelial markers, for some epithelial markers (eg. EpCAM and EMA) and despite a lack of müllerian-type epithelium demonstrated a positive reaction for PAX8 and focally for ER. A cyst derived from adreno-hepatic fusion (AHF)-related intra-adrenal bile ductules was diagnosed in a right adrenal gland which was directly adherent to the liver, microscopically features of AHF were visible with intermingling of adrenal and liver parenchymal cells. The immunoreactivity pattern was similar among the preserved cells of the cyst-lining, the intra-adrenal bile ductules and the normal bile ductules in the adjoining liver parenchyma. On the basis of this case series from a single institution (8 presented now and 1 reported before) we propose a new histogenetic categorization of adrenal epithelial cysts into: 1. pure mesothelial cysts (the most common type), 2. mesothelial cysts with incomplete or complete müllerian metaplasia 3. AHF-related cysts.

Laparoscopic resection of an adrenal pseudocyst mimicking a retroperitoneal mucinous cystic neoplasm

Adrenal pseudocysts are rare cystic masses that arise within the adrenal gland and are usually non-functional and asymptomatic. Adrenal pseudocysts consist of a fibrous wall without a cellular lining. We report a patient with a 9 cm, left-sided suprarenal cystic mass who presented with abdominal discomfort of 2 years’ duration. A 38-year-old woman was referred to our service for evaluation of abdominal discomfort and gastrointestinal symptoms. Routine laboratory tests were within normal limits. An abdominal computed tomography scan showed a 9 cm × 8 cm × 8 cm well-defined cystic lesion displacing the left kidney. Magnetic resonance imaging showed a cystic lesion with low signal intensity on the T1-weighted image and high signal intensity on the T2-weighted image. A laparoscopic left adrenalectomy was performed to diagnose the lesion. The final pathology showed an adrenal pseudocyst without a cellular lining. The patient had no postoperative complications and she was discharged four days after surgery.

True adrenal mesothelial cyst in a patient with flank pain and hematuria: a case report

True mesothelial (epithelial) cysts in the adrenal gland are rare lesions. They represent 9% of adrenal cysts and are much less common than vascular adrenal cysts. We report a case of a true adrenal mesothelial cyst in a patient with flank pain and hematuria that was diagnosed on imaging as a renal cyst. Immunohistochemical studies were performed to investigate the nature of the cyst lining. The positive immunostains for calretinin and WT-1 lend support to the postulate of Medeiros et al nearly 20 years ago of a mesothelial origin for these cysts. The clinical presentation and salient radiologic and pathologic features are described.

Adrenal cystic lesions: a clinicopathological analysis of 25 cases with proposed histogenesis and review of the literature

Adrenal cystic lesions are uncommon and we analyzed clinical and pathologic features of 25 such cases from a single institute over 23 years. There were 16 pseudocysts, eight endothelial cysts, and one epithelial cyst. Seven of eight endothelial cysts were confirmed to be lymphangiomatous by D2-40 immunostaining. We suggest that pseudocysts and endothelial cysts may have different histogenesis. The proposed mesothelial origin of adrenal epithelial cyst cannot be confirmed in our example. Seven adrenal pseudocysts were associated with tumor, including two pheochromocytomas, one neuroblastoma, one adrenal cortical carcinoma, one adrenal cortical adenoma, one myelolipoma, and one schwannoma. The distinction of true cystic lesion from cystic neoplasm is important and requires thorough sampling of the specimens.

Accessory liver lobe with mesothelial inclusion cysts in an omphalocele: a new malformative association

Mesothelial inclusion cysts represent benign lesions that have been reported in a wide variety of locations. Peritoneal cysts are observed and visceral involvement has been described, notably of intraperitoneal organs such as the spleen and the testis. We report the cases of 2 neonates who underwent surgical management of an omphalocele. The hernial sac contained an accessory liver lobe, displaying in both cases multilocular mesothelial inclusion cysts. The hobnail cells lining the cysts exhibited calretinin and cytokeratin immunohistochemical reactivity, as well as focal D2-40 reactivity. One of the cases occurred in the setting of a Beckwith-Wiedemann syndrome (MIM 130650), an overgrowth disorder notably associated with omphalocele and hepatic anomalies and tumors. However, no hepatic mesothelial cyst has been described in this syndrome. In the 2nd case the omphalocele and the hepatic cysts were the sole lesions observed in the neonate. To the best of our knowledge, these 2 cases represent the first description of such an association.

Adrenal cyst: a review of the Japanese literature and report of a case

Adrenal cysts are a rare condition and are usually non-functioning and asymptomatic. A 44-year-old man was referred from another hospital because a left retroperitoneal tumor was incidentally found by abdominal echography. Laboratory findings including adrenal hormonal study were within the normal range. It showed homogeneously low intensity on T1-weighted images and high intensity on T2-weighted images on magnetic resonance imaging (MRI). Angiography demonstrated that the tumor was avascular and of left adrenal origin. The patient was diagnosed with left adrenal cyst and was intensively followed up with plans for examination with diagnostic imaging.

Management of Adrenal Cysts

Adrenal cysts have been traditionally managed by excision to rule out malignancy. We reviewed the 613 cases of adrenal cysts (including 6 new cases of our own) to evaluate whether this is still appropriate. Descriptive statistics and distribution of each pathologic type have been updated, based on 515 cases, and have changed from statistics compiled on 155 cases by G. A. Absehouse et al. Only seven per cent of all adrenal cysts are malignant or potentially malignant. There is only one reported case of a malignancy found in a nonfunctioning adrenal cyst that was initially thought to be benign. In this case, no CT or aspiration was performed. There have been 19 cases of adrenal cysts managed with aspiration. All were nonfunctioning and benign. One had a bloody aspirate. Reaccumulation occurred in 32 per cent of the cases (six cases); six per cent were symptomatic, four per cent were excised. Follow up was available in 15 cases from 4 months to 3.5 years. Management of the patient with a suspected adrenal cyst should include a careful history and physical and biochemical screening to rule out a functioning lesion. A CT scan, and aspiration of the cyst with a cystogram should be performed to confirm a simple cyst of the adrenal. If the suspicion of malignancy is low, and the lesion is nonfunctional, the adrenal cyst may be managed by aspiration alone. If the cyst recurs and is asymptomatic, it may be observed. If a symptomatic cyst recurs, it may be reaspirated or excised.

Adrenal cortical epithelial cysts in two saddleback tamarins (Saguinus fuscicollis)

Adrenal cysts of epithelial origin were found incidentally in the adrenal cortical tissues of two adult female saddleback tamarins. In one case, a small cluster of minor cysts was located at the cortico-medullary border. The cysts were filled with a periodic acid-Schiff (PAS)-positive, amorphous substance and lined by a cuboidal PAS-negative epithelium, which resembled morphologically the ascending Henle's loops of the kidney. These microcysts were thought to be mesonephric remnants. In the second case, two large cysts of 1 to 3 mm diameter extended throughout the entire cortex. The cysts were filled by a watery, PAS-negative fluid and lined by a bi- to multi-layered, cytokeratin-positive epithelium. The basal epithelial layer consisted of cuboidal cells, which became cylindrical to drop-like in appearance towards the cyst lumen. The cysts closely resembled mesothelium-derived adrenal cysts in man. This is the first report of adrenal cysts in non-human primates.