A case of adrenal lymphangioma successfully treated with laparoscopic partial adrenalectomy

Introduction Adrenal lymphangioma is a rare benign tumor of lymphatic origin, usually incidentally detected from various imaging studies taken for an unrelated purpose. We present a case of a right adrenal lymphangioma treated successfully with surgical intervention. Case presentation A 36‐year‐old previously healthy woman was referred to our urology department for a right adrenal mass, discovered during a routine health checkup. The tumor had no endocrinological activity, and the patient opted for surgical resection following a concern for malignancy. A laparoscopic right partial adrenalectomy was performed, and on histological examination, the tumor was diagnosed as right adrenal lymphangioma. Conclusion Adrenal lymphangiomas lack disease specific radiological characteristics that allow for a definitive diagnosis from imaging alone. To rule out tumors of potentially malignant nature, surgical intervention should be considered.


Introduction
Adrenal lymphangioma is a rare benign tumor of lymphatic origin.Whereas most lymphangiomas are found during infancy, usually in the cranial region, adrenal lymphangiomas are mostly detected incidentally during adulthood from various imaging studies.Here, we report a case of a right adrenal lymphangioma successfully treated with laparoscopic partial adrenalectomy.

Case presentation
A 36-year-old previously healthy woman was referred to our hospital for a right cystic adrenal mass, which was discovered incidentally during her routine medical checkup.A contrast CT scan showed a poorly enhanced 5 cm solitary mass on the right adrenal gland, with a polycystic appearance with some calcification (Fig. 1).On MRI, the mass was uniformly hypointense on T1 weighted image (Fig. 2a), and hyperintense on the T2 weighted image (Fig. 2b).An endocrinological workup was performed prior to referral, with no detectable abnormalities, suggesting a non-functioning adrenal mass.
The patient opted for surgery from her concerns about a possible malignancy, or future hemorrhage.
The surgery was performed under general anesthesia in the left semi-lateral decubitus position.A 12 mm laparoscopic port was positioned slightly lateral from the right midclavicular line, 3 cm caudal from the ribcage.A 5 mm port was placed on the same axial plane, on the right midclavicular line for the right-hand access, and on the anterior axillary line for the left hand.A 5 mm assistant port was placed caudally from the xyphoid.
The tumor had a round, polycystic appearance, with clear visible margins with the adrenal gland (Fig. 3a,b).The lack of adhesions between the tumor and surrounding tissue was strongly suggestive of a benign tumor, and an intraoperative decision for a partial adrenalectomy was made.A complete resection of the tumor was performed with much of the functioning adrenal gland left intact.The operation time was 1 h 53 min, with 5 mL blood loss, and the patient was discharged 4 days post-surgery.On cross-section, the tumor was polycystic, containing a clear, serous substance.
Histologically, on H&E staining, fibrotic cysts containing calcifications were observed, with clear borders with the normal adrenal tissue (Fig. 4a,b).On immunohistochemistry, the endothelial cell lining of the cyst wall was stained positive for D2-41 and CD31, a phenotype characteristic of lymphatic tissue, together suggestive of the final diagnosis of adrenal lymphangioma (Fig. 4c,d).

Discussion
Lymphangiomas are benign tumors originating from the lymphatic system, majority of which are found during infancy,  commonly in the cranial and axillary regions. 1 Lymphangiomas found during adulthood are relatively rare, usually discovered incidentally as an intraabdominal or retroperitoneal mass during routine medical checkups or imaging for other unrelated purposes. 2,3drenal lymphangiomas are therefore a rare occurrence, although there is an increase in its reported incidence, presumably owing to the advancement and availability of various imaging modalities. 4To the best of our knowledge, fewer than 70 cases have been reported in the English literature.Its precise mechanism of pathogenesis is unknown, although causes such as congenital abnormalities of lymphatic drainage and lymphatic congestions due to trauma or inflammations have been hypothesized. 1Most lymphangiomas are asymptomatic, although incidences where these tumors were discovered after symptoms such as abdominal pain, palpable abdominal mass, hemorrhage, and infections have been reported. 1,2Some have also reported adrenal lymphangiomas accompanied by abnormal hormonal secretions, presumably due to compression of the adrenal artery or medulla. 5Ellis et al. observed that these tumors are more frequently found in women, and more commonly seen in the right adrenal gland. 1 As it was the case for this patient, on a histological level, lymphangiomas are often seen on H&E staining as polycystic lesions lined with endothelium-like cells. 1,2,4mmunohistochemistry is also a very useful tool to confirm the tumor's lymphatic origin.We utilized CD31 and D2-40, which are specific markers used to detect tissues of lymphatic linage.Other useful markers may include CD34, factor VIIIrelated antigen, and PROX1. 1,2,6ymphangiomas lack specific radiological characteristics that allow for differentiation on imaging alone. 1Other cystic adrenal lesions with a similar radiological appearance that would require consideration include adrenocortical adenoma or carcinoma, pheochromocytoma, myelolipoma, neuroblastoma, schwannomas, and ganglioneuromas. 1,2,4 Surgical excision may be the management of choice for symptomatic or large adrenal lymphangiomas. 1,2,4Percutaneous aspiration of the cysts may be useful for diagnosis, though not for therapeutic purposes, since it is likely to recur. 1 In practice, the lack of specific radiological characteristics of this tumor means that surgical excision serves both a therapeutic and diagnostic purpose.
Due to its rarity, the precise malignancy potential of a cystic adrenal mass is not well established, and few retrospective case series have been published.Chien reported 7 out of the 25 surgically treated cystic adrenal lesions were associated with a neoplasm (two pheochromocytomas, and single cases of neuroblastoma, myelolipoma, cortical adenoma, schwannoma, and cortical carcinoma), of which two were malignant. 7In addition, there is evidence to suggest that pre-surgical diagnoses of these lesions may often be inaccurate.In cases of large-size cysts (20 cm <), the accuracy rate may be as low as 14.8%. 4Considering data from these reports, a diagnostic excision of these tumors seems reasonable in medical practice.
The prognosis of adrenal lymphangiomas post-surgery seems to be extremely good, as we were unable to find cases that reported post-surgical relapse.

Conclusion
We report a case of a cystic adrenal lymphangioma successfully treated with laparoscopic partial adrenalectomy.This rare and benign tumor of lymphatic origin should be included in the differential diagnoses of adrenal tumors.The potential malignant nature of a tumor should always be considered during the assessment of adrenal cystic tumors.

Fig. 1
Fig. 1 Contrast CT scan, coronal section.Right adrenal cystic tumor with calcifications shown in red dashed circle.