Peri-Hilar Cystic Lymphangioma Mimicking a Biliary Cystic Lesion Causing Biliary Obstruction: A Case Report and Literature Review

Background

Lymphangiomas are rare and benign malformations of the lymphatic system that result from a congenital or acquired abnormality. The congenital form typically occurs in young children, with the majority found extra-abdominally, such as in the head, neck, and axilla. The acquired form presents in adulthood, with the majority localized to the mesentery of the large or small bowel, caused by interruption of the normal lymphatic drainage system secondary to surgery, trauma, malignancy, or radiation therapy. Lymphangiomas in adults typically present as asymptomatic lesions and are often less than 4 cm in size. However, large-volume tumors of up to 20 cm have been described [1]. A large tumor volume usually causes abdominal pain and can cause intestinal obstruction [2]. The treatment is mainly surgical and consists of complete resection when feasible. We present a case of lymphangioma arising from within the hepatoduodenal ligament mimicking a biliary cyst and causing an extra-hepatic and intrahepatic biliary dilatation. To the best of our knowledge, this is the first reported case of hepatoduodenal lymphangioma causing biliary obstruction. In this article, we review the pathophysiology, histopathology, diagnostic evaluation, and management of intra-abdominal lymphangiomas.

Case Report

The patient was a 62-year-old man with a history of laparoscopic cholecystecomy, T2N0M0 prostate cancer status after robotic radical prostatectomy with bilateral pelvic lymph node dissection, in addition to T1NxM0 bilateral renal cell carcinoma status after bilateral partial nephrectomy, who presented to the hepatobiliary clinic for an increasing peri-hilar cystic lesion identified on a surveillance magnetic resonance imaging (MRI). The patient’s MRI revealed a 5.5×4.3 cm cystic lesion at the peri-hilar region, likely arising from the biliary tree and causing intrahepatic and extrahepatic biliary dilatation. In an imaging study obtained 6 months earlier, the lesion measured 4.2×4.2 cm (Figure 1) with no evidence of extrinsic compression of the biliary tree. Complementary blood work did not demonstrate biochemical obstruction of the biliary tree (total bilirubin 0.5, direct bilirubin 0.2, alkaline phosphatase 80). Clinically, the patient was asymptomatic. Following the noted increase in the lesion size with radiographic evidence of biliary obstruction, the patient underwent an endoscopic ultrasound to better characterize this lesion. The endoscopic ultrasound revealed a 4.3×2.2 cm cystic structure likely arising from the cystic duct stump, with internal septation. An endoscopic retrograde cholangiopancreatography (ERCP) was also performed to delineate the biliary anatomy further. There was no communication between the biliary tree and the cystic lesion. Given the uncertain etiology of the lesion, increase in size of the lesion, and the associated biliary obstruction, the patient was taken to the operating room for excision of the cystic lesion. An open approach was used for excision of the cyst. The cyst was noted to be well-encapsulated and localized between the junction of the cystic duct stump and the common hepatic duct. The lesion did not communicate with the biliary tree. It was circumferentially dissected and elevated medially off of the common hepatic duct and laterally off of the cystic duct stump. The cystic lesion was resected in its entirety, without rupture (Figure 2). He had an uneventful postoperative course, with no evidence of recurrence 3 years after excision. Pathology confirmed the diagnosis of lymphangioma, given the features of large vascular spaces in the background of loose connective tissue stroma, which may contain peripheral lymphoid aggregates (Figure 3). A single layer of flattened endothelial cells demonstrated positive immunohistochemical staining with D2-40 lining the vascular spaces (Figure 4). The immunohistochemical staining was negative for pankeratin, C19.9, CA125, EMA, CEA, calretinin, CK7, and muscle actin.

Discussion

Cystic lymphangioma of the abdominal cavity is a rare disease, especially from within the hepatoduodenal ligament. Approximately 70% of these tumors are found in the mesentery of the small or large bowel [3]. A limited number of reports have documented lymphangioma in the omentum, gastrosplenic ligament, pouch of Douglas, gastrointestinal tract, spleen, liver, kidneys, adrenals, and pancreas.

Congenital or acquired abnormalities of the lymphatic system are the initiating factors causing development of lymphangiomas. Congenital lymphangiomas form due to blockage of the lymphatic system during fetal development resulting in an improper connection of lymphatic channels to the main lymphatic drainage duct [4], whereas acquired lymphangioma occurs because of an interruption in a previously normal lymphatic drainage system as a result of surgery, trauma, malignancy, and radiation therapy. The congenital form predominately occurs in young children, with 90% found extra-abdominally, such as in the head, neck, and axilla [4]. An acquired form of lymphangioma is typically present in adulthood. Our patient represents a case of acquired lymphangioma occurring as a sequela of cholecystectomy, causing an interruption of the previously normal lymphatic drainage system from surgical manipulation.

Histologically, lymphangiomas are classified into 3 types: simple capillary, cavernous, and cystic. The capillary lymphangioma comprises small thin-walled lymphatics, whereas the cavernous lymphangioma consists of larger lymphatics with adventitial coats. Cystic lymphangioma consists of large macroscopic lymphatic spaces that contain collagen and smooth muscle [5]. The differential diagnosis includes cavernous hemangiomas when they show secondary hemorrhage, and biliary cystadenoma. The diagnosis of a lymphangioma over a hemangioma can be favored when there are lymphoid aggregates in the stroma. The diagnosis of biliary cystadenoma over lymphangioma can be preferred when there is evidence of a single layer of cuboidal or columnar epithelium lining the cyst’s wall with glycogen-rich cytoplasm.

Patients can present with varied clinical symptomology. Patients may have abdominal pain or abdominal distention secondary to a large tumor volume of the lymphangioma. Rarely, lymphangioma present with an acute abdomen, which can result from obstruction, perforation, or torsion of the bowel secondary to the large volume of the lymphangioma. In case studies, lymphangiomas have been mistaken for liver hematoma [6], liver cyst [7], ovarian cyst [8], and even metastasis [9].

On ultrasound examination, lymphangiomas are often described as well-circumscribed cystic lesions with thin-walled and multiple thin septa. Sometimes, the cyst is complicated by an intra-cystic hemorrhage demonstrating an echogenic content. On computed tomography, the lesion is homogeneous, hypodense, and with an enhancement of the wall and septa by contrast [10].

An accurate diagnosis of lymphangioma is only possible with histological and immunohistochemical evaluation. Histological evaluation of these lesions will reveal large vascular spaces in the background of loose connective tissue stroma, which may contain peripheral lymphoid aggregates, with a single layer of flattened endothelial cells demonstrating positive immunohistochemical staining with D2-40 lining the vascular spaces. The immunohistochemical staining is negative for pankeratin, C19.9, CA125, EMA, CEA, calretinin, CK7, and muscle actin [11].

Complete excision is the best surgical option to avoid recurrence. Recurrence rates have been calculated to range from 0% to 13.6%, with most of those occurring in retroperitoneal lymphangiomas [12]. Although lymphangiomas are benign lesions, they often behave in an aggressively invasive manner and grow to an enormous size. Therefore, resection of adjacent organs may be required to accomplish complete excision. Furthermore, it is essential to remember that after irradiation, transformation into lymphangiosarcoma is possible [5]. Non-operative management, including intra-cystic sclerotherapy using doxycycline or bleomycin, can be performed for unresectable lymphangiomas [13].

Conclusions

Our report presents a lymphangioma from within the hepatoduodenal ligament that mimicked a biliary cystic lesion, resulting in biliary dilatation. This case represents an acquired lymphangioma occurring as a sequela of cholecystectomy, likely caused by interruption of the previously normal lymphatic drainage system secondary to surgical manipulation.