Cystic lymphangioma of the stomach with marked reactive changes: a rare cause of gastric outlet obstruction in adult

Abstract

Cystic lymphangiomas are benign lymphatic tumours which usually affect the paediatric population and are predominantly located in the head and neck region. Its occurrence during adulthood and an intra-abdominal location are both extremely uncommon. Clinically and radiologically, these lesions often mimic malignancy. Infrequently, these tumours can undergo degenerative and reactive changes obscuring the diagnostic features. We describe hereby an anecdote of cystic lymphangioma with marked reactive changes presenting with the features of gastric outlet obstruction in an adult patient.

Background

Cystic lymphangiomas are benign lymphatic tumours usually occurring in the paediatric age group, accounting for approximately 90% of cases. This tumour is extremely rare in adults. Approximately 95% cases are located in the head and neck region and axilla.¹ Only a minority of cases are located in the mesentery, retroperitoneum, abdominal viscera, lung and peritoneal cavity. There are only a few reported cases of cystic lymphangioma arising from the stomach.^2–4 The clinical presentation is diverse regardless of the age of presentation and sites. Most of these lesions are detected incidentally, or less commonly present with chronic abdominal discomfort, nausea and vomiting. An accurate preoperative diagnosis of abdominal cystic lymphangiomas, especially in an adult patient is uncommon owing to its rarity and diverse clinical and radiological features. Some of the reported cases show florid reactive and inflammatory changes that often obscure the lymphatic nature of the tumour and mimic various other benign and malignant mesenchymal lesions, which are far more common in this particular location.⁵ In this report, we depict one such case of cystic lymphangioma arising from the greater curvature of the stomach with marked reactive and inflammatory changes.

Case presentation

A 65-year-old male patient presented to the surgical outpatient department with the complaints of abdominal pain and intermittent vomiting for 2 months. The abdominal pain was epigastric in location, intermittent in nature and was usually associated with food intake (postprandial). The vomiting was intermittent, usually associated with food intake and was non-bilious in nature. There was no history of haematemesis, melaena, jaundice or fever. On examination, a lump was palpable in the epigastric region, which became more prominent after eating. There was no evidence of pallor, icterus, clubbing, oedema, cyanosis or any lymphadenopathy.

Investigations

Ultrasound examination revealed a mass lesion (8×6×5 cm³) in the right upper quadrant of the abdomen posterior to the stomach. Unfortunately, we could not perform endoscopic ultrasonography (EUS) in the present case owing to the unavailability of this instrument in our institute when the patient was admitted. The patient twice underwent ultrasound-guided fine-needle aspiration (FNA) outside which were reported as inadequate and spindle cell tumour, respectively. We could not review these FNA slides. An upper gastrointestinal endoscopy was performed in our institute which revealed antral bulge with near-total gastric outlet obstruction. The overlying mucosa was apparently normal.

Contrast-enhanced CT scan demonstrated a mass lesion posterior to the antrum, inseparable from the stomach but separate from the pancreatic head (figure 1). Based on the radiological features and spindle cell morphology in FNA, a clinical (preoperative) diagnosis of gastrointestinal stromal tumour (GIST) was considered. The differential of gastric carcinoma was also thought of.

Figure 1.

Contrast-enhanced CT scan showing a mass lesion posterior to the antrum, Inseparable from the stomach but separate from the pancreatic head.

The antrectomy specimen showed a relatively circumscribed lesion attached to the posterior aspect of the greater curvature measuring 6×3×2.5 cm³. The external surface of the lesion was nodular. The cut surface of the lesion showed large areas of haemorrhage and fibrosis. Besides, multiple small cysts (1–3 mm in maximum diameter) containing clear fluid were also identified. Some of the cystic spaces also contained blood clot. No characteristic chylous fluid was identified. The lesion appeared to arise from the external aspect of the muscularis propria. However, no frank invasion into the adjacent structure was identified (figure 2A).

Figure 2.

(A) Gross photograph showing a lesion attached to the greater curvature of the stomach. Cut surface is variegated with areas of cystic change, haemorrhage and fibrosis. (B–F) Photomicrographs showing a lesion comprising of dilated cystic channels filled with proteinaceous material, involving the muscularis propria of stomach (B, H&E 40×). Focally the tumour showed lymphatic channels lined by flattened cells and wall containing lymphoid follicles (C, H&E 100×). Other areas showed fresh and old haemorrhage with smooth muscle proliferation (D, H&E 100×), storiform fibrosis (E, H&E 100×) and fat necrosis with giant cell reaction (F, H&E 100×).

Microscopical examination revealed a lesion involving the outer aspect of the muscularis propria. Focal areas showed multiple irregular cystic spaces lined by flattened endothelial cells. Some of the cysts contained homogeneous eosinophilic material (lymph) with numerous lymphocytes. The cyst wall showed fibrosis and focal presence of lymphoid follicles. These classical features of lymphangioma were present only focally (approximately 10% areas). The other areas constituting a major proportion of the specimen showed marked reactive changes. There was fibroblastic and myofibroblastic proliferation with intercellular collagen deposition. Focal areas showed a storiform arrangement of the fibroblastic cells with the proliferation of smooth muscle cells. Areas of old haemorrhage with numerous haemosiderin-laden macrophages and focal inflammatory granulation tissue formation were also noted. Also, areas of fat necrosis with infiltration by sheets of foamy histiocytes and foreign body giant cells were seen. No mitotic activity or necrosis was identified (figure 2B–F). The endothelial cells of the lymphatic vessels were immunopositive for CD31 and CD34. The myofibroblastic proliferation showed focal positivity for smooth muscle actin (SMA). Immunostains for CD117 and DOG-1 were negative. The lymph node resected, along with the antrectomy specimen showed reactive changes. There was no evidence of any lymphatic disease.

Perioperatively a small nodule was also identified (5 mm in maximum dimension) over the serosal aspect of the jejunum. Sections examined from this jejunal nodule showed histomorphological features of leiomyoma. The tumour cells were immunopositive for SMA while negative for CD117 and DOG-1.

Differential diagnosis

Based on the clinical and radiological features, the possibility of a malignant lesion arising from the stomach was considered, including GIST and gastric carcinoma. However, the histopathology was characteristic of cystic lymphangioma which ruled out the possibilities of any malignancy and clinched the diagnosis.

Treatment

The patient had undergone antrectomy with the removal of perigastric lymph nodes as the suspicion of the malignant tumour was high. Nevertheless, as the diagnosis turned out to be cystic lymphangioma, no further treatment was required.

Outcome and follow-up

The patient had an uneventful recovery in the postoperative period. The patient is on follow-up for more than a year now, and there is no recurrence of the disease.

Discussion

Cystic lymphangioma is a slow-growing benign neoplasm that usually arises due to acquired or congenital failure of the lymphatic channels and subsequent proliferation of the lymphatic spaces. The acquired condition is more common in adults and may be related to inflammatory conditions or physical trauma, such as created by surgical or radiation therapies.^{6 7} However, no such attribution was identified in the present case.

Although rarely reported, some of the cases of cystic lymphangioma may undergo marked superimposed reactive and inflammatory changes in the surrounding tissue. In these cases, their lymphatic nature may be obscured, and some cases clinically and pathologically mimic other malignant tumours. Hornick and Fletcher⁵ had reported seven such cases which showed florid reactive or inflammatory changes in the form of myofibroblastic proliferation resembling desmoid fibromatosis or nodular fasciitis and extensive xanthogranulomatous inflammation. Interestingly, none of these cases were diagnosed correctly on preoperative evaluation. Further, two of these cases were diagnosed as sarcoma. Similarly, the present case also showed fibroblastic and myofibroblastic proliferation, along with focal xanthomatous changes. Besides, there were areas of old haemorrhage and fat necrosis. Preoperatively this case was diagnosed as GIST, possibly due to its location and the spindled morphology on FNA.

Clinically and radiologically, cystic lymphangioma needs to be distinguished from other cystic retroperitoneal lesions, including abscess, cystic lesions of pancreas, cysts of foregut/urothelial origin, ovarian cystic tumours, malignant tumours or metastasis with cystic degeneration, teratoma, duplication cyst, etc.^{8 9} Although such distinction is more often difficult without histopathology. Hence, the histopathological examination is the gold standard for such a diagnosis. Even histologically also, cystic lymphangioma with a significant degenerative change in the form of fibroblastic and myofibroblastic proliferation can mimic other spindle cell lesions. These include sclerosing mesenteritis, inflammatory myofibroblastic tumour, GIST, leiomyoma, leiomyosarcoma and liposarcoma. Identification of the lymphatic component is most important for its correct diagnosis, although in most of these cases it can be only focally present. Hence, extensive sampling of the specimen is crucial. Also, the use of immunohistochemical panels, including D2-40, CD31 and CD 34 may be of great help.

EUS is one of the important diagnostic modalities for lesions arising from the gastric wall. However, the EUS features of gastric lymphangioma is not well elucidated, possibly owing to its rarity. Some of the available reports have described it as a submucosal well-circumscribed anechoic lesion with internal septa.^10–12 However, the internal echo pattern depends on the size of the lymphatic channels. One of the gastric lymphangioma with the lymphatic channel of <1 mm size showed a homogeneous echo pattern.¹¹ Contrast-enhanced CT showed a heterogeneously enhancing solid mass with the focal cystic area. This finding is unusual for a classical lymphangioma and is related to the superimposed reactive changes.

Another unique feature of the present case was the coexistence of a jejunal leiomyomatous nodule mimicking metastasis. Intraoperative histological examination is helpful in these cases for the judicious determination of the extent of surgical resection.

Learning points.

• Cystic lymphangioma arising from the greater curvature of the stomach in an adult is extremely rare and diagnostically challenging.

• These cases may be associated with superimposed reactive and inflammatory changes, which often mask the true lymphatic nature of the tumour.

• Awareness and high index of suspicion along with a meticulous sampling of the specimen and histological examination are essential for a definitive diagnosis.

• Intraoperative histological examination to determine its benign nature may be useful to avoid surgical overtreatment.