Unusual presentation of a retroperitoneal lymphangioma
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《美国医学杂志》
Apollo Hospitals, Chennai, India
Abstract
A 3 year old child presented with hemorrhagic ascites of short duration. Based on clinical manifestation and investigations a differential diagnosis of peritoneal tuberculosis, pancreatic ascites or malignant ascites was considered. Laparotomy revealed a huge retroperitoneal cystic lymphangioma confirmed by histopathology. The unusual presentation of retroperitoneal tumours as pseudoascites is discussed.
Keywords: Pseudoascites; Lymphangioma; Multiloculated cyst
Ascites is a term derived from the Greek word " askos" meaning a bag or sac and is a pathological accumulation of fluid in the peritoneal cavity. It is diagnosed clinically by the presence of abdominal distension, bulging flanks, shifting dullness and fluid thrill[1]. The important causes of ascites in children are chronic liver disease, tuberculosis, pancreatic ascites and malignancy. Pseudoascites is a term used when the clinical findings are suggestive of ascites but there is no free fluid in the peritoneal cavity. Ultrasound,CT or MRI abdomen usually help in differentiating true from pseudoascites.[2] Giant omental cysts and mesenteric cysts have been reported masquerading as pseuodoascites. Retroperitoneal cystic lymphangioma are rare benign tumours occurring in children[3] and rarely present as pseudoascites. We are reporting a case of retroperitoneal cystic lymphangioma which became symptomatic following a blunt trauma and presented as pseudoascites.
Case Report
A 3 year old boy was referred with history of progressive distension of abdomen and decreased appetite of 10 days duration. There was no history of abdominal pain, vomiting, fever, pedal edema, jaundice, gastrointestinal bleed, decreased urine output or contact with tuberculosis. There was a history of bicycle handle bar injury one month ago. An abdominal ultrasonogram report of gross ascites with septations was available at the time of presentation.
On examination he was pale, weight was 12 kgs. (expected was 14 kgs). There was no icterus, pedal edema or lymphadenopathy. The abdomen was distended and flanks were full. Few superficial veins were seen over the anterior abdominal wall, Fluid thrill was present and bowel sounds were heard. There was no shifting dullness,hepatosplenomegaly or tenderness on palpation. A differential diagnosis of peritoneal tuberculosis with anemia, pancreatic ascites or malignant ascites was considered based on clinical and sonographic appearance and the child was investigated. The Hb was 6.2 gm/dl, WBC 7400 cells/cumm, platelets 4, 12, 000 cells/cu mm, ESR 42 mm/hr and the reticulocyte count was normal. The peripheral smear showed normocytic, normochromic anemia.Biochemical tests of the liver, coagulation profile and renal parameters were normal. The Mantoux test was negative and chest x-ray was normal. A diagnostic paracentesis revealed an uniformly haemorrhagic fluid which showed numerous RBCs without lymphocytes, AFB or malignant cells. The ascitc fluid amylase was 31 U/L.and adenosine deaminase was within normal limits. Since the fluid was uniformly hemorrhaghic with numerous RBCs a contrast enhanced computerized tomography (CECT) of the abdomen was done. CECT abdomen revealed a huge cystic mass on the right side pushing the bowel loops to the left side Figure1. The child underwent laparotomy and a large retroperitoneal cyst was identified. A frozen section was obtained which was reported as a benign multiloculated cyst suggestive of lymphangioma. The cyst was excised and it contained thick hemorrhagic fluid. The histopathological examination of the cyst wall demonstrated fibrosis, inflammatory cell infiltrate and the presence of endothelial lined vascular channels. These findings confirmed a benign lymphangiomatous cyst and a diagnosis of retroperitoneal cystic lymphangioma with internal hemorrhage was made. The post-operative period was uneventful. He was discharged and the parents were informed about the possibility of recurrence of the lesion.
Discussion
Retroperitoneal cystic lymphangioma is a rare, benign mesodermal tumour arising from the retroperitoneal lymphatics. Lymphangiomas are histologically classified as capillary,cavernous and cystic with the retroperitoneal types being almost always cystic[4]. These cystic lesions may be unilocular or multilocular, contain serous or chylous fluid. The majority (more than 95%) are situated in the head, neck, axilla and extremeties. Other sites including the abdomen are seen only in 5% of cases[4]. The intra abdominal cystic lymphangiomas occur in less than 1 per 100,000 hospital admissions. Retroperitoneal lymphangiomas are rarer than abdominal lymphangiomas of mesenteric origin. The postulated mechanism for the formation of lymphangioma is the early developmental sequestration of lymphatic vessels that fail to establish connection with normal draining vessels at about 14 to 20 weeks of intrauterine life.
Cystic retroperitoneal lymphangioma can present in infancy with 50%to 60% occurring during the first year of life and 90% by second year. They usually present as palpable soft abdominal mass.Though benign they can compress and infiltrate vital structures[5] or present with complications like intracystic hemorrhage, cyst rupture,volvulus or infection.
Pseudoascites as a presentation of retroperitoneal cyst is less common than seen in giant omental cysts, mesenteric or ovarian cysts.The reason for the rarity is probably because these cysts are less common than omental or mesenteric cysts. The other causes of pseudoascites are intrabdominal ecchinococcal cysts, tubular enteric duplication cysts[6] and giant ovarian cysts. The sonographic appearance of a septated cystic mass with clear fluid is supposed to be characteristic of a lymphangioma. However, a pre-operative diagnosis is seldom made in spite of ultrasound and contrast studies. The large size of the lesion may be a factor which poses a problem to differentiate the cyst from ascites.Similar cystic lesions have been diagnosed as loculated fluid collections and treated as tuberculosis.[3] The treatment of retroperitoneal lymphangioma is surgical enucleation. A complete excision of the cyst is mandatory to prevent recurrence. The long term prognosis is excellent if complete excision has been achieved. If not the child should be followed up with serial ultrasound to exclude recurrence of the lesion. An alternative treatment available is image guided percutaneous catheter drainage of lymphangioma followed by sclerotherapy.[5] This report highlights the importance of a complete evaluation when a child presents with abdominal distension and to consider the possibility of cystic lesions in the differential diagnosis of massive ascites.
References
1. Cattau EL, Benjamin SB, Knuff TE et al. The accuracy of physical examination in the diagnosis of suspected ascites. J Am Med Assoc 1982; 247 : 1164-1166.
2. Oray-schrom, Pinar, St. Martin et al. Giant non pancreatic pseudocyst causing anuria. J Clinical Gastroenterology 2002;34 : 160-163.
3. Patel AP, Kothari JM, Shukla RB et al. Retroperitoneal lymphangioma. Ind J Pediatr 1994; 61 : 194-197.
4. Leonidas JC, Brill PW, Bhan I et al. Cystic retroperitoneal lymphangioma in infants and children. J Radiol 1978; 127 : 203-208.
5. Shankar KR, Roche CJ,Carty HM et al. Cystic retroperitoneal lymphangioma: Treatment by image guided percutaneous catheter drainage and sclerotherapy. Eur Radiol 2001; 11 : 1021-1023.
6. Lotan Shilo, Dania Hirsch, Martin Ellis et al. Pseudoascites still a diagnostic pitfall; IMAJ 2001; 3 : 770-771.(Rani D Vimala, Srilakshmi)
Abstract
A 3 year old child presented with hemorrhagic ascites of short duration. Based on clinical manifestation and investigations a differential diagnosis of peritoneal tuberculosis, pancreatic ascites or malignant ascites was considered. Laparotomy revealed a huge retroperitoneal cystic lymphangioma confirmed by histopathology. The unusual presentation of retroperitoneal tumours as pseudoascites is discussed.
Keywords: Pseudoascites; Lymphangioma; Multiloculated cyst
Ascites is a term derived from the Greek word " askos" meaning a bag or sac and is a pathological accumulation of fluid in the peritoneal cavity. It is diagnosed clinically by the presence of abdominal distension, bulging flanks, shifting dullness and fluid thrill[1]. The important causes of ascites in children are chronic liver disease, tuberculosis, pancreatic ascites and malignancy. Pseudoascites is a term used when the clinical findings are suggestive of ascites but there is no free fluid in the peritoneal cavity. Ultrasound,CT or MRI abdomen usually help in differentiating true from pseudoascites.[2] Giant omental cysts and mesenteric cysts have been reported masquerading as pseuodoascites. Retroperitoneal cystic lymphangioma are rare benign tumours occurring in children[3] and rarely present as pseudoascites. We are reporting a case of retroperitoneal cystic lymphangioma which became symptomatic following a blunt trauma and presented as pseudoascites.
Case Report
A 3 year old boy was referred with history of progressive distension of abdomen and decreased appetite of 10 days duration. There was no history of abdominal pain, vomiting, fever, pedal edema, jaundice, gastrointestinal bleed, decreased urine output or contact with tuberculosis. There was a history of bicycle handle bar injury one month ago. An abdominal ultrasonogram report of gross ascites with septations was available at the time of presentation.
On examination he was pale, weight was 12 kgs. (expected was 14 kgs). There was no icterus, pedal edema or lymphadenopathy. The abdomen was distended and flanks were full. Few superficial veins were seen over the anterior abdominal wall, Fluid thrill was present and bowel sounds were heard. There was no shifting dullness,hepatosplenomegaly or tenderness on palpation. A differential diagnosis of peritoneal tuberculosis with anemia, pancreatic ascites or malignant ascites was considered based on clinical and sonographic appearance and the child was investigated. The Hb was 6.2 gm/dl, WBC 7400 cells/cumm, platelets 4, 12, 000 cells/cu mm, ESR 42 mm/hr and the reticulocyte count was normal. The peripheral smear showed normocytic, normochromic anemia.Biochemical tests of the liver, coagulation profile and renal parameters were normal. The Mantoux test was negative and chest x-ray was normal. A diagnostic paracentesis revealed an uniformly haemorrhagic fluid which showed numerous RBCs without lymphocytes, AFB or malignant cells. The ascitc fluid amylase was 31 U/L.and adenosine deaminase was within normal limits. Since the fluid was uniformly hemorrhaghic with numerous RBCs a contrast enhanced computerized tomography (CECT) of the abdomen was done. CECT abdomen revealed a huge cystic mass on the right side pushing the bowel loops to the left side Figure1. The child underwent laparotomy and a large retroperitoneal cyst was identified. A frozen section was obtained which was reported as a benign multiloculated cyst suggestive of lymphangioma. The cyst was excised and it contained thick hemorrhagic fluid. The histopathological examination of the cyst wall demonstrated fibrosis, inflammatory cell infiltrate and the presence of endothelial lined vascular channels. These findings confirmed a benign lymphangiomatous cyst and a diagnosis of retroperitoneal cystic lymphangioma with internal hemorrhage was made. The post-operative period was uneventful. He was discharged and the parents were informed about the possibility of recurrence of the lesion.
Discussion
Retroperitoneal cystic lymphangioma is a rare, benign mesodermal tumour arising from the retroperitoneal lymphatics. Lymphangiomas are histologically classified as capillary,cavernous and cystic with the retroperitoneal types being almost always cystic[4]. These cystic lesions may be unilocular or multilocular, contain serous or chylous fluid. The majority (more than 95%) are situated in the head, neck, axilla and extremeties. Other sites including the abdomen are seen only in 5% of cases[4]. The intra abdominal cystic lymphangiomas occur in less than 1 per 100,000 hospital admissions. Retroperitoneal lymphangiomas are rarer than abdominal lymphangiomas of mesenteric origin. The postulated mechanism for the formation of lymphangioma is the early developmental sequestration of lymphatic vessels that fail to establish connection with normal draining vessels at about 14 to 20 weeks of intrauterine life.
Cystic retroperitoneal lymphangioma can present in infancy with 50%to 60% occurring during the first year of life and 90% by second year. They usually present as palpable soft abdominal mass.Though benign they can compress and infiltrate vital structures[5] or present with complications like intracystic hemorrhage, cyst rupture,volvulus or infection.
Pseudoascites as a presentation of retroperitoneal cyst is less common than seen in giant omental cysts, mesenteric or ovarian cysts.The reason for the rarity is probably because these cysts are less common than omental or mesenteric cysts. The other causes of pseudoascites are intrabdominal ecchinococcal cysts, tubular enteric duplication cysts[6] and giant ovarian cysts. The sonographic appearance of a septated cystic mass with clear fluid is supposed to be characteristic of a lymphangioma. However, a pre-operative diagnosis is seldom made in spite of ultrasound and contrast studies. The large size of the lesion may be a factor which poses a problem to differentiate the cyst from ascites.Similar cystic lesions have been diagnosed as loculated fluid collections and treated as tuberculosis.[3] The treatment of retroperitoneal lymphangioma is surgical enucleation. A complete excision of the cyst is mandatory to prevent recurrence. The long term prognosis is excellent if complete excision has been achieved. If not the child should be followed up with serial ultrasound to exclude recurrence of the lesion. An alternative treatment available is image guided percutaneous catheter drainage of lymphangioma followed by sclerotherapy.[5] This report highlights the importance of a complete evaluation when a child presents with abdominal distension and to consider the possibility of cystic lesions in the differential diagnosis of massive ascites.
References
1. Cattau EL, Benjamin SB, Knuff TE et al. The accuracy of physical examination in the diagnosis of suspected ascites. J Am Med Assoc 1982; 247 : 1164-1166.
2. Oray-schrom, Pinar, St. Martin et al. Giant non pancreatic pseudocyst causing anuria. J Clinical Gastroenterology 2002;34 : 160-163.
3. Patel AP, Kothari JM, Shukla RB et al. Retroperitoneal lymphangioma. Ind J Pediatr 1994; 61 : 194-197.
4. Leonidas JC, Brill PW, Bhan I et al. Cystic retroperitoneal lymphangioma in infants and children. J Radiol 1978; 127 : 203-208.
5. Shankar KR, Roche CJ,Carty HM et al. Cystic retroperitoneal lymphangioma: Treatment by image guided percutaneous catheter drainage and sclerotherapy. Eur Radiol 2001; 11 : 1021-1023.
6. Lotan Shilo, Dania Hirsch, Martin Ellis et al. Pseudoascites still a diagnostic pitfall; IMAJ 2001; 3 : 770-771.(Rani D Vimala, Srilakshmi)