A histopathological diagnosis of mesenteric cystic lymphangioma, clinically misdiagnosed as simple mesenteric cyst - case report.

Abdominal cystic lymphangiomas are relatively rare congenital malformations, predominantly found in the pediatric age group. They are usually found in the head and neck of affected children. Lymphangioma of the small-bowel mesentery is rare, having been reported for less than 1% of all lymphangiomas. The gross and histopathological findings may resemble benign multicystic mesothelioma and lymphangiomyoma. The immunohistochemical study for factor VIII-related antigen, D2-40, calretinin and human melanoma black-45 (HMB-45) is essential for diagnosis. Factor VIII-related antigen and D2-40 are positive in lymphangioma but negative in benign multicystic mesothelioma. HMB-45 shows positivity in the smooth-muscle cells around the lymphatic spaces of the lymphangiomyoma. This report describes a case of a large mesenteric lymphatic cyst identified in the neonatal period. Early diagnosis was possible due to the prenatal imagistic methods. Fetal ultrasound identified in the 17th week of gestational life an abdominal tumor that increased with fetal growth. The anatomopathological differential diagnosis and modalities of treatment are also discussed.

Indications and limitations of histopathological skin investigation of Henoch-Schönlein purpura in children.

UNLABELLED: Henoch-Schönlein purpura, the most common primary vasculitis of the child, may cause, in some cases with atypical clinical picture, diagnostic difficulties with a significant prognosis impact, especially when occasionally "silent" renal symptoms coexist. The purpose of our study is, on one hand, to determine the histopathological investigation needs of Henoch-Schönlein purpura in children with atypical cutaneous manifestations or incomplete forms of illness and, on the other hand, to point out the correlation between the cutaneous histopathological aspects and other clinical and biological manifestations. RESULTS: Optical microscopy revealed signs of leukocytoclastic vasculitis in 11 of the 22 cases with ulcerative necrotic purpura and atypical clinical picture. Immunohistochemical examination proved that these were associated with IgA deposits on the vascular wall, sometimes accompanied by C3, fibrin, IgM and CD3. The severity of the skin manifestations was directly correlated with the severity of digestive and/or renal symptoms. CONCLUSIONS: Skin biopsy is indicated only in the atypical or incomplete forms of disease to support positive diagnosis by immunohistochemical evidence of the vascular IgA deposits. The severity and persistence of the ulceronecrotic purpuric rash seems to be directly related rather to the severity of the other clinical manifestations (digestive or renal) than to the generalized extensively purpuric appearance.