Difficulties in diagnosis and pathological analysis
preoperative crude needle puncture tissue is limited, Immunohistochemical β catenin tumor cell membrane and cytoplasm positive expression, No nuclear expression was observed, No definitive extramedullary hematopoietic tissue was seen, Hepatoblastoma and hepatocellular carcinoma were positive for all the tumor cells, including AFP, CD 10, Glypican3, and CK 8 / 18, All showed sinusoidal vessels, The more difficult identification between the two is made, The "light and dark" structure is faintly seen in the puncture tissue, And in this case, the child is 5 months old, Neither the child himself nor their mother had a history of hepatitis, Hepatocellular carcinoma mostly occurs in older children, And the tumor cell proliferation index is as high as 45%, If the proliferation index of highly differentiated hepatocellular carcinoma is slightly higher than that of normal liver, Greater than 4% and less than 10%, Comprehensive clinical history, imaging, morphology, and immunohistochemistry, The cture histopathology was considered as hepatoblastoma.
Surgical specimen tissue, besides the morphology seen in the puncture tissue, shows extramedullary hematopoietic tissue by immunohistochemical markers TdT and CD 71, and extramedullary hematopoiesis is rare in hepatoblastoma. It seems unlikely that hepatoblastoma cells themselves undergo a transition to HSC cloning【2】, Because diffuse positive CK8 / 18 expression in tumor cells was marked by epithelial cell differentiation. It is conceivable that hematopoietic stem cells migrate from the yolk sac to the liver in early fetal life【3】Can be preserved in the appropriate environment of the transformed fetal liver tissue, and this point may be the case where hepatoblastoma occurs in the abdominal cavity【4】. Extramedullary hematopoiesis occurs mainly in hematological tumors, but can also occur in patients with breast, lung, kidney, colon, gastric, pancreatic, or prostate cancer【5】。
Puncture tissue β catenin cell membrane and cytoplasm, surgical specimens mixed cell membrane, cytoplasm, and nucleus, β catenin in normal fetal cells and immature cells in the nucleus.
differential diagnosis analysis
Hepatocellular carcinoma: liver plate thickening, generally more than 2 layers, different cell morphology, there is no light and dark structure, extramedullary hematopoiesis; most of the patients with hepatocellular carcinoma are older children, and children or mothers of children have a history of hepatitis B virus infection, and cirrhosis can be seen on imaging examination.
Mixed epithelial mesolobar hepatoblastoma: composed of epithelial and mixed neoplastic mesostilobar components, most tumors contain mature and immature fibrous tissue, bone or bone-like tissue.
Focal nodular hyperplasia: stellate scar with radial fibers separated in the center of the lesion【6】, There are often thick-walled blood vessels in the fiber septum, and the hepatocyte morphology of nodular hyperplasia is no different from that of normal hepatocytes, the gross tissue texture is tough, and the network fiber structure is complete.
Liver teratoma: two or more germ tissues can be seen, showing differentiation into different germ layers.
Hepatocellular adenoma: common in women aged between 20 and 40, related to the use of oral contraceptives, male hormone therapy and glycogen hoarding. It consists of transparent and differentiated hepatocytes with consistent size and morphology, no nuclear division, no duct area and central vein in the tumor.
Analysis of treatment and prognosis
At present, the multidisciplinary diagnosis and treatment with surgery and combined chemotherapy has become the standard model of hepatoblastoma treatment【7】In this case, COG Evans stage Ib; the clinical risk group belongs to the low-risk group. For the timing of hepatoblastoma surgery, the protocol varied between different collaborative groups. The Pediatric Oncology Collaborative Group (Children’s Oncology Group, COG) patients with stage PRETEXTI and stage may undergo primary resection without preoperative chemotherapy【8】。