Key words Askin tumor; clinical features; pathological features

1 Clinical data

    Patients, male, 9 years old, was admitted to hospital on January 15, 2007, because of “the right side of the chest wall lymphoma recurrence. The patients had the end of 2005, in January due to the right side of the chest pain associated with paroxysmal dry cough, and sometimes chest tightness, shortness of breath, stay outside the hospital. Examination see right anterior chest slightly raised, with mild tenderness obviously enlarged mediastinal shadow on chest showed enhanced chest CT See mediastinal placeholder consider lymphoma possible. January 9, 2006 in the hospital line mass resection, postoperative pathological diagnosis of lymphoma, untreated. 1 year right anterior chest uplift, accompanied by persistent pain. Hospital CT scan shows: the right anterior chest wall two placeholders, about the size of 6.5cm × 6cm × 5cm and 3cm × 3cm × 2cm prompted lymphoma recurrence after hospitalized.

    Admission examination: body temperature 37.1 ° C, pain sickly, passive posture the investigation right anterior chest subcutaneous hemispherical uplift, about 7 cm x 8 cm, the pressure of pain, a little sense of volatility, lungs no rales, heart rate of 100 beats / min , legal Qi. The line “tumor exploratory surgery on January 17, 2007. Intraoperative frozen section examinations showed malignancy, and thus the line “mass extended radical mastectomy. Intraoperative findings about 3cm × 2cm × 3cm size tumors rely on second costal cartilage at the junction of the midline and right, closely linked with the ribs, showed a cystic growth to the chest, and about the size of 6cm × 6cm × 5cm tumor package around the right front edge of the second rib growth along the right second intercostal space to the chest wall, showed a cystic wall is thin, easily broken, pale yellow liquid outflow, infiltration of the second rib was moth-eaten changes. Were observed: The tumor cells were small round or oval, more uniform in size, less cytoplasm, the nucleolus and more obvious, visible irregular mitosis. The piece was massive, nested and lobular and rosettes structure visible around the central transparent pink dye formation. Immune phenotype as follows: the tumor cell membrane CD99 (MIC2) positive, NSE and S  100 was cytoplasmic CD45, Vimentin and Cytokeratin were negative. Pathological diagnosis: Askin tumor infiltration into striated muscle and ribs. Immunohistochemical results consistent with those reported [1  2]. Postoperative chest radiographs a week: the right side of a small amount of pneumothorax. February 18, 2007 once intravenous chemotherapy (chemotherapy THP than the star, cyclophosphamide, vincristine) local radiotherapy DT: 40Gy pain relief. During chemotherapy reactions are mild, review the blood, liver and kidney function, electrolytes are normal. Hospitalized 61 days later improved and was discharged.

  2 Discussion

1979 Askin [3] first reported malignant small cell tumor of the soft tissue of the chest area group is one of PNET / Ewing sarcoma family. Occurs in children and adolescents, more common in girls, the male to female ratio 1: (3 to 4), with an average age of 14.5 years, mainly as the chest wall and the lung tumor patients, may have chest pain, fever, chest tightness, shortness of breath, coughing and other symptoms . Generally believed that its high malignancy and poor prognosis. Reported 5-year survival rate of the patients had been diagnosed less than 20% to 30%, the patient died of local recurrence and metastasis general, more common blood metastasis [4  5]. CT, MRI examination can show the tumor size, scope and relationship with the adjacent organs. But no characteristic performance is difficult to identify with other breast tumors. The clinical diagnosis depends on pathology, immunohistochemistry and electron microscopy analysis [6]. The differential diagnosis of small round cell tumor differences: (1) small cell carcinoma: rosettes structure epithelial markers such as EMA and Cytokeratin positive; (2) malignant lymphoma: the unity of lymphocyte growth characteristics CD45 T cells or B cells, such as flag-positive; (3) malignant rhabdoid tumor: nucleolus is usually obvious inclusion body-like material within the cytoplasm, if conditions do chromosome visible chromosome Genotyping and Askin tumor ; mesothelial (4) small cell sarcoma: crack-like structure phenotype goes to the skin and mesenchymal the bidirectional expression [1]. The Askin tumor tumor is large, often isolated nodules and leaf, no capsule, soft and brittle, gray cut fish-shaped, often accompanied by hemorrhage and necrosis, may have calcification [2,4,6]. This case, removal of tissue, the naked eye cystic capsule, thin wall, and break, pale yellow liquid outflow, and documented different. Therefore, to explore the Askin tumor variations exist, can provide the basis for the anatomical images to identify and individualized treatment.