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感谢 重庆三峡中心医院放射科 张莉 整理资料 儿童腹部肿瘤以腹膜后肿瘤的发生率最高，主要来源于肾脏、肾上腺及腹膜后组织，以肾母细胞瘤最常见，其次是神经母细胞瘤、畸胎瘤、神经节细胞瘤、淋巴瘤等,多数为恶性肿瘤。 观察内容：肿瘤的位置、起源、大小 ( 最大径)、边缘 、形态、密度、钙化、强化、局部侵犯、上腹部淋巴结增大、腹膜后血管包埋、血管侵犯、远处转移 。 肾母细胞瘤的假包膜、肿瘤囊变、坏死及肿瘤内丰富血管征象的出现明显高于肾周肿瘤。而肾周肿瘤以神经母细胞瘤最常见 ,其次是腹膜后成熟畸胎瘤及节细胞神经瘤等 ,这些肿瘤常具有特征性的CT征象 ,而成为与肾脏肿瘤的鉴别点 。肾周肿瘤的形态多不规则 ,呈“分叶征”，以腹膜后神经母细胞瘤及非霍奇金淋巴瘤明显；肿瘤内斑片状、细点状、菊团状及块状钙化常见于腹膜后神经母细胞瘤及畸胎瘤；这两种征象的出现高于肾脏肿瘤。此外 ,肿瘤内含脂肪 ,既是畸胎瘤区别于其他腹膜后肿瘤的要点 ,也是肾脏与肾周肿瘤的鉴别点。 肾脏肿瘤以血道转移为主，常发生肺、肝、胸壁及阴道的远处转移 ,下腔静脉或肾静脉瘤栓形成是其特征表现，高于肾周肿瘤的发生，而神经母细胞瘤的远处转移以骨转移为主。 儿童腹膜后肿瘤最多见是神经源性肿瘤，主要包括节细胞瘤、节神经母细胞瘤和神经母细胞瘤。鉴别诊断：要与腹膜后肿瘤如脂肪肉瘤、平滑肌肉瘤、纤维肉瘤、横纹肌肉瘤及腹膜后淋巴瘤、巨大淋巴结增生、特发性腹膜后纤维化、良性纤维组织细胞瘤区分。明确定性诊断需病理证实。 对于儿童腹膜后最常见的两大肿瘤的诊断和鉴别诊断，传统放射学特别是静脉肾盂造影（IVP）有一定价值: 成神经细胞瘤多见钙化 ,晚期出现骨骼转移破坏，静脉肾盂造影显示肾脏以推移改变为主 ; 肾母细胞瘤少见钙化，罕见骨骼破坏，IVP可见肾盂肾盏挤压、破坏, 拉长、变形 。CT较传统X线相比能够提供更多信息,包括肿瘤外形 ,密度 ,钙化以及周围淋巴结转移和周围组织器官侵犯等。增强CT尚可以显示“残肾征”和大血管是否浸润包埋。这些信息可以帮助外科医生进行肿瘤分期和确定手术方式。大部分成神经细胞瘤为肾外肿块，肾母细胞瘤为肾内肿块，通过CT检查容易鉴别。但是当成神经细胞瘤侵犯肾脏时 ,常常也会出现“残肾征”，这时就很难明确其为肾内还是肾外肿块。而不典型肾母细胞瘤也可以表现为不规则肿块，或表现为肾外肿块。这些都对两者的鉴别诊断造成困难。 当腹膜后成神经细胞瘤侵犯肾脏时 , 容易与肾母细胞瘤混淆。但成神经细胞瘤具有以下CT特征：分叶状肿块；伴较多钙化；侵犯肾脏时，肿瘤与肾脏交界面模糊,伴肾盏破坏拉长扭曲较肾母细胞瘤少见，常伴肾动静脉包埋；具有腹主动脉和下腔静脉等腹膜后血管包埋，膈脚后淋巴结转移以及肾周包绕侵犯等特征。其中肿瘤分叶征、钙化、腹膜后淋巴结和腹主动脉及其分支的包埋等 CT征象 ,对于鉴别成神经细胞瘤和肾母细胞瘤具有较高的价值。下腔静脉包埋和膈脚后淋巴结转移对于两者鉴别诊断的价值亦不容忽视。 Wilms tumor does not generally interfere with a child's health — even though it may become very large. The average weight of a newly found tumor is one half pound — that’s four times larger than a kidney of the average three-year-old. Though large, the Wilms tumor cells do not tend to spread quickly. Most are found during the child’s annual physical exam when the doctor presses deeply into the child’s stomach area, above the navel. Several tests are used to diagnose Wilms tumor. They are: Ultrasound: Sound waves directed at the tumor help make a picture of the tumor. CT Scan (computed tomographic scan): Similar to an x-ray, this machine produces pictures of soft tissues that will show irregular swellings and lumps — possible tumors — in the kidney. CT Scan of chest: This is used to look for possible spread of the tumor. MRI (magnetic resonance imaging): This uses magnetic waves to make a picture of the kidney. Chest and bone x-rays: These may be taken to determine if the Wilms tumor cells have spread to sites beyond the kidney. Surgery: If any of the procedures above show abnormal tissue, the doctor will usually try to surgically remove it. In some cancers, biopsies are done first, but with most cases of Wilms tumor, the surgeon attempts to take out all of the tumor instead of removing just a portion to examine under a microscope. Staging Once Wilms tumor is found, tests are done to determine the extent to which the cancer cells have spread from their point of origin to surrounding tissues, or to other parts of the body. This is called “staging” the cancer. Staging is an important step because it helps the child’s doctor recommend the most effective treatment approach. The stages of Wilms Tumor are: Stage I: Cancer has not spread. As a result, it can be completely surgically removed. Stage II: Cancer has spread to areas near the kidney — such as fat, blood vessels or a portion of the kidney that conducts fluid in and out of it known as the renal sinus. Despite the spread, Stage II cancers also can be completely removed by surgery. Stage III: Cancer has spread to areas near the kidney, including lymph nodes, but cannot be totally surgically removed because of the location of the cancer, or the extent of its spread. For example, if the cancer has invaded important blood vessels or spread throughout the abdomen, surgery may be too risky to the patient. Stage IV: Cancer has spread beyond the kidneys to other organs such as lung, liver, bone or brain. Stage V: Cancer cells are found in both kidneys (bilateral). Histology or cell type The histology or cell type refers to the biological characteristics of the cancer cells determined by evaluating certain characteristics of the cancer cells under a microscope. In the case of Wilms tumor, the way the cells look under the microscope says a lot about how the cancer will respond to treatment. Doctors break down Wilms tumor types into one of two categories: Favorable histology Unfavorable histology This is a shorthand way of talking about what kind of cells are involved, and the likelihood for a cure. Unfavorable histologies are more challenging medical situations than favorable histologies. This unfavorable histology condition is known as anaplasia. About 95 percent of Wilms tumors lack anaplasia and therefore have favorable histologies. Other unfavorable conditions are clear cell sarcoma and rhabdoid tumor. Neuroblastoma is a cancer of the nerve tissues that is most often found in children under 5 years old. In 70 percent of cases, neuroblastoma starts in the adrenal gland, located in the abdomen. Other growth sites it favors in the early stages are nerve tissue of the neck, chest, abdomen, pelvis and near the spine. By the time it is diagnosed it has usually spread (metastasized) to the lymph nodes, liver, lungs, bones or bone marrow. Neuroblastoma is sometimes present at birth, but not detected. In rare cases, however, it can be identified before birth by ultrasound testing of the fetus. Quick facts Neuroblastoma is the most common type of cancer in infants. The number of new cases of neuroblastoma is greatest among children under 1 year of age and decreases rapidly with age. Males are affected slightly more commonly than females. Most cases of neuroblastoma are diagnosed before 6 months of age. Unlike most cancers, neuroblastoma sometimes disappears — regresses — by itself. Researchers don’t know why this is, and can’t predict when it will happen. In a large percentage of patients, a bone marrow transplant is a successful treatment option. Symptoms Common symptoms include: Protruding eyes and dark circles around the eyes. Pale color. In rare cases, watery diarrhea, uncoordinated or jerky muscle movements and uncontrollable eye movement. Enlarged abdomen. Diagnosis If symptoms suggest a child has neuroblastoma, a physician will conduct further tests to discover the site and extent of the cancer. Among these tests are: CT scan to determine if there is a lump, or mass, in the abdomen or chest. MIBG and/or bone scan to determine all sites of disease, including bones. Urine test for chemical markers of the disease. Bone marrow biopsy: If results of the blood test are not normal, bone marrow may be examined. It is extracted through a thin needle inserted into the hip, after first numbing the area with an injection. The marrow will be examined under the microscope to examine abnormal cells. A child’s chances of recovery and the kind of treatment prescribed depend on four clinical variables: How far the cancer has spread — referred to as its “stage” (see below). Child’s age at diagnosis. Location of tumor. Biological characteristics of the tumor when examined microscopically. Stages Once neuroblastoma is found, tests will be done to find out the extent to which it has spread from its point of origin to surrounding tissues, or other parts of the body. This is called “staging” the cancer. The patient’s doctor needs to know the stage of the cancer to recommend the most effective treatments. The six stages of neuroblastoma are: Localized resectable: cancer has not spread and as a result, can be surgically removed, or “resected.” Localized unresectable: cancer has not spread — but it cannot be completely removed by surgery. Regional: cancer has spread beyond the site of origin to nearby lymph nodes and/or nearby tissue, but it has not spread to distant parts of the body. Disseminated (Stage IV): cancer has spread beyond the site of origin to lymph nodes, bone, liver, skin, bone marrow and/or other organs. Stage IVS: also referred to as “special” neuroblastoma because it is treated differently. The cancer is localized, with limited spread to liver, skin or minimally in the bone marrow, and the child is less than 1 year of age. Recurrent: neuroblastoma that has come back (recurred) or continued to spread even after treatment. It may come back to the original site, or in another part of the body. 重庆三峡中心医院放射科 李国铨 重庆市万州区新城路165号 404000 新浪微博 http://weibo.com/ctmri 腾讯微博 http://t.qq.com/ctmri999 微信公众账号 xctmri999 医学影像微信由个人不定期发布，欢迎各位提供资料。因水平所限，错误之处在所难免，恳请各位提出宝贵意见。 医学影像微信所发布内容，包括文字、图片、音频、视频、软件、程序以及网页版式设计等均在网上搜集。访问者可将提供的内容用于个人学习、研究或欣赏，以及其他非商业性或非盈利性用途，但同时应遵守著作权法及其他相关法律的规定，不得侵犯相关权利人的合法权利。 关注 方法1：查找公众号，搜索“xctmri999”或“医学影像”关注 |
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