<unk>  is the most common solid extracranial cancer in childhood and is the most common cancer in infancy. It is a malignant tumor that arises from neural crest cells, which are normally involved in the development of the sympathetic nervous system and adrenal glands. It is usually located along the sympathetic nervous system structures including; adrenal glands, retroperitoneal organs, paravertebral sympathetic chain, organ of zuckerkandl and posterior mediastinum. It was first described by Rudolf Virchow in 1864 as an abdominal tumor in a child as "glioma". James Homer Wright in 1910, described circular clumps of bone marrow (now named Homer-Wright pseudorosettes) and advanced the understanding that tumor originated from primitive neural cells and could metastasize to bone. International<unk>  pathology classification system is used for the classification of<unk>  tumors, which divides it into 02 main categories based on morphologic features of<unk>  tumors into: schwannian stroma poor and schwannian stroma rich/dominant.<unk>  tumor cells secrete catecholamine by products including vanillylmandelic acid (VMA) and homovanillic acid (HVA) and vasoactive intestinal polypeptide (VIP) hormone as well. The various genes involved in pathogenesis of<unk>  include;<unk> PF10, KIF1B, ALK, LMO1 and PHOX2A genes. The most common genetic mutation is gain of chromosome 17q and MYCN oncogene amplification predicts more aggressive<unk> .<unk>  can also be associated with a number of syndromes including; neurofibromatosis type 1, beckwith-weidemann syndrome and hirschsprung disease. On gross pathology, the characteristic finding of<unk>  is a well defined, bulky and tan colored mass, that can be associated with fibrous pseudocapsule, necrosis or hemorrhage. On microscopic picture, the presence of round blue cells separated by thin fibrous septa are a characteristic finding. There are no known established causes for<unk> . The risk factors for<unk> s diagnosed during infancy include; maternal anemia during pregnancy, neonatal respiratory distress syndrome and low 1 minute Apgar score. However, the risk factors for<unk>  cases diagnosed at age 1 year or above is not known. The overall incidence is 4.9 per 1,000,000 individuals in united states. Males are slightly more affected than females with 1.2:1 ratio.<unk>  usually affects individuals of the caucasian race. Intra-abdominal<unk>  must be differentiated from other diseases that cause abdominal distension and constipation such as Wilms tumor and ganglioneuroma. Intra-thoracic<unk>  must be differentiated from other diseases that cause shortness of breath and chronic cough such as intrathoracic lymphoma and extra lobar pulmonary sequestration. There are no routine screening tests for<unk>  due to lack of any mortality benefits.<unk>  may progress to develop fatigue, loss of appetite, joint pain and fever if left untreated. There is gradual development of site specific symptoms as the tumor size gradually increases. Complications of<unk>  include; persistent refractory diarrhea, horner's syndrome, hypertension, transverse myelopathy, anemia and suppressed immunity. The prognosis of<unk>  is generally regarded as poor, depending on the tumor extent at the time of diagnosis. The other prognostic factors for<unk>  include; patient's age, tumor stage and grade, genetic mutations and response to treatment. According to the conventional International<unk>  Staging System (INSS), there are 6 stages of<unk>  based on the tumor size, lymph node involvement, and presence of metastasis. However, according to a newly proposed International<unk>  Risk Group Staging System (INRGSS), there are four stages of<unk>  based on the extent of dissemination and image findings.<unk>  patients are risk stratified according to the Children Oncology Group (COG) risk stratification system into a low risk group, an intermediate risk group, and a high risk group based on the tumor INSS stage, the patient's age, tumor grade, and the amplification of MYCN gene. General<unk>  symptoms include; fever, irritability, fatigue, loss of appetite and weight loss. Other symptoms depending upon the anatomical location of<unk>  include; abdominal pain, distension and constipation (abdomen), shortness of breath, chronic cough & difficulty swallowing (posterior mediastinum), weakness, numbness, paralysis (retroperitoneum), visual defects, facial bruising (head & neck) and pallor, bone pain (bone marrow metastases). Physical examination findings of<unk>  include; fever, hypertension, tachycardia, pallor, ecchymoses, nystagmus, proptosis, ptosis, abdominal mass, brisk reflexes, sensory loss and ataxia. The laboratory findings in<unk>  include; ↓ hemoglobin, ↑ ferritin, ↑ catecholamine, ↑ dopamine, ↑ vanillylmandelic acid (VMA), ↑ homovanillic acid (HVA), ↑ lactate dehydrogenase and ↑ neuron-specific enolase levels. There are increased urinary catecholamine, vanillylmandelic acid (VMA) and homovanillic acid (HVA) levels. X ray findings of<unk>  include; intrathoracic or intraabdominal soft tissue mass, calcification, remodeling of surrounding ribs & vertebral bodies, thinning of surrounding pedicles and ill defined, metaphyseal, lucent bone lesions seen in metastases. CT scan of the neck, chest and abdomen is the gold standard test in<unk>  as it can localize the tumor and determine degree of involvement as well. CT scan in<unk>  can show the presence of; heterogeneous mass, calcification, necrosis, compression of surrounding vessels, invasion of psoas muscle & kidneys and swollen lymph nodes. MRI is considered the most useful modality in staging of<unk> . It is superior to CT scan when determining marrow infiltration and intra spinal tumor extension. The definitive diagnosis of nueroblastoma is confirmed by a biopsy. Children oncology group (COG) risk stratification system determines the protocol of management used for<unk>  patients. COG risk stratification system divides the patients into 03 groups: low risk, intermediate risk and high risk patients. Low risk<unk>  patients are usually managed by either observation or surgical resection of the tumor. Intermediate risk patients are managed by neoadjuvant therapy in advance of a definitive surgical resection. High risk<unk>  patients are usually managed by a combination of surgery, chemotherapy, radiation therapy, hematopoietic stem cell transplantation, immunotherapy and isotretinoin. Surgical intervention is curative as a single therapeutic modality for management of low risk<unk>  patients. In intermediate risk patients, surgical intervention must be followed by chemotherapy. However, the benefits of surgery to achieve complete tumor resection in high risk patients with metastatic disease is not clearly demonstrated.
Neuroblastoma
Germinoma
Neuroma
Paraganglioma
Craniopharyngioma
Myxoma
Ganglioglioma
Ameloblastoma