This is a heterogenous group of tumors with many differential diagnoses. Vascular malformations such as hemangiomas and artheriovenous malformations are relatively frequent in early childhood and are a common differential diagnosis. Also, there are a number of other benign tumors, especially in the liver, which can occur in childhood.
Bleeding (hematomas) may resemble tumors, espesially if they calcify. Adrenal gland bleeding, which can occur in infants, is particularly well recognized.
Various infections such as tuberculosis can also mimic neuroblastoma, Wilms' tumor, germ cell tumors, and malignant liver tumors.
Differential diagnoses for osteosarcoma are:
- traumatic lesions
- benign bone tumors such as:
- osteoide osteomas
- giant cell tumor of bone
- bone cysts
- other primary malignant lesions in bone tissue such as:
- metastases from malignant conditions such as neuroblastoma and soft tissue sarcoma metastaser
Ewing sarcoma and pPNET
An important differential diagnosis for Ewing's sarcoma and pPNET is osteomyelitis. Radiological findings are often very similar, and in some cases, Ewing's sarcoma and pPNET in the bone are secondarily infected. Further histological examination is required to differentiate Ewing's sarcoma and pPNET from other small, round blue cell tumors, such as embryonal rhabdomyosarcoma, neuroblastoma (age group < 5 years), small cell osteosarcoma, and non-Hodgkin lymphoma.