HHE Haematology supplement 2018 - Page 8

The incidence of neuroblastoma is 10.2 cases per million children under 15 years of age, and it is the most common cancer diagnosed during the first year of life identifiable neuropil or rosettes. Tumour cells are small in size and have no discernible cytoplasm. The nuclei are round, have a salt-and-pepper appearance and may contain distinct nucleoli. In these undifferentiated tumours, immunohistochemistry shows a pattern compatible with a presumed immature ganglionic (neuronal) SNS lineage origin. These observations suggest that undifferentiated NB tumours may be locked at an early neuronal differentiation stage, without the capacity to differentiate in response to the factors driving normal sympathetic neuronal differentiation. GNB show well-defined microscopic foci of differentiating neuroblastic cells distributed in a ganglio-neuromatous tissue background. The neuroblastic component of GNB tumours expresses markers reflecting an advanced ganglionic (neuronal) development. GN are composed predominantly of mature Schwannian stroma and ganglion cells usually surrounded by satellite cells. Mature Schwann cells represent the dominant component of the tumour, characteristically forming multiple fascicles covered with perineurial cells. GN infrequently display neuroendocrine features and usually occurs after the age of four years. Both features suggest that it arises from mature neuronal sympathetic ganglia or adrenal medulla neuronal cells. 1,2 The incidence of neuroblastoma is 10.2 cases per million children under 15 years of age, and it is the most common cancer diagnosed during the first year of life. 3,4 Neuroblastoma is usually diagnosed in very young children; the median age at diagnosis is 17 months. 5 The clinical 8 HHE 2018 | hospitalhealthcare.com presentation is highly variable, ranging from a mass that causes no symptoms to a primary tumour that causes critical illness as a result of local invasion, widely disseminated disease, or both. Usually the so-called primary tumour arises in the adrenal gland or paravertebral sympathetic ganglia. Two-thirds of neuroblastoma tumours have distant metastases in the bone, bone marrow, lymph nodes, liver or subcutaneous tissue upon diagnos 2vW&V2Vr"6VG&W'fW277FVWF7F62&RWG&VVǒ&&RPRF&BbWW&&7F&W6VB26Ɨ6V@vF"vFWBffVVBb&VvǖFW2FW6RGVW'2FBF7FǒWF7F66R`FW&R&RFffW&VBv2F7G&FgWW&&7FWFVW72fW7FvF'0w&VRFBvR&W6V6R"'6V6RbF7F@WF7F62BՔ4Ɩf6F&RWf7F'2fG2VFW"F2bvRv0fR&WGFW"&v626&VBvFFW 6G&VBǒ&V6W6RWW&&7F&W6V@VrfG2&Rg&WVVFǒ6Ɨ6VB'W@6FRWF7FF27V&w&W'6G&7BWF7FF266W2Fv6VB&WB6V'2`vRBFW66VG2fR&RFV@6W'6RFBWfVGVǒv7Bv2&RfFFVG2vFr&6WW&&7FfRfW'vB&v62vFffRזV"fW&7W'ff2b( 3RG&VFVBvF֖"FW&BRvWfW"FVG2FW"FF2vFWF7F6W2B"FVG2b琦vRvFՔ4ƖfVBGVW'2&R66FW&V@"BFV"WF6R27F"FW7FPFV6fRVFFFW&vFffRזV"0SRR&FVǒCRbWW&&7FFVG2&R676fVB2"B&FVǐbbFVFB&W7BFf'7BƖRFW&"&V6RGW&rFRf'7BGvV'2bG&VFVBFRG&FFVFFFW&WWF0&6f""WW&&7F6VFW06VFW&7W&v6W66bFR&'GVW"B&FFW&FW6RFƗFW2&P7Bg&WVVFǒ&RFG&7F6ǒ&VGV6RFPGVW"'W&FVFRGV7F@66ƖFF6W2B6VBF&V@6WFR&V֗76bFRF6V6R&VfW'&VB0֖&W6GVF6V6R$B7B6W&FfPw&W2vVBFV6VFRvF6P6VFW&vFWFvW2VWF07FV6V&W67VR266ƖFFf" WW&&7FFVG2"WW&&7FFVG2G&VFVBvFF266VB7FF&@66VfRSR&V7W'&V6R&FRv6F6FW2FB7BFW&WWF2fW&W2vF067W"GW&rFR7FvRb$BpgFW"f&&RW&BbVW66VB7FǐVFWFV7F&RF6V6RFVG2&V6RW7VǒvFWF7FF2f6&W67FBF7FF0FW&W2BWfVGVǒVFW&v&B@fW'vV֖r&w&W76FW2FR G&v&6b7W'&VBFW&W22FRvVV@bFRƖ֗FVBV&W"b6V2FBW66PGV7FB66ƖFFFW&W2FW6P6V2&R&RFVFW&v&ƖfW&FB ֖w&Fvfr&6RFFRWF7FF0&V7W'&V6RbWW&&7FFtC VFW&2&֗6rG&VFV@&FvF26GVFखVFW&FRVR77FV6&RFfFVBFF