NB84

NB84 is an antibody raised against an antigen from human neuroblastoma tissue. It recognises an uncharacterised 57 kD molecule. It works reliably on formalin-fixed paraffin embedded tissue.

NB84 appears to be more sensitive but less specific than synaptophysin for neuroblastic differentiation². Evaluation in decalcified bone trephines may be difficult due to diffuse intense background staining².

Immunohistochemical expression

Non-neoplastic tissues showing positivity include some epithelia (tonsillar, colonic, pneumocytes, hepatocytes, renal, prostatic, basal cells of squamous epithelium), cardiac and skeletal muscle, brain, adrenal cortex and placental trophoblast².

	Differentiated neuroblastoma	83/83 (all tumours were negative for CD99. The stroma-rich cases showed fine punctate positivity of schwannian and ganglioneuroma-lien areas while ganglion cells and neuropil were strongly positive.)2	17/19 (only 8/19 stained for neurofilament)1
	Undifferentiated neuroblastoma	21/22 (all tumours were negative for CD99. 15 were synaptophysin positive,. All were neurofilament negative.)2
	Ewing's sarcoma	9/14 (staining was weak and focal in most cases)1, 7/39 (2 of 16 skeletal and 5 of 23 extra-skeletal)2
	PNET	4/92, 1/1 (this case was negative for neurofilament)1
	Cerebellar medulloblastoma	3/182
	DSRCT	3/6 (the numbers of positive cells are often less than in neuroblastoma)2
	Alveolar rhabdomyosarcoma	0/162	0/121
	Embryonal rhabdomyosarcoma	0/262
	Wilm's tumour	1/14 (focal positivity in one case)2, 0/17 (some of the differentiated tubular structures stained weakly)1
	Lymphoblastic lymphoma / ALL	0/122, 0/31
	Small cell carcinoma of lung	0/102

NB84 was more sensitive but less specific than synaptophysin².

Diagnostic utility

• Diagnosis of neuroblastoma. It needs to be used in a panel to differentiated neuroblastoma from Ewing's sarcoma / PNET (CD99 positive) and DSRCT (cytokeratin and desmin positive).

References

¹Thomas, J. O., J. Nijjar, et al. (1991). "NB84: a new monoclonal antibody for the recognition of neuroblastoma in routinely processed material." J Pathol 163(1): 69-75.

²Miettinen, M., J. Chatten, et al. (1998). "Monoclonal antibody NB84 in the differential diagnosis of neuroblastoma and other small round cell tumors." Am J Surg Pathol 22(3): 327-32.

This page last revised 15.1.2004.

©SMUHT/PW Bishop