OBJECTIVETo observe the expression and distribution of substance P (SP), neurofilament-H (NFH) in glomus tumors with chronic pain, and to discuss the process of chronic pain and the relationship with pain degree.

METHODSTwenty-seven patients diagnosed as glomus tumor with chronic pain were enrolled as case group, and divided into light pain symptomatic group (LPSG) (n = 12) and severe pain symptomatic group (SPSG) (n = 15) according to clinical manifestations. Control group (CG) were enrolled by 30 patients with amputated extremities or hands after trauma. Immunohistochemical methods were used to determine the expression of SP, NFH which were detected quantitatively by computer graph analysis system too.

RESULTSThe positive expression and distribution of SP, NFH existed in all the three groups and SPSG expression level was the highest [Grayscale Value(SP) (143.3 +/- 7.5), Grayscale Value(NFH) (167.7 +/- 4.4)], LPSG followed [Grayscale Value(SP) (156.2 +/- 8.2), Grayscale Value(NFH) (194.8 +/- 4.0)], control group was the third [Grayscale Value(SP) (208.2 +/- 16.6), Grayscale Value(NFH) (225.1 +/- 8.3)]; The difference of expression level among three groups was significant [SPSG vs LPSG (P(SP) = 0.002, P(NFH) < 0.0001), SPSG vs CG (P(SP) < 0.0001, P(NFH) < 0.0001), LPSG vs CG (P(SP) < 0.0001, P(NFH) < 0.0001)]. The findings of Pearson product-moment correlation analysis between quantitative grayscale value of SP, NFH respectively and pain score in all the patients with glomus tumor showed linear negative correlation (r(SP) = -0.8974, P(SP) = 0.000001; r(NFH) = -0.6545, P(NFH) = 0.000212).

CONCLUSIONSP is the mainly afferent pain transmitter in the process of chronic pain in glomus tumor, and NFH plays an important role in pain-transmitted activities.