Calretinin immunohistochemical staining in Hirschsprung’s disease: An institutional experience

Abstract

OBJECTIVE: This study aims to evaluate the results obtained by calretinin staining on tissue samples for diagnosing\rHirschsprung’s disease (HD) in a single institution, by single expert.\rMETHODS: A retrospective evaluation was done for calretinin immunostaining in HD patients for a period of 3 years.\rCalretinin staining was evaluated in nerve fibers. Calretinin immunohistochemistry was considered positive if any staining\rwas seen in nerve fibers and/or ganglion cells in the lamina propria, muscularis mucosa or submucosa. According to\rstaining intensity, staining was classified as strong, weak or negative. The pathological diagnosis was based on presence\ror absence of ganglion cells (G0/G1) and nerve hypertrophy (N0/N1). Samples were classified according to the depth\r(presence of submucosa or intermuscular area), the type (biopsy or resection specimen) and staining intensity of calretinin (strong, weak, or negative staining).\rRESULTS: A total of 96 tissue samples from 56 patients were studied. Tissues were from colon (43.8%), rectum (43.8%),\rstoma (6.2%), ileum (3.1%) and appendix (3.1%). The pathological diagnosis was G0N0 in 14.6%, G1N0 in 54.2%, G0N1 in\r25% and G1N1 in 6.2% of cases. Our materials consisted of 92 tissue biopsies and four resection specimens. Intermuscular\rlayer was present in 87.5% of materials and 12.5% of biopsies contained submucosa. Calretinin staining was negative (C0)\rin 37.5% of cases, strong positive (C1) in 47.9%, and weak positive (C2) in 14.6%. When the C0 category was taken as the\rreference, the status of calretinin staining as C2 (weak positive) in cases with pathological diagnosis of G1N0 was found to be\r37.575 times that of cases with G0N0 (OR [95% CI]: 37.575 [2.928, 482.176], p=0.006) and the status of calretinin staining\ras C1 (strong positive) in cases with pathologic diagnosis of G1N0 was found to be 131.401 times that of G0N0 (OR [95%\rCI]: 131.401 [9.263, 1864.082), p<0.001).\rCONCLUSION: Calretinin staining is positive whenever ganglion cells are present independent from presence of nerve\rhypertrophy, the depth and the site of the biopsy or staining intensity. It is negative in all aganglionic samples. Calretinin\rstaining is a reliable ancillary test in HD diagnosis.