Kapur Raj P, Raess Philipp W, Hwang Samuel, Winter Conrad
1 Department of Pathology, University of Washington and Seattle Children's Hospital, Seattle, Washington, USA.
2 Department of Pathology, Oregon Health & Science University, Portland, Oregon, USA.
Pediatr Dev Pathol. 2017 Jul-Aug;20(4):308-320. doi: 10.1177/1093526617697060. Epub 2017 Mar 23.
Acetylcholinesterase enzymatic histochemistry (AChE EHC), which highlights abnormal cholinergic nerves in the mucosa of aganglionic bowel, has been used for decades to evaluate rectal biopsies for Hirschsprung disease (HSCR). While useful diagnostically, AChE EHC is not compatible with conventional formalin-fixed and paraffin-embedded (FFPE) tissues and is not widely available. The choline transporter (ChT) is a putative alternative marker of cholinergic nerves. ChT immunohistochemistry (IHC) was investigated using FFPE biopsies and resections from patients with confirmed HSCR, as well as appropriate non-HSCR controls. ChT immunostaining was effective at identifying cases with HSCR and qualitatively similar to AChE EHC on frozen section. Among 3 pathologists, the diagnostic positive and negative predictive values based on ChT IHC ranged from 0.84-0.94 and 0.85-0.89, respectively, with good inter-observer agreement (Cohen kappa = 0.70-0.90). ChT IHC was useful in unusual scenarios in which calretinin (CR) IHC failed to correctly identify patients with HSCR. In 10 cases of short-segment HSCR, abnormal ChT+ mucosal innervation was present through the entire aganglionic segment and into portions of the TZ with submucosal nerve hypertrophy. In contrast, mucosal CR IHC was retained in the TZ and adjacent aganglionic bowel, which could lead to misinterpretation of a biopsy as ganglionic bowel. Indeed, 6 such patients were identified with paradoxical CR-positive mucosal innervation in their diagnostic biopsies. ChT IHC was interpreted as unequivocal HSCR in these cases, and HSCR was confirmed on resection. In summary, ChT IHC in FFPE tissue demonstrates high positive and negative predictive values for HSCR, is superior to CR IHC in a subset of cases, and can be incorporated into routine practice without the need for specialized techniques.
乙酰胆碱酯酶酶组织化学（AChE EHC）可突出显示无神经节肠段黏膜中的异常胆碱能神经，几十年来一直用于评估先天性巨结肠（HSCR）的直肠活检。虽然在诊断上很有用，但AChE EHC与传统的福尔马林固定石蜡包埋（FFPE）组织不兼容，且应用并不广泛。胆碱转运体（ChT）是胆碱能神经的一种潜在替代标志物。本研究使用确诊HSCR患者的FFPE活检组织和切除标本以及合适的非HSCR对照，对ChT免疫组织化学（IHC）进行了研究。ChT免疫染色在识别HSCR病例方面有效，在冰冻切片上与AChE EHC在定性上相似。在3名病理学家中，基于ChT IHC的诊断阳性和阴性预测值分别为0.84 - 0.94和0.85 - 0.89，观察者间一致性良好（Cohen κ = 0.70 - 0.90）。在钙视网膜蛋白（CR）IHC未能正确识别HSCR患者的特殊情况下，ChT IHC很有用。在10例短段型HSCR中，整个无神经节段及部分黏膜下神经肥大的过渡带（TZ）均存在异常的ChT + 黏膜神经支配。相比之下，黏膜CR IHC在TZ和相邻的无神经节肠段中保留，这可能导致将活检误判为有神经节肠段。实际上，在这些患者的诊断活检中，有6例被发现存在矛盾的CR阳性黏膜神经支配。在这些病例中，ChT IHC被解释为明确的HSCR，切除术后证实为HSCR。总之，FFPE组织中的ChT IHC对HSCR显示出较高的阳性和阴性预测值，在一部分病例中优于CR IHC，并且无需特殊技术即可纳入常规实践。
