Background/Aim:Diagnosis of Hirschsprung's disease (HD) can be hard and requires good experience, principally for pathologists who infrequently encounter the disease. However, diagnosis is not always possible with hematoxylin and eosin (H and E) because staining has limitations in the identification of immature ganglion cells in neonates and the submucosal area.Aim:To assess the diagnostic role of calretinin immunostaining in HD in comparison to neuron-specific enolase.Patients and Methods:Formalin-fixed paraffin tissue blocks of full-thickness distal colonic and rectal biopsies for 48 patients who clinically presented with symptoms suspicious for HD were collected for the period from December 2012 to January 2016. All biopsies were already studied by routine H and E histopathological examination for the presence or absence of ganglion cells. Further confirmation of ganglion cells and nerve fibers was performed by immunohistochemical study for neuron-specific enolase and calretinin, respectively, in a private pathology laboratory.Results:According to the histopathological assessment, cases with absent ganglionic cells were considered to be HD, which comprised 40 cases out of the total 48 cases. The mean age for HD cases was 19.43 months. The male-to-female ratio in HD cases was 2.34:1. All HD cases showed negative expression of calretinin in small nerve fibers of the lamina propria, musularis mucosae, and submucosa, and negative expression of neuron-specific enolase in ganglionic cells. The sensitivity, specificity, positive predictive value, and negative predictive values for both the markers in the confirmation of diagnosis of HD were all 100%.Conclusion:Calretinin immunostaining, similar to that of neuron-specific enolase, is a highly sensitive and specific diagnostic aid to histopathological examination in suspected HD.

Background and Objective: Determination of HER2 gene is crucial in breast carcinoma management and prognosis, as HER2 alterations are linked to a shorter disease-free period, overall survival and resistance to tamoxifen anti-estrogen therapy and other chemotherapy regimens, regardless of the nodal or hormone receptor status. This study aimed to estimate HER2 gene status of infiltrative mammary cancer cases with immunohistochemically equivocal (2+) score using Silver DNA in Situ Hybridization (SISH) technique and to investigate its association with clinicopathological variables. Methods: The study included 52 formalin-fixed paraffin embedded tissue blocks from female patients with invasive breast carcinoma with score of 2+ (equivocal) HER2 immunohistochemistry. All cases were studied by silver DNA in situ hybridization technique (SISH) for the determination of the amplified HER2 DNA. Results: The SISH technique showed that HER2 gene was not amplified in 33 cases out of 52 (63.5%); while the rest of 19 cases (36.5%) revealed amplified gene status. According to age, HER2 gene status reported non-significant difference in the age groups between cases with amplified and non-amplified gene status ( P =0.173). There was a significant negative association between positive Estrogen (ER) and Progesterone (PR) status and HER2 gene amplification ( P = 0.002 and 0.017, respectively). Conclusion: More than half of breast carcinoma cases with equivocal HER2 immunoreactivity showed non-amplified gene status; this needs to be considered by oncologists in their management planning of breast cancer. Amplified HER2 gene is significantly associated with negative ER and PR status that affects patients’ management protocols and future outcome of the disease.