Research Abstracts

Kirsch R, Bokhary R, Marcon MA, Cutz E.

Division of Pathology, Department of Pediatric Laboratory Medicine, The Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada. rkirsch@mtsinai.on.ca

OBJECTIVES: To evaluate the utility of activated mucosal mast cells (MC) in the differential diagnosis of eosinophilic esophagitis (EE) and gastroesophageal reflux disease (GERD). METHODS: Intraepithelial eosinophils and MC were quantified in esophageal biopsies from 25 children with EE, 22 children with GERD and 22 controls. MCs were identified by immunohistochemistry for MC tryptase, whereas MC activation status was evaluated by immunohistochemistry for immunoglobulin E (IgE) and by electron microscopy. RESULTS: Esophageal biopsies from patients with EE showed higher intraepithelial eosinophil counts (55 +/- 27.5 vs 6.9 +/- 9.7, P < 0.0001) and MC counts (26.3 +/- 12.7 vs 7.8 +/- 8.9, P < 0.0001) than those from patients with GERD. Almost all EE biopsies (24 of 25 patients; 96%) contained IgE-bearing cells compared with 9 of 22 (41%) GERD biopsies (P < 0.001). GERD biopsies with intraepithelial eosinophil counts >7/high-power field (suggesting an allergic component) contained IgE-bearing cells in 6 of 7 (86%) cases compared to 3 of 15 (20%) cases with eosinophil counts <7/h.p.f (P < 0.01). No intraepithelial eosinophils, MC or IgE-positive cells were present in controls. Electron microscopy confirmed the presence of intraepithelial MC and changes in cytoplasmic granules indicative of MC and eosinophil activation. CONCLUSIONS: Intraepithelial MC counts and IgE-bearing cells may help to differentiate EE and GERD and to define a subset of GERD patients in which an allergic component is present. The findings support a role for a MC-mediated hypersensitivity reaction in the pathogenesis of EE.

PMID: 17204948 [PubMed - indexed for MEDLINE]

Mai KT, Bokhary R, Yazdi HM, Thomas J.

Department of Laboratory Medicine, The Ottawa Hospital, Ontario, Canada. ktmai@civich.ottawa.on.ca

Hybrid follicular carcinoma (FC) and papillary thyroid carcinoma (PTC) have not been previously well described. Consecutive cases of 29 FC, 12 Hurthle cell carcinomas (HC), 247 PTC and 13 Hurthle cell PTC (HPTC) were reviewed with special attention to the coarse (CC) and fine chromatin patterns (FIC), as well as to the presence of nuclear grooves, pseudoinclusions or optically clear appearance. Limited nuclear features of PTC (LNF-PTC) are defined as areas of tumor with FIC in addition to some other nuclear features, but insufficient for the diagnosis of PTC. Tumors with nuclei showing an admixture of CC and PTC or LNFPTC were submitted for immunostaining for cytokeratin 19, HBME and Ret/PTC. FC and HC contained areas of LNFPTC in 25 tumors and focal PTC in 3 tumors. None of these cases was associated with lymph node metastasis. Areas with CC were found in 54 PTC and 3 HPTC. The rates of vascular invasion and distant metastasis tended to be higher for PTC with areas of coarse chromatin pattern than for PTC without such areas; however, the difference was not statistically significant. Immunoreactivity for cytokeratin 19 and HBME was moderate to strong for PTC and focal areas of PTC or LNFPTC in FC without Hurthle cell changes. Ret/PTC immunostaining was positive in areas of LNFPTC or focal PTC in three FC. Focal PTC or areas of LNFPTC are frequently seen in FC. Likewise, areas of CC are often present in PTC. The presence of these focal areas does not appear to change the clinical behavior of the tumor and therefore does not warrant a change of nomenclature.

PMID: 12049333 [PubMed - indexed for MEDLINE]

Mai KT, Bokhary R, Yazdi HM, Thomas J, Commons AS.

Division of Anatomical Pathology, Department of Laboratory Medicine, The Ottawa Hospital-Civic Campus, Ontario, Canada. ktmai@ottawahospital.on.ca

BACKGROUND: We have recently observed that Hürthle cell tumours and papillary thyroid carcinoma with tumour cells showing decapitation of luminal portion of the cytoplasm (apocrine-like changes) display negative or decreased immunoreactivity for HBME. The purpose of this study is to correlate papillary thyroid carcinoma with positive and negative immunoreactivity for HBME with the histopathological features. METHODS AND RESULTS: Two hundred and five thyroid neoplasms including carcinoma and adenomas were grouped into Hürthle cell tumours, tumours with or without some features of Hürthle cells, tumours with apocrine-like changes and adenomas with or without limited nuclear features of papillary thyroid carcinoma but not diagnostic for papillary thyroid carcinoma. All neoplasms were submitted for immunostaining with cytokeratin 19 (CK19) and HBME. Papillary thyroid carcinoma, follicular carcinoma and follicular adenoma that have areas of limited nuclear features but not diagnostic for papillary thyroid carcinoma showed stronger immunostaining for HBME than their respective counterparts with Hürthle cell changes. All Hürthle cell tumours showed negative to focal reactivity. This decrease of reactivity for HBME was proportional to the levels of Hürthle cell changes. In addition, focal to extensive apocrine-like changes were seen in most Hürthle cell neoplasms and rarely seen in non-Hürthle cell neoplasms. Apocrine-like changes abolished or decreased HBME immunoreactivity of papillary thyroid carcinoma and tumours with limited nuclear features. Immunostaining for cytokeratin AE3 was not affected by Hürthle cell or apocrine-like changes. CONCLUSIONS: All papillary thyroid carcinomas without Hürthle cell or apocrine-like differentiation are reactive for HBME. Hürthle cell tumours and tumours with Hürthle cell or apocrine-like changes show negative or focal reactivity for HBME. Except for this limitation, HBME is a sensitive marker for papillary thyroid carcinoma and tumours with limited nuclear features.

PMID: 11952857 [PubMed - indexed for MEDLINE]