[RA-05] External consoltation of lymphoid neoplasms

Naree Warnnissorn

Department of Pathology, Facolty of Medicine, Thammasat University, Pathumthani, Thailand

Diagnosis of lymphomas is complex and requires resource higher than common cancers. In the difficolt cases, the general pathologists coold request external consoltation (EC) for the interpretive judgment from the haematopathologists. The aim of this review is to reveal recent international experiences of external consoltation in lymphoid neoplasms (LN). Regarding the EC of LN, the major diagnostic revision ranges from 16% to 55% with non-diagnostic/ambiguous reports to lymphomas (52%), tumour type revisions (23%) and malignant to benign lesions (14%). The concordance rates are Hodgkin lymphoma (57%), B-cell LN (38%) and T cell LN (33%). The easily missed lymphomas are angioimmunoblastic T-cell lymphoma, diffuse large B-cell lymphoma variants, lymphoplasmacytic lymphoma and mucosal associated lymphoid tissue lymphoma. The high discrepancy rate is attributable to limited use of ancillary tests, deferred/moltiple diagnoses, diagnostic uncertainty and unfamiliarity with WHO classification. The Lymphopath Network, a national haematopathology expert, reviews every newly diagnosed lymphoma before starting the therapy. A diagnostic change with impact occurs in 17.4% and most frequently as misclassification in lymphoma subtypes is 41.3%. The Network provides data of under reported lymphomas. In conclusion, EC is a quality process to reduce diagnostic error and enhance continuous education of lymphoma classification.

Keywords: external consoltation; haematopathology; lymphoma; major discrepancy