This study aims to answer the question whether the World Health Organization (WHO) classification of non-Hodgkin's lymphoma (NHL) can be practised to international standards at the Lymphoma Registry (LR) established at the Tata Memorial Hospital, Mumbai, India. Furthermore, the study aims to identify differences in the distribution of NHL subtypes at this LR (likely to be representative of India) as compared to the rest of the world. A panel of 5 expert hematopathologists from the NHL Classification Project reviewed 200 consecutive NHL cases at the LR in January of 2001. These cases were accrued during August and September, 2000. On all cases, hematoxylin and eosin stains and appropriate immunostains were available for review. The diagnosis made by the host pathologist at the LR (KNN) and the initial diagnosis made by each of the expert hematopathologists was compared with the consensus diagnosis. A consensus diagnosis was made by the 5 experts in 197 cases. The agreement of the host pathologist with the consensus diagnosis was 82% and the agreement of the individual experts with the consensus diagnosis varied from 76-88% (mean 82%). According to the consensus diagnosis, 80% of NHLs were of B-cell type, 18% were of T-cell type, and the immunophenotype could not be determined in the remaining 2% of cases. In conclusion, the WHO classification of NHL was properly utilized at the Lymphoma Registry, Mumbai, India, and geographic differences were noted in the distribution of NHL subtypes at the LR as compared to the rest of the world. Precursor T lymphoblastic leukemia/lymphoma was more common in India (7%) than the rest of the world (1-4%), and indolent B-cell NHLs (29%) were less common than in the West. As compared to China and Japan, peripheral T-cell lymphoma (4.6%), extranodal NK/T cell lymphoma, nasal type (0.5%) and extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-lymphoma) (2.6%) were less common, but follicular lymphoma (15%) and chronic lymphocytic leukemia/small lymphocytic lymphoma (5%) were more common. This suggests that the distribution of the B-cell and T-cell lymphomas in the Indian population, except for lymphoblastic lymphoma, lies in between the Western world (mainly Caucasian) and the Orientals.

Summary.We investigated the clinical significance and long-term follow-up of detecting minimal residual disease (MRD) in hairy cell leukaemia (HCL) in complete remission (CR) after treatment with deoxycoformycin (DCF). MRD was assessed in 23 patients by immunophenotyping peripheral blood and bone marrow frozen sections using a panel of antibodies, CD11c, CD25, CD103 and HC2, which detect hairy cells. 31 cases with active HCL were used as controls. 10/23 patients (43%) had MRD in bone marrow (seven), blood (one) or both sites (two) which was not detected on haematoxylin-eosin bone marrow sections nor by immunohistochemistry on paraffin sections in six cases tested. Sequential studies in four cases did not show changes in the amount of MRD. At a median follow-up of 72 months (range 15-108), 5/23 (22%) patients have relapsed with a median time of 59 months (range 15-105). MRD was detected in three of the five patients who relapsed. In the two patients with negative MRD, one relapsed with an abdominal mass and the other was a late relapse at 84 months. MRD was also documented in 7/18 patients who continued in clinical CR for a median of 80 months (range 63-98). There were no statistical differences in disease-free survival between MRD þ and MRD ¹ patients (P ¼ 0 . 8). Our findings indicate that relapse after long-term remission achieved with DCF cannot be predicted when MRD is detected by sensitive methods. A search for other parameters such as proliferative rate of the residual cells or chest and abdominal CT scan might identify patients with a higher probability of disease recurrence.

Presentation of Hodgkin's disease as an endobronchial lesion is rare. Four such cases are described and nine other previously reported cases are reviewed. The difficulties in diagnosis and management, when the disease presents in this manner, are discussed. This diagnosis must be considered when patients present with an endobronchial tumor because careful staging and treatment may lead to cure with the avoidance of major surgery. Cancer 53:147‐150, 1984.