Pediatric Hodgkin lymphoma in a South Indian regional cancer center: its immunomorphology, tumor-associated macrophages, and association with Epstein-Barr virus.

Pediatric Hodgkin lymphoma (HL) comprises approximately a fifth of all patients with HL in India. Seventy-four cases of pediatric classical Hodgkin Lymphoma (cHL) from a regional cancer center in southern India were analyzed on a tissue microarray (TMA) for the stage of B-cell differentiation of the Hodgkin/Reed Sternberg (HRS) cell by immunohistochemistry (IHC) using CD10, bcl6, MUM1/IRF4, and CD 138. Fifty-two of seventy-four (70.3%) cases were of late germinal center/early post-germinal center phenotype (CD10-/bcl6-/MUM1+/CD138-). Epstein-Barr virus (EBV) association using Epstein-Barr virus encoded RNA (EBER) RISH and EBV-LMP1 immunohistochemistry (IHC) revealed an EBV association of 93%. Tumor-associated macrophages (TAM) in the microenvironment were also assessed on the TMA by CD68 IHC, and most cases (59.7%) showed >25% TAMs, with no case showing ≤5%. These findings indicate that pediatric cHL in India is a tumor, predominantly, of late germinal center/early post-germinal center B cells, is almost invariably EBV associated, and with a high number of TAMs in the microenvironment. This latter finding suggests that criteria other than TAM scores need to be developed for risk stratification of pediatric EBV-associated HL especially in developing countries.

Accelerated phase of chediak higashi syndrome mimicking lymphoma--a case report.

SUMMARY: Chediak Higashi Syndrome (CHS) is a rare autosomal recessive disease, characterized by partial oculocutaneous albinism, frequent pyogenic infections, and the presence of abnormal large granules in leukocytes and other granule containing cells. The abnormal granules are readily seen in blood and marrow granulocytes. About 50% to 85% of patients eventually enter an accelerated phase, manifested by fever, lymphadenopathy, anemia, jaundice, neutropenia, thrombocytopenia, and widespread lymphohistiocytic organ infiltrates. The first accelerated phase of CHS may occur shortly after birth or several years later. Most patients undergo a variable period of recurrent infections before going into the accelerated phase. Therefore, primary presentation in the accelerated phase is unusual. This case was referred to our institution that is a tertiary care cancer centre, with a clinical diagnosis of lymphoma/leukemia. Hence this interesting case of CHS in accelerated phase at presentation is described. The child had 1-month history of fever, bilateral neck swellings, and loss of appetite. On the basis of the clinical presentation, hematologic, and histopathologic findings, a diagnosis of accelerated phase of CHS was made. The child was treated with antipyretics, antibiotics, and stem cell transplantation was suggested to him. When the child presents to a hospital with oculocutaneous albinism and recurrent infections, careful examination of the peripheral blood smear by an experienced morphologist cannot be overemphasized. A high degree of awareness and early recognition of the syndrome, could lead to the institution of the only possible curative treatment, bone marrow transplant, before the accelerated phase supervenes.

Gum hypertrophy - an unusual presenting feature in a case of precursor T-cell acute lymphoblastic leukemia.

Acute lymphoblastic leukemia/lymphoma, the malignant transformation of T-cell or B-cell precursors, is the most common diagnosis in pediatric oncology. Precursor T-cell acute lymphoblastic leukemia/lymphoma commonly affects adolescents, and is associated with mediastinal mass in over half of the cases, with early dissemination to bone marrow, gonads and the central nervous system. We present a rare case of precursor T-cell acute lymphoblastic leukemia/lymphoma with initial oral manifestation, presenting with the unusual features of gum hypertrophy and involvement of upper jaw and palate in a 10-year-old boy. This report discusses the clinical presentation, histopathologic and immunologic features, and diagnosis of this malignancy.

A novel Monoclonal Antibody against Notch1 Targets Leukemia-associated Mutant Notch1 and Depletes Therapy Resistant Cancer Stem Cells in Solid Tumors.

Higher Notch signaling is known to be associated with hematological and solid cancers. We developed a potential immunotherapeutic monoclonal antibody (MAb) specific for the Negative Regulatory Region of Notch1 (NRR). The MAb604.107 exhibited higher affinity for the "Gain-of-function" mutants of Notch1 NRR associated with T Acute lymphoblastic Leukemia (T-ALL). Modeling of the mutant NRR with 12 amino-acid insertion demonstrated "opening" resulting in exposure of the S2-cleavage site leading to activated Notch1 signaling. The MAb, at low concentrations (1-2 µg/ml), inhibited elevated ligand-independent Notch1 signaling of NRR mutants, augmented effect of Thapsigargin, an inhibitor of mutant Notch1, but had no effect on the wild-type Notch1. The antibody decreased proliferation of the primary T-ALL cells and depleted leukemia initiating CD34/CD44 high population. At relatively high concentrations, (10-20 µg/ml), the MAb affected Notch1 signaling in the breast and colon cancer cell lines. The Notch-high cells sorted from solid-tumor cell lines exhibited characteristics of cancer stem cells, which were inhibited by the MAb. The antibody also increased the sensitivity to Doxorubucinirubicin. Further, the MAb impeded the growth of xenografts from breast and colon cancer cells potentiated regression of the tumors along with Doxorubucin. Thus, this antibody is potential immunotherapeutic tool for different cancers.

Paediatric retinoblastoma in India: evidence from the National Cancer Registry Programme.

BACKGROUND: Globally, retinoblastoma is the most common primary intraocular malignancy occurring in children. This paper documents the recent incidence rates of retinoblastoma by age and sex groups from the Population Based Cancer Registries (PBCRs) of Bangalore, Mumbai, Chennai, Delhi and Kolkata using the data from the National Cancer Registry Programme. MATERIALS AND METHODS: Relative proportions, sex ratio, method of diagnosis, and incidence rates (crude and age standardized) for each PBCR and pooled rates of the five PBCRs were calculated for the years 2005/06 to 2009/10. Standard errors and 95% confidence limits of ASIRs by sex group in each PBCR were calculated using the Poisson distribution. Standardised rate ratios of ASIR by sex group and rate ratios at risk were also calculated. RESULTS: The maximum retinoblastoma cases were in the 0-4 age group, accounting for 78% (females) and 81% (males) of pooled cases from five PBCRs. The pooled crude incidence rate in the 0-14 age group was 3.5 and the pooled ASIR was 4.4 per million. The pooled ASIR in the 0-4, 5-9 and 10-14 age group were 9.6, 2.0 and 0.1 respectively. The M/F ratio in Chennai (1.9) and Bangalore PBCRs (2.0) was much higher than the other PBCRs. Among the PBCRs, the highest incidence rate in 0-4 age group was found in males in Chennai (21.7 per million), and females in Kolkata (18.9 per million). There was a distinct variation in incidence rates in the PBCRs in different geographic regions of India.

Bilateral nephromegaly simulating wilms tumor: a rare initial manifestation of acute lymphoblastic leukemia.

A 7-year-old boy was referred with a provisional diagnosis of bilateral Wilms tumor. Peripheral smear revealed elevated leukocyte count with 90% blasts. Bone marrow aspiration and biopsy were hypercellular with sheets of blasts. Immunohistochemistry on paraffin sections showed a pre-B phenotype of acute lymphoblastic leukemia. Computerized tomographic scan of the abdomen showed moderate bilateral renal enlargement. Ultrasound-guided fine needle aspiration cytology of both kidneys showed blasts similar to those seen in the bone marrow. Finally, a diagnosis of pre-B acute lymphoblastic leukemia infiltrating both the kidneys was made. This case is being presented because of its rarity.