Systemic xanthogranuloma involving bone marrow and skin in a case of B-Lymphoblastic Leukemia.

Juvenile xanthogranuloma is a benign self-limiting lesion commonly described in infants and young children. It most commonly involves the skin presenting as single or multiple yellowish-brown papules. Clinical scenario with the classic histomorphology showing histiocytic aggregates in the dermis with xanthomatous cytoplasm, toutan type giant cells, immunohistochemistry with positive CD68, CD163, factor XIIIa and negative CD1a and S-100 help in diagnosis. However, diagnosis becomes challenging with predominant systemic bone marrow involvement in post-B-lymphoblastic leukemia settings.

Under the Microscope: A Case Report of Thoracic SMARCA4-Deficient Undifferentiated Tumor with Review of the Literature.

OBJECTIVE: SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a highly malignant neoplasm with an undifferentiated or rhabdoid phenotype, posing a diagnostic challenge. This case report aims to create awareness about this rare neoplasm while dealing with cases presenting with undifferentiated morphology. CASE REPORT: A 55-year-old gentleman with constitutional symptoms and lymphadenopathy. Imaging revealed a mass lesion in the right upper lobe of the lung. A biopsy of the cervical lymph node showed diffusely effaced architecture replaced by sheets of undifferentiated pleomorphic cells with vesicular nuclei, prominent nucleoli, eosinophilic cytoplasm, and multiple necrotic foci. An extensive immunohistochemistry (IHC) panel was applied, which showed positivity for synaptophysin, vimentin, and focal CD34 and EMA expression. Other markers like pan-cytokeratin, p40, TTF1, CD56, INSM1, calretinin, CD45, SOX10, S100, CD30, CD117, SMA, and Desmin were negative, with INI1 retained. The IHC panel excluded the morphological differentials of carcinoma, lymphoma, rhabdomyosarcoma, melanoma, and germ cell tumor. Further literature review led to the possibility of the SMARCA4-UT entity, which had a morphology and IHC profile similar to the present case. Testing for SMARCA4 (BRG-1) by IHC showed a complete loss in the tumor cells, favoring the diagnosis of Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). CONCLUSION: SMARCA4-UTs are rare, highly aggressive, and poorly differentiated thoracic tumors. Recognizing them is vital as there is potential for therapeutic interventions such as immunotherapy and SMARCA4-targeted therapies, offering promising prospects for the future.

Toxoplasmosis lymphadenopathy-A series of 8 cases diagnosed in a 2-year timeframe: Is it a needle in a haystack?

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, an obligate intracellular parasite. Clinical presentation of infection depends on the age and immune status of the patient. In immunocompetent patient, it may present as a non-specific lymphadenopathy and self- limiting illness. In contrast, in immunocompromised patients it can be a life-threatening infection. We present a series of 8 cases of toxoplasma lymphadenitis diagnosed in our institute in last two years. Lymphadenopathy raises a suspicion of malignancy; however, diagnosis of reactive lymphadenitis often marks the end of diagnostic evaluation. Careful morphological evaluation, the classic triad, often can direct at a conclusive diagnosis. We are presenting a case series to draw attention to this entity as majority of the published literature is in the form of case report and serological surveys and very occasional study showing both the histopathology and serology in tandem.

Frequency of Nucleophosmin 1 Expression by Immunohistochemistry in Acute Myeloid Leukemia.

Nucleophosmin (NPM1) mutation is one of the most common recurring genetic abnormalities seen in acute myeloid leukemia (AML). Immunohistochemistry serves as a cost effective and simple surrogate testing method for detection of NPM1 mutation. This study was conducted to evaluate the frequency of aberrant cytoplasmic nucleophosmin 1 expression in leukemic blast cells on formalin fixed bone marrow trephine biopsy (BMB) sections and also to correlate this data with the reference molecular method (reverse transcriptase-polymerase chain reaction; RT-PCR and gene sequencing), where available. Immunostains were performed using mouse anti-NPM1 monoclonal antibody on 71 paraffin embedded bone marrow biopsies (BMB) of patients with AML of any French-American-British (FAB) subtype. Results of immunohistochemistry (IHC) were then compared with the reference molecular method. The proportion of NPM1 expression by immunostaining in AML cases was found to be 17%. Twelve of the total 71 cases demonstrated cytoplasmic nucleophosmin (NPMc+) on immunostaining. Eleven of the positive cases that were correlated with the molecular standard demonstrated mutation in exon 12 of NPM1 gene. Cytoplasmic nucleophosmin expression by immunostaining was found to be in complete agreement with the standard molecular method. In a resource restricted setup, the information from this study might help in providing an inexpensive and accurate detection method to facilitate introduction of this marker in diagnostic and prognostic workup of AML especially in patients showing normal karyotype and no common recurrent translocations.

Plasmablastic Lymphoma: A Clinicopathological Study from a Tertiary Care Cancer Center in South India.

Background Plasmablastic lymphoma (PBL) is a rare aggressive B cell lymphoma that is commonly encountered in patients with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). In this case series, we describe the clinicopathological features of cases of PBL seen at a tertiary care center in South India. Materials and Methods Medical records of patients diagnosed with PBL between January 2009 and November 2017 were reviewed. PBL was defined as per the World Health Organization 2016 classification for hematopoietic and lymphoid neoplasms. The slides were reviewed with hematoxylin and eosin along with immunohistochemistry (IHC) including CD45, CD20, PAX5, CD79a, CD3, CD5, CD138, MUMI, EMA, ALK, and Ki67. Epstein-Barr virus (EBV) association was documented by rapid in situ hybridization (RISH) studies wherever possible. The demographic data, clinical presentation, treatment details, and outcomes are elaborated using descriptive statistics. Results During the study period, nine patients with PBL were identified. The median age at presentation was 47 years (range: 36-54 years). All patients had associated HIV/AIDS, eight (89%) had extranodal disease, and six (66%) had advanced clinical stage (stage III). All biopsies were positive for CD45, CD138, and MUM1, and negative for CD79a and T cell markers with a high Ki67 proliferation index (85-90%); CD20 was faint positive in one patient, and CD56 was positive in one (11%) patient. EBV-RISH was tested in two patients and was positive in one. Bone marrow was uninvolved in all the cases. At the time of last follow-up, three patients were alive. Treatment details were available in six patients. With frontline therapy, four patients achieved a complete remission (CR) and one patient developed progressive disease. Three of four patients in CR are alive till the last follow-up. Conclusion PBL is a rare form of lymphoma with predominant association with HIV, extranodal location, and characteristic IHC pattern.

Acute Myeloid Leukaemia with Gene Mutation: A Correlation with Haematological and Immunophenotypic Characteristics and Our Experience in a Tertiary Care Cancer Center in South India.

OBJECTIVE: Molecular genetic analysis of FLT3, NPM1, and CEBPA is already the standard of care in patients with acute myeloid leukaemia (AML) and represents the most frequent genetic alterations and important diagnostic and prognostic indicators. This study was undertaken to determine the frequency of FLT3 and NPM1 gene mutations in our institution and to characterize the association between gene mutations and haematological parameters as well as immunophenotypic features. MATERIAL AND METHOD: Morphological, haematological and immunophenotypic characteristics of NPM1 and FLT3 mutations in 126 patients of de novo AML including adults and children were studied. Apart from the French American British (FAB) method for classification, blasts were assessed for cuplike morphology as per strict definition for cuplike nuclei, ≥10% blasts with nuclear invaginations ≥25% of the nuclear area. RESULTS: FLT3 mutation in 31/126 (25%) and NPM1 mutation was found in 17/126 (13.4%) of the AML patients. 6 (5%) samples were positive for both NPM1 and FLT3/ITD mutations. Associations between the FLT3 and NPM1 gene mutations with haematological and immunophenotypic characteristics are reported. CONCLUSION: The results suggest that presence of distinct morphology and haematological and immunophenotypic characteristics together may serve as important indicators and surrogate for NPM1 and FLT3/ITD mutations. Further, comprehensive studies on the biological effects of NPM1 and FLT3/ITD mutations and their interactions with other genetic alterations are needed to gain insight into the molecular mechanism of these mutations involved in the pathogenesis of AML.

Multiplex Approach in Classification, Diagnosis, and Prognostication in Acute Myeloid Leukemia: An Experience from Tertiary Cancer Center in South India.

INTRODUCTION: Acute myeloid leukemia (AML) is a heterogeneous group of disorders classified as per FAB subtypes and more recently by WHO by underlying genetic abnormalities. AIMS AND OBJECTIVES: This study aims to analyze the morphology, immunophenotype, cytogenetic and molecular abnormalities in around 200 patients of AML diagnosed over a period of 7 years at our institute and to determine relative frequency of various subtypes (based on FAB and WHO classification). An attempt to characterize the associations between hematological parameters, immunophenotype and these subtypes was also made. MATERIALS AND METHODS: All cases diagnosed as AML on morphology, cytochemistry and/or immunophenotyping and tested for recurrent genetic abnormalities during period of Jan 2008-July 2014 were included in the study. RESULTS: Age of presentation was younger in our AML patients as compared to western literature. Amongst FAB and WHO subtypes, M2 and t (15;17) PML-RARA were the most common groups respectively. As expected, CD33, CD13, were the most commonly expressed markers followed by HLA-DR, CD117, CD34 and CD14. Aberrant expression was seen in 62(41.6%) cases, most common was CD7 (15.4%), followed by CD56 (14.8%), CD19 (6.7%) and CD2 (4.7%). Significant associations between immunophenotypic markers and FAB subtypes as well as WHO subtypes were established. CONCLUSION: This is a hospital based study, giving a detailed account of frequencies of AML subtypes, hematological parameters and immunophenotypic markers in AML patients at our institute. Being a large and one of its kind study to establish significant associations between various haematological and immunophenotypic parameters with respective AML subtypes and genetic abnormalities, it might prove to be very useful in Indian setup where facilities for cytogenetic analysis are not available in many laboratories.

A Case of AML-M2 with Sole Interstitial Deletion in 9q Without AML1-ETO/Inv 16 Rearrangement and FLT3/NPMI Mutations.

Conventional/molecular cytogenetics is important in identification of genomic abnormalities, for prognostication and in risk stratification of de novo patients with acute myeloid leukemias (AML). Here we present an AML M2 case showing the sole karyotypic abnormality, the rare interstitial deletion in the long arm of chromosome 9 with the loss of segment q12-q13.

A near tetraploid clone in acute myeloid leukemia with CD56 expression.

Acute myeloid leukemia (AML) is a heterogeneous disorder characterized by specific morphology, immunophenotype and genetic rearrangements. Multiple recurrent chromosomal aberrations have been identified by conventional cytogenetic analysis, which are now widely recognized as one of the most important diagnostic and prognostic determinants in AML. Here, we present a case with unusual cytogenetics, which has been described in very few patients.