Guldeep Uppal

The Utility of BRAF V600E Mutation-Specific Antibody VE1 for the Diagnosis of Hairy Cell Leukemia

OBJECTIVES BRAF V600E mutation is characteristic of hairy cell leukemia (HCL). A V600E mutation-specific antibody, VE1, has been recently developed. We studied the diagnostic utility of this antibody in HCL and compared it with other B-cell neoplasms. METHODS VE1 activity was assessed using immunohistochemistry in 90 mature B-cell neoplasms, including HCL (n = 17), HCL variant (n = 6), chronic lymphocytic leukemia (CLL) (n = 20), and 47 other B-cell lymphomas. Most (87/90) specimens were formalin-fixed, paraffin-embedded bone marrow (BM) biopsy specimens decalcified in either hydrochloric acid or formic acid. RESULTS VE1 was positive in 15 (88%) cases of HCL and two (10%) cases of CLL and was negative in all other tumors assessed. The VE1-positive HCL cases showed uniform staining in all tumor cells, but intensity was variable. The two VE1-negative HCL cases had BRAF V600 mutations proven by molecular analysis. The two CLL cases positive with VE1 showed an atypical staining pattern with expression in a minority of lymphoma cells. Immunohistochemistry using the VE1 antibody had a sensitivity of 88% and a specificity of 97% for HCL. CONCLUSIONS VE1 immunohistochemistry is a useful and convenient surrogate for detecting BRAF V600E mutation in BM biopsy specimens decalcified with hydrochloric or formic acid-based solutions.

An unusual case of a microscopic alveolar adenoma coexisting with lung carcinoma: a case report and review of the literature

IntroductionAlveolar adenomas are extremely rare, benign, primary lung tumors of unknown histogenesis that are characterized by proliferative type II alveolar epithelium and septal mesenchyma. Mostly incidental, they are clinically important as they can imitate benign primary and secondary malignant tumors and at times are difficult to differentiate from early-stage lung cancer. We describe the case of a 59-year-old man with an incidental microscopic alveolar adenoma coexisting with poorly differentiated lung carcinoma.Case presentationA 59-year-old Caucasian man with a medical history of smoking and chronic obstructive pulmonary disease was incidentally found to have a right upper lobe mass while undergoing a computed tomographic chest scan as part of a chronic obstructive pulmonary disease clinical trial. Our patient underwent a right upper lobectomy after a bronchoscopic biopsy of the mass revealed the mass to be a carcinoma. A pathological examination revealed an incidental, small, 0.2 cm, well circumscribed lesion on the staple line margin of the lobectomy in addition to the carcinoma. Histopathological and immunohistochemical examinations revealed the lesion to be an alveolar adenoma.ConclusionsWe report the rare presentation of a microscopic alveolar adenoma coexisting with lung carcinoma. Alveolar adenoma is an entirely benign incidental neoplasm that can be precisely diagnosed using immunohistochemical analysis in addition to its unique histopathological characteristics.

Chronic neutrophilic leukaemia

Chronic neutrophilic leukaemia (CNL) is a rare type of myeloproliferative neoplasm (MPN) characterised by sustained leucocytosis (≥25×109/L) with neoplastic proliferation of neutrophilic granulocytes in blood and bone marrow. In contrast to chronic myeloid leukaemia, the disease primarily involves neutrophilic lineage with persistent proliferation of mature forms of neutrophils. No consistent cytogenetic changes have been reported. Known recurrent genetic changes in other MPNs such as JAK2, MPL, CALR, BCR-ABL1, PDGFRA, PDGFRB and FGFR1 are mostly absent. Recently, mutations in colony stimulating factor 3 receptor (CSF3R) have been reported in high frequency in CNL. This discovery has provided more insight into its pathogenesis and opened up possible treatment options. In this article, we review the clinical findings, morphology, pathobiology and differential diagnosis of CNL and treatment implications of CSF3R mutations.

Therapy related acute myeloid leukemia with t(10:16): a rare entity

Treatment related myelodysplastic syndrome (t-MDS) and acute myeloid leukemia (t-AML) are well known complications after chemotherapy for various hematologic and non-hematologic malignancies. Alkylating agents and Topoisomerase inhibitors are most widely studied in this regard. There is growing concern about occurrence of t-MDS, t-MDS/AML and t-AML in patients of CLL treated with nucleoside analogues especially in combination with alkylating agents. Exact incidence and pathogenesis of nucleoside analogue related MDS/AML is not clear at this time. We hereby report a case of t-AML in a patient treated with Fludarabine, Cyclophosphamide and Rituximab (FCR) for CLL. The cytogenetic studies revealed a unique translocation t (10:16), that has been reported in very few cases of therapy related AML and pediatric AML.

Mitochondrial and glycolytic metabolic compartmentalization in diffuse large B-cell lymphoma

Metabolic heterogeneity between neoplastic cells and surrounding stroma has been described in several epithelial malignancies; however, the metabolic phenotypes of neoplastic lymphocytes and neighboring stroma in diffuse large B-cell lymphoma (DLBCL) is unknown. We investigated the metabolic phenotypes of human DLBCL tumors by using immunohistochemical markers of glycolytic and mitochondrial oxidative phosphorylation (OXPHOS) metabolism. The lactate importer MCT4 is a marker of glycolysis, whereas the lactate importer MCT1 and TOMM20 are markers of OXPHOS metabolism. Staining patterns were assessed in 33 DLBCL samples as well as 18 control samples (non-neoplastic lymph nodes). TOMM20 and MCT1 were highly expressed in neoplastic lymphocytes, indicating an OXPHOS phenotype, whereas non-neoplastic lymphocytes in the control samples did not express these markers. Stromal cells in DLBCL samples strongly expressed MCT4, displaying a glycolytic phenotype, a feature not seen in stromal elements of non-neoplastic lymphatic tissue. Furthermore, the differential expression of lactate exporters (MCT4) on tumor-associated stroma and lactate importers (MCT1) on neoplastic lymphocytes support the hypothesis that neoplastic cells are metabolically linked to the stroma likely via mutually beneficial reprogramming. MCT4 is a marker of tumor-associated stroma in neoplastic tissue. Our findings suggest that disruption of neoplastic-stromal cell metabolic heterogeneity including MCT1 and MCT4 blockade should be studied to determine if it could represent a novel treatment target in DLBCL.

Detection of Platelet Clumps on Peripheral Blood Smears by CellaVision DM96 System and Microscopic Review.

OBJECTIVE To determine and optimize the sensitivity of the CellaVision DM96 automated image-analysis system in detecting platelet (PLT) clumps on blood smears and to assess the reliability of the traditional laboratory practice of examining only the feather edge of the smear for PLT clumps. METHODS We processed 102 blood smears that revealed PLT clumps on microscopic review, using the CellaVision DM96, and reviewed the results for the ability of the analyzer to detect these clumps. We obtained the data regarding relative distribution of PLT clumps on different parts of the blood smear (feather edge, lateral edges, and readable area) from our microscopic-review observations. RESULTS The sensitivity of the Cellavision DM96 in detecting PLT clumps was between 40.4% and 82.8%, depending on the number of screens reviewed for this variable. Via microscopic review of the smears, the PLT-clump detection rate increased from 85.3%, obtained by examining only the feather edge, to 99.0%, obtained by examining the feather edge plus the readable area. CONCLUSION The sensitivity of the DM96 for detecting PLT clumps can be maximized to 82.8% by reviewing the entire white blood cell screen and the entire PLT screen. Microscopic review of the blood smears yielded a PLT-clump detection rate of 99.0% when we examined the feather edge and the readable area of the smear.

Bone and Joints

The chapter discusses several common orthopedic problems encountered by the surgical pathologist, in addition to some of the more commonly seen bone tumors and tumor-like lesions. Bone tumors are rare and not often seen on a day-to-day basis. Unfamiliarity with these tumors tends to make even relatively simple diagnoses more difficult. Additionally, it is important to have a team approach to the diagnosis of bone tumors and to include valuable information from the radiological studies and clinical details. The chapter emphasizes this and includes pertinent clinical and radiological details on the aforementioned tumors and systematically discusses trauma, infections, arthropathies, metabolic bone disease, and tumors using this integrated approach.

Chronic Myeloproliferative Neoplasm, Rare Types

Chronic neutrophilic leukemia (CNL) and chronic eosinophilic leukemia (CEL) are rare types of BCR/ABL1-negative myeloproliferative neoplasms characterized by neoplastic proliferation of neutrophilic granulocytes and eosinophilic granulocytes, respectively. Patients with CNL present with sustained proliferation of segmented neutrophils in blood and proliferation of neutrophilic granulocytes in bone marrow. Nearly all CNL patients possess somatic activating mutations in CSF3R gene, which is included as a new diagnostic criterion in the recent revision of WHO classification of hematolymphoid neoplasms. Diagnosis of CEL is based on sustained eosinophilia in blood and proliferation of eosinophils and precursors in bone marrow with either increase in blasts or demonstration of clonality. Recent studies have shown genomic abnormalities in up to 50% CEL. However, unlike CNL, no single recurrent-mutated gene was detected in CEL. The commonly noted mutations are ASXL1, TET2, EZH2, CBL1, and NOTCH1, which are likely not disease specific for CEL. Target therapies on CSF3R are currently under investigation.

Cerebral Amyloidoma Resulting from Central Nervous System Lymphoplasmacytic Lymphoma: A Case Report and Literature Review

Cerebral amyloidomas are rare cerebral mass lesions often associated with significant morbidity. Cerebral amyloid accumulation can be the result of a number of disease states and it is crucial for proper patient care to identify the pathogenic process leading to amyloidoma formation. Low grade clonal B-cell processes are one cause of cerebral amyloidomas. We report a case of an 87-year-old woman who presented with a lymphoplasmacytic lymphoma associated cerebral amyloidoma complicated by cerebral hemorrhage, discuss the proper workup of this disease entity, and present a review of the literature on this topic.

Feasibility of Counting Smudge Cells as Lymphocytes in Differential Leukocyte Counts Performed on Blood Smears of Patients With Established or Suspected Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma

Background Lymphocytosis and smudge cells are commonly observed on the blood smears of patients with an established or suspected diagnosis of chronic lymphocytic leukemia/small lymphocytic lymphoma. Excluding smudge cells from the manual differential count (MDIFF), a common laboratory practice, yields unreliable results and consequently necessitates performing the MDIFF testing on an albuminized blood smear. Objective To assess the reliability of counting smudge cells as lymphocytes in the MDIFFs on nonalbuminized smears and automated differentials (ADIFFs) as a substitute for MDIFFs. Methods We compared corresponding results of MDIFFs on nonalbuminized smears vs MDIFFs on albuminized smears (group A, n  = 82), ADIFFs vs MDIFFs on nonalbuminized smears (group B, n  = 68), and ADIFF vs MDIFFs on albuminized smears (group C, n  = 50). Smudge cells on the nonalbuminized smears were counted as lymphocytes. We focused on 2 white blood cell types: neutrophils and lymphocytes. Results Respective means for % lymphocytes and % neutrophils were 83.2 vs 83.2 and 14.0 vs 13.6 for Group A, 75.0 vs 77.0 and 20.2 vs 19.8 for Group B, and 76.1 vs 79.3 and 18.7 vs 17.4 for Group C. Respective correlation coefficients for % lymphocytes and % neutrophils were 0.92 and 0.94 for group A, 0.94 and 0.97 for group B, and 0.88 and 0.92 for group C. Conclusion Counting smudge cells as lymphocytes on nonalbuminized blood smears yielded reliable MDIFF results. Reportable ADIFF results were generated by the analyzer on 73% of the specimens, of which 93% were reliable.