Cytological Diagnosis of T Lymphoblastic Leukemia/Lymphoma in Patients with Pleural Effusion as an Initial Clinical Presentation: Two Case Reports of an Algorithmic Approach Using Complete Immunohistochemical Phenotyping

Urinary cytologic features of primitive neuroectodermal tumor primarily involving the kidney: A case report

Renal primitive neuroectodermal tumor(rPNET) is an extremely rare and distinct entity that can be mistaken for a variety of other round cell tumors. Findings from fine needle aspiration cytology have been reported, but there have been no reports of PNET cytomorphological features in urine cytology specimen. Here, we report a case of PNET characterized by urine cytology. A 24-year-old girl presented with hematuria for half a month. Computed tomography showed a large tumor involving the upper pole of the right kidney. Urinary cytology exhibited highly cellular clusters composed of small, round, atypical cells with little cytoplasm and a high nuclear/cytoplasmic ratio. Following a right nephrectomy, the biopsy confirmed the diagnosis of rPNET. Additionally, immunohistochemistry (IHC) staining of the decolorized liquid-based cytology slide was positive for CD99, further confirming the diagnosis through urine cytology. Our observations suggest that urinary cytology in combination with cytological morphology and immunocytochemistry may be a potentially useful method for the detection of PNET.

Hematolymphoid Neoplasms in Serous Effusions: Morphological Spectrum, Distribution, and Role of Ancillary Techniques—A Retrospective Analysis of 75 cases

Introduction Involvement of body fluids can occur at the time of diagnosis or during the disease course of hematolymphoid neoplasms. Cytodiagnosis of malignant effusion is important in effective clinical management.

Objectives (1) The aims of the study were to determine the frequency of distribution of various hematolymphoid neoplasms involving body fluids, (2) to study the morphology of hematolymphoid neoplasms in fluids, and (3) to assess the role of ancillary techniques in the diagnosis.

Materials and Methods In this retrospective study, all cases of hematolymphoid neoplasms involving body fluids diagnosed from January 2016 to December 2018 were evaluated.

Results During the 3-year period, there were 75 cases of hematological malignancies involving body fluids. These included 48 male patients and 27 female patients. Pleural fluid was involved in majority of cases (56 cases; 74.67%), followed by ascitic fluid (17 cases; 22.67%), and pericardial fluid (2 cases; 2.67%). High cellularity, monotonous population of cells, high nuclear-cytoplasmic (N/C) ratio, indentation/irregularity of nuclear membrane, immature chromatin/irregular clumping of chromatin, increased mitosis, and karyorrhexis were the key features which helped to differentiate between reactive and neoplastic processes. There were 35 cases of B-cell neoplasms, 33 cases of T-cell neoplasms, and seven cases of myeloid neoplasms involving body cavity fluids. T-lymphoblastic lymphoma was the most common subtype (29 cases; 38.7%), followed by diffuse large B-cell lymphoma (DLBCL) (12 cases; 16%). In 53 cases, effusion was present in the initial presentation itself. Initial diagnosis was made in effusion cytology in 25 cases (33.33% of the total), with the help of flow cytometry in 20 cases, and immunohistochemistry (IHC) in cell blocks in five cases.

Conclusion Diagnosis of hematolymphoid neoplasms in body fluids based on correlation with clinical details, critical evaluation of cytology findings, and comparison with previous diagnosis along with the judicious use of ancillary techniques helps in deciding an early treatment plan.

A Simple and Practical Guide for Triaging Lymphocyte-rich Effusions for Ancillary Studies

Lymphocyte-rich effusions of the body cavities may represent a reactive/benign condition, primary effusion lymphoma, or systemic lymphoma with secondary malignant effusion, either as initial presentation or as a late complication. Cytomorphologic examination is essential and fundamental for diagnosis and may provide important clues to the nature of diseases. However, based on morphology alone, cytologic diagnosis of lymphocyte-rich effusions could be very challenging, particularly when the lymphocytes are small. Cytologists/cytopathologists might be uncertain when a lymphocyte-rich effusion specimen warrants a comprehensive hematopathologic workup. Herein we present a simple and practical algorithmic approach. On the basis of the cytomorphology of lymphocytes (small vs. large cells), presence or absence of cellular atypia, and clinical information (an earlier history or current lymphoma), the lymphocyte-rich effusion samples could be triaged for ancillary studies including immunophenotyping and molecular assays if indicated. Incorporation of cytomorphology, correlation with clinical information, and appropriate application of various ancillary techniques is mandatory for a correct diagnosis of lymphocyte-rich effusion specimens.

Lymphomas of the Mediastinum and Their Differential Diagnosis

Lymphoma is the most common malignancy involving the mediastinum but can be challenging to diagnose on small biopsy specimens. This review provides a pattern-based approach to help triage small tissue samples for the diagnosis of mediastinal lymphoid proliferations, with focus on the main primary mediastinal lymphomas. The use of ancillary studies is highlighted, along with considerations to avoid misdiagnosis and scenarios to request additional tissue.

Primary Mediastinal Nodal and Extranodal Non-Hodgkin Lymphomas: Current Concepts, Historical Evolution, and Useful Diagnostic Approach: Part 2

Primary mediastinal non-Hodgkin lymphomas (PM-NHLs) represent ∼5% of all non-Hodgkin lymphomas (NHLs) and comprise lymphomas of B-cell and T-cell origin. PM-NHLs are defined as involvement of mediastinal lymph nodes, thymus, and/or mediastinal organs (heart, lung, pleura, pericardium) by NHL without evidence of systemic disease at presentation. The clinical scenario is variable and depends on the lymphoma subtype. The radiologic presentation is also variable ranging from a mediastinal mass with or without superior vena cava syndrome, a pleural or a cardiac mass associated with effusion, or as an effusion only. The diagnosis of PM-NHLs can only be established by microscopic evaluation, and therefore, general pathologists should be aware of these tumors and familiar with their diagnostic approach. The most common anterior mediastinal NHLs (90% to 95%) are primary mediastinal (PM) large B-cell lymphoma and T-lymphoblastic lymphoma. Thymic marginal zone lymphoma and mediastinal gray zone lymphoma are very rare. The remainder PM-NHLs involving middle or posterior mediastinum include diffuse large B-cell lymphoma (DLBCL) and rare cases of T-cell lymphoma, including anaplastic large cell lymphoma and breast implant-associated anaplastic large cell lymphoma extending to the anterior mediastinum. Primary pleural and cardiac NHLs are mostly DLBCLs. Other rare subtypes of PM-NHLs include DLBCL associated with chronic inflammation/pyothorax-associated lymphoma, fibrin-associated DLBCL (both Epstein-Barr virus positive), and pleural and/or pericardial primary effusion lymphoma (human herpesvirus-8 positive/Epstein-Barr virus positive). We review the historical aspects, epidemiology, clinicoradiologic features, histopathology, immunohistochemistry, differential diagnosis, and relevant cytogenetic and molecular features of the remaining mediastinal B-cell lymphomas, including primary thymic marginal zone lymphoma of the mucosa-associated lymphoid tissue type, other PM small B-cell lymphomas, PM plasmacytoma, and the most relevant PM T-cell lymphomas.

Hematolymphoid neoplasms in effusion cytology

Background:

Hematolymphoid neoplasms (HLNs) presenting as body cavity effusions are not a common finding. They may be the first manifestation of the disease. A diagnosis on effusion cytology may provide an early breakthrough for effective clinical management.

Aims:

Study the cytomorphology of HLNs in effusion cytology, determine common types, sites involved and uncover useful cytomorphologic clues to subclassify them.

Materials and Methods:

Twenty-four biopsy-proven HLN cases with malignant body cavity effusions and 8 cases suspicious for HLN on cytology but negative on biopsy are included in this study. Effusion cytology smears were reviewed for cytomorphological features: cellularity, cell size, nuclear features, accompanying cells, karyorrhexis, and mitoses.

Results:

Diffuse large B-cell lymphoma (37%) was the most common lymphoma type presenting as effusion followed by peripheral T-cell lymphoma (25%). Pleural effusion (75%) was most frequent presentation followed by peritoneal effusion (20.8%). Pericardial effusion was rare (4.1%). The common cytologic features of HLNs in effusions: high cellularity, lymphoid looking cells with nuclear enlargement, dyscohesive nature, and accompanying small lymphocytes. Mitosis and karyorrhexis were higher in high-grade HLNs when compared to low-grade HLNs. Myelomatous effusion showed plasmacytoid cells. Very large, blastoid looking cells with folded nuclei, high N: C ratio, and prominent nucleoli were seen in leukemic effusion.

Conclusion:

HLNs have characteristic cytomorphology and an attempt to subclassify them should be made on effusion cytology. Reactive lymphocyte-rich effusions cannot be distinguished from low-grade lymphomas based on cytomorphology alone. Ancillary tests such as immunocytochemistry, flow cytometry, and/or molecular techniques may prove more useful in this regard.

Forty-nine cases of acute lymphoblastic leukaemia/lymphoma in pleural and pericardial effusions: A cytological-histological correlation

INTRODUCTION

Acute lymphoblastic leukaemia/lymphoma (ALL/LBL) is an aggressive entity of precursor lymphoid neoplasm and may cause malignant serous effusion (SE). The current study aimed to analyse the characteristics of SE cytology of ALL/LBL including cytomorphology, immunophenotyping, clonality and evaluate the effectiveness of SE cytology as a diagnostic method for ALL/LBL.

METHODS

SE specimens with final diagnosis of ALL/LBL from 2006 to 2016 were reviewed for clinical data, cytomorphological features and ancillary studies. Cytodiagnoses were compared with histodiagnoses, and the discordant cases were analysed.

RESULTS

A total of 49 specimens including 47 pleural fluids and 2 pericardial fluids from 49 patients were evaluated. Cytomorphology revealed lymphoblasts varied from small size with scant cytoplasm, condensed nuclear chromatin and indistinct nucleoli to large size with dispersed nuclear chromatin and multiple variably prominent nucleoli. Nuclear clefts and hand mirror-shaped blasts were demonstrated. The positive rates of CD99 and terminal deoxynucleotidyl transferase were 90.9% and 81.6%, respectively. Both monoclonal immunoglobulin (Ig)H and T-cell receptor-γ gene rearrangements were demonstrated in 1 of 3 cases. Monoclonal T-cell receptor-γ gene rearrangement was found in 10 of 11 cases. Monoclonal IgH and/or Ig? gene rearrangements were revealed in 2 of 3 cases. Cytodiagnoses included 4 ALL/LBL, 3 B-ALL/LBL and 42 T-ALL/LBL. Histodiagnoses were available in 24 cases including 2 ALL/LBL, 2 B-ALL/LBL and 20 T-ALL/LBL. The concordance rates of cytological-histological diagnoses were 66.7%, 0% and 95.2% in the three categories, respectively. There were 3 cases with discrepancies of cell lineages.

CONCLUSIONS

SE cytological evaluation is a reliable and effective method for the diagnosis of ALL/LBL.

In vitro and in vivo assessment of direct effects of simulated solar and galactic cosmic radiation on human hematopoietic stem/progenitor cells

Future deep space missions to Mars and near-Earth asteroids will expose astronauts to chronic solar energetic particles (SEP) and galactic cosmic ray (GCR) radiation, and likely one or more solar particle events (SPEs). Given the inherent radiosensitivity of hematopoietic cells and short latency period of leukemias, space radiation-induced hematopoietic damage poses a particular threat to astronauts on extended missions. We show that exposing human hematopoietic stem/progenitor cells (HSC) to extended mission-relevant doses of accelerated high-energy protons and iron ions leads to the following: (1) introduces mutations that are frequently located within genes involved in hematopoiesis and are distinct from those induced by γ-radiation; (2) markedly reduces in vitro colony formation; (3) markedly alters engraftment and lineage commitment in vivo; and (4) leads to the development, in vivo, of what appears to be T-ALL. Sequential exposure to protons and iron ions (as typically occurs in deep space) proved far more deleterious to HSC genome integrity and function than either particle species alone. Our results represent a critical step for more accurately estimating risks to the human hematopoietic system from space radiation, identifying and better defining molecular mechanisms by which space radiation impairs hematopoiesis and induces leukemogenesis, as well as for developing appropriately targeted countermeasures.