Basic immunohistochemistry for lymphoma diagnosis

Long-term survival outcomes of 'watch and wait' in patients with bronchus-associated lymphoid tissue lymphoma: a multicenter real-world data analysis in Korea

Bronchus-associated lymphoid tissue (BALT) is a rare cause of extranodal marginal zone lymphoma (MZL). Although most patients with BALT lymphoma (BALToma) show an indolent clinical course and are monitored without treatment, there are limited real-world data on the long-term outcome of "watch-and-wait' strategy in comparison with other treatments. The survival outcomes of patients newly diagnosed with BALToma at three tertiary hospitals in Korea undergoing two treatment strategies were analyzed: group A, patients who were monitored without any treatment or received only radiotherapy after diagnosis; and group B, patients receiving any kind of systemic chemotherapy after diagnosis, regardless of their history of any local treatment such as surgery or radiotherapy. Of the 67 patients included in our analysis, the 10-year progression-free survival (PFS) and 10-year overall survival (OS) rates were 65.3% and 83.2%, respectively. The 10-year PFS rates for observation or localized treatment and systemic chemotherapy were 78.7% and 56.9%, respectively (p = 0.044). Ten-year OS rates for observation or localized treatment and systemic chemotherapy were 100% and 71.7%, respectively (p = 0.016). Multivariate analysis showed that bilateral lung (HR 2.462, p = 0.047) and extrapulmonary organ (HR 4.485, p = 0.004) involvement were the only significant factors associated with poor PFS. Prognostic factor analysis for OS did not yield significant results. Patients with BALToma show a favorable prognosis, suggesting that observation or localized therapy alone may be effective for patient management. However, patients with bilateral lung or extrapulmonary involvement may require careful monitoring for disease progression and more aggressive treatment approaches.

Assessment of Ki-67 Proliferative Index in Cytological Samples of Nodal B-Cell Lymphomas

BACKGROUND

The Ki-67 proliferative index (PI) is part of the diagnosis of nodal B-cell lymphoma (nBCL), but its determination in cytological samples is not standardized. We aimed to establish an approach for the accurate determination of the Ki-67 PI in cytological slides to differentiate between indolent and aggressive nBCLs.

METHODS

Patients diagnosed with nBCL by fine-needle aspiration biopsy and subsequent excision biopsy were included. Cell suspensions were prepared from biopsy samples for CD3/Ki-67 double immunocytochemical staining and flow-cytometric verification of lymphoma B-cell counts. The Ki-67 PI was assessed by manual counting and eyeballing in cytology and eyeballing in histology. The cut-off values for the differentiation between aggressive and indolent lymphomas were determined for each method.

RESULTS

A strong correlation between manual and flow-cytometric counting of lymphoma B cells was confirmed (interclass correlation coefficient (IC coef.) = 0.78). The correlation of the Ki-67 PI determined in cytological and histological slides was also strong (IC coef. > 0.80). Histologically, 55 cases were classified as indolent and 31 as aggressive nBCLs. KI-67 PI cut-off values of 28.5%, 27.5%, and 35.5% were established for manual counting and eyeballing in cytology and eyeballing in histology, respectively, with high sensitivity and specificity.

CONCLUSIONS

The Ki-67 PI, assessed by manual counting and eyeballing in cytological samples, accurately differentiates between indolent and aggressive nBCLs.

EBV Positive Diffuse Large B Cell Lymphoma with Negative Pan-B Cell Markers, Case Report, and Literature Review

Most B cell lymphomas are positive for one or more B cell markers including CD19, CD20, CD79a, or PAX5. However, rare cases of mature B cell lymphoma not expressing any B cell markers have been characterized and recognized as distinct diagnostic entities by current classification guidelines, including plasmablastic lymphoma, primary effusion lymphoma, and ALK-positive large B cell lymphoma. We present a case of pan-B cell marker negative, EBV positive diffuse large B cell lymphoma that is positive for OCT2, BOB1, and clonal immunoglobulin gene rearrangement that does not meet diagnostic criteria for any B cell lymphoma by current 4th and 5th Ed beta version WHO Hematolymphoid Tumors classification. In challenging cases like the one presented, utilizing OCT2 and BOB1 immunohistochemical stains can assist in determining B cell lineage. The WHO tumor classification system should consider adding OCT2 and BOB1 as alternative B cell lineage markers into their corresponding categories.

The Importance of Intestinal Microbiota and Dysbiosis in the Context of the Development of Intestinal Lymphoma in Dogs and Cats

Recent advancements have significantly enhanced our understanding of the crucial role animal microbiomes play in veterinary medicine. Their importance in the complex intestinal environment spans immune modulation, metabolic homeostasis, and the pathogenesis of chronic diseases. Dysbiosis, a microbial imbalance, can lead to a range of diseases affecting both individual organs and the entire organism. Microbial disruption triggers inflammatory responses in the intestinal mucosa and disturbs immune homeostasis, increasing susceptibility to toxins and their metabolites. These dynamics contribute to the development of intestinal lymphoma, necessitating rigorous investigation into the role of microbiota in tumorigenesis. The principles explored in this study extend beyond veterinary medicine to encompass broader human health concerns. There are remarkable parallels between the subtypes of lymphoproliferative disorders in animals and humans, particularly Hodgkin's lymphoma and non-Hodgkin's lymphoma. Understanding the etiology of a cancer of the lymphatic system formation is critical for developing both preventive strategies and therapeutic interventions, with the potential to significantly improve patient outcomes. The aim of this study is to discuss the optimal composition of the microbiome in dogs and cats and the potential alterations in the microbiota during the development of intestinal lesions, particularly intestinal lymphoma. Molecular and cellular analyses are also incorporated to detect inflammatory changes and carcinogenesis. A review of the literature on the connections between the gut microbiome and the development of lymphomas in dogs and cats is presented, along with potential diagnostic approaches for these cancers.

MHC1/LILRB1 axis as an innate immune checkpoint for cancer therapy

Immune checkpoint blockades (ICBs) have revolutionized cancer therapy through unleashing anti-tumor adaptive immunity. Despite that, they are usually effective only in a small subset of patients and relapse can occur in patients who initially respond to the treatment. Recent breakthroughs in this field have identified innate immune checkpoints harnessed by cancer cells to escape immunosurveillance from innate immunity. MHC1 appears to be such a molecule expressed on cancer cells which can transmit a negative signal to innate immune cells through interaction with leukocyte immunoglobulin like receptor B1 (LILRB1). The review aims to summarize the current understanding of MHC1/LILRB1 axis on mediating cancer immune evasion with an emphasis on the therapeutic potential to block this axis for cancer therapy. Nevertheless, one should note that this field is still in its infancy and more studies are warranted to further verify the effectiveness and safety in clinical as well as the potential to combine with existing immune checkpoints.

Diffuse large B-cell lymphoma-induced intussusception: A case report and literature review

Adult intussusception necessitates early surgical intervention. We emphasis the significance of considering diffuse large B-Cell lymphoma in differential diagnoses for adult intussusception, particularly in the colon, to ensure precise diagnosis and optimal management.

An evidence based immunohistochemical panel for diagnosing oral lymphoma along with a case series

Oral lymphomas are rare and present a diagnostic challenge. Immunophenotyping is essential to decipher their biology and identify therapeutic targets. Histopathology can prove to be diagnostically difficult to type these lesions, and hence, immunohistochemistry (IHC) proves useful in deciphering their biology. Here, we present an evidence-based approach using a novel immunohistochemical marker panel to diagnose oral lymphomas by discussing four unique cases.

Immunocytochemistry on frozen-embedded cell block for the diagnosis of hematolymphoid cytology specimen: a straightforward alternative to the conventional cell block

Agarose-based cell block (CB) technique can be modified to be combined with the frozen section technique for the preparation of a high-quality frozen-embedded CB (F-CB) from an effusion or fine-needle aspiration (FNA) cytology sample. This combined technique can be effectively used for the immunocharacterization of the hematolymphoid cells on F-CB. To demonstrate the applicability of performing diagnostic ICC on F-CB, we have analyzed the immunophenotype of the hematolymphoid cells in a series of eight cases of effusions and eight cases of FNA cytology specimens by using CB-ICC on sections cut from frozen-embedded CBs. The SurePathTM residue or cytologic material scraped off from the FNA cytology smear that was diagnostic for or suspicious of hematolymphoid malignancy was pelleted and pre-embedded in agarose. Half of the agarose-embedded pellet was frozen-embedded in OCT compound for the preparation of F-CB, while the other half was processed for the preparation of paraffin-embedded CB. Sections cut from the F-CB and P-CB were used for CB-ICC. Panels of ICC on the F-CBs could enable the immunocytochemical differential diagnosis of large cell hematologic malignancies that encompass anaplastic large cell lymphoma and other forms of large-cell hematolymphoid malignancies such as large B-cell lymphomas, anaplastic plasma cell myeloma, myeloid sarcoma, and T-lymphoblastic lymphoma. It also appeared that the small B-cell lymphomas in the effusions or FNAs could be differentially diagnosed with the aid of CB-ICC on the F-CB. A modified agarose-based CB technique can be combined with the frozen-embedded CB method for the preparation of F-CB that can be directly used for the immunocytochemical differential diagnosis of hematolymphoid cytology samples.

Advances in cellular and tissue-based imaging techniques for sarcoid granulomas

Sarcoidosis embodies a complex inflammatory disorder spanning multiple systems, with its origin remaining elusive. It manifests as the infiltration of inflammatory cells that coalesce into distinctive noncaseous granulomas within afflicted organs. Unraveling this disease necessitates the utilization of cellular or tissue-based imaging methods to both visualize and characterize the biochemistry of these sarcoid granulomas. Although hematoxylin and eosin stain, standard in routine use alongside cytological stains have found utility in diagnosis within clinical contexts, special stains such as Masson's trichrome, reticulin, methenamine silver, and Ziehl-Neelsen provide additional varied perspectives of sarcoid granuloma imaging. Immunohistochemistry aids in pinpointing specific proteins and gene expressions further characterizing these granulomas. Finally, recent advances in spatial transcriptomics promise to divulge profound insights into their spatial orientation and three-dimensional (3-D) molecular mapping. This review focuses on a range of preexisting imaging methods employed for visualizing sarcoid granulomas at the cellular level while also exploring the potential of the latest cutting-edge approaches like spatial transcriptomics and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), with the overarching goal of shedding light on the trajectory of sarcoidosis research.

Nasopharyngeal Lymphoma: Rare Case Report

A case of Nasopharyngeal Non Hogkins lypmhomas, diagnosed on Histopathology (HPE) and immunohistochemistry. In this case report we present the clinical presentation, diagnosis and treatment protocol of nasopharyngeal NHL.

A stepwise approach to fine needle aspiration cytology of lymph nodes

The cytological diagnosis of lymph node lesions is extremely challenging because of the diverse diseases that cause lymph node enlargement, including both benign and malignant or metastatic lymphoid lesions. Furthermore, the cytological findings of different lesions often resemble one another. A stepwise diagnostic approach is essential for a comprehensive diagnosis that combines: clinical findings, including age, sex, site, multiplicity, and ultrasonography findings; low-power reactive, metastatic, and lymphoma patterns; high-power population patterns, including two populations of continuous range, small monotonous pattern and large monotonous pattern; and disease-specific diagnostic clues including granulomas and lymphoglandular granules. It is also important to remember the histological features of each diagnostic category that are common in lymph node cytology and to compare them with cytological findings. It is also essential to identify a few categories of diagnostic pitfalls that often resemble lymphomas and easily lead to misdiagnosis, particularly in malignant small round cell tumors, poorly differentiated squamous cell carcinomas, and nasopharyngeal undifferentiated carcinoma. Herein, we review a stepwise approach for fine needle aspiration cytology of lymphoid diseases and suggest a diagnostic algorithm that uses this approach and the Sydney classification system.

Anal lymphoma: a tumor with insufficient attention

BACKGROUND

Anal lymphomas are extremely rare. There are no relevant descriptions in professional books, and there are only a few case reports in the literature. Here, we report a new case and review the literature to summarize the clinical and pathological features of anal lymphoma.

METHODS

We described a case of anal lymphoma confirmed by pathological diagnosis, then searched the PubMed database, and finally selected 12 reported cases to be included in the study. We described the clinical and pathological characteristics of the patients.

RESULTS

Thirteen patients with anal lymphoma were confirmed. Seven men and six women with a median age of 50. There were four cases of HIV- and EBV-infected patients. The size of the tumor was 1-13 cm, all of which were diagnosed as B-cell lymphoma, and 61.5% were diffuse large B-cell lymphomas. Among the 13 patients, eight received chemotherapy or immunochemotherapy, two received radiotherapy, one received chemotherapy combined with radiotherapy, one received surgery, and one gave up treatment. Three patients died, and only 2 of 10 surviving patients had complete remission.

CONCLUSION

Anal lymphoma is extremely rare. Patients with persistent abscess complicated with HIV or EBV infection should undergo pathological biopsy to exclude anal lymphoma.

Immunohistochemical Profile of Parathyroid Tumours: A Comprehensive Review

Immunohistochemistry remains an indispensable tool in diagnostic surgical pathology. In parathyroid tumours, it has four main applications: to detect (1) loss of parafibromin; (2) other manifestations of an aberrant immunophenotype hinting towards carcinoma; (3) histogenesis of a neck mass and (4) pathogenetic events, including features of tumour microenvironment and immune landscape. Parafibromin stain is mandatory to identify the new entity of parafibromin-deficient parathyroid neoplasm, defined in the WHO classification (2022). Loss of parafibromin indicates a greater probability of malignant course and should trigger the search for inherited or somatic CDC73 mutations. Aberrant immunophenotype is characterised by a set of markers that are lost (parafibromin), down-regulated (e.g., APC protein, p27 protein, calcium-sensing receptor) or up-regulated (e.g., proliferation activity by Ki-67 exceeding 5%) in parathyroid carcinoma compared to benign parathyroid disease. Aberrant immunophenotype is not the final proof of malignancy but should prompt the search for the definitive criteria for carcinoma. Histogenetic studies can be necessary for differential diagnosis between thyroid vs. parathyroid origin of cervical or intrathyroidal mass; detection of parathyroid hormone (PTH), chromogranin A, TTF-1, calcitonin or CD56 can be helpful. Finally, immunohistochemistry is useful in pathogenetic studies due to its ability to highlight both the presence and the tissue location of certain proteins. The main markers and challenges (technological variations, heterogeneity) are discussed here in the light of the current WHO classification (2022) of parathyroid tumours.