Search Results (14)

Background and Clinical Significance: SWI/SNF chromatin remodeling complex-deficient malignancies constitute an aggressive group of undifferentiated tumors defined by inactivation of core subunits including SMARCA4 (BRG1) or SMARCB1 (INI1). In the head and neck, these tumors predominate in the sinonasal tract; oral cavity presentations are exceedingly rare, with reported cases predominantly representing metastatic disease. Peri-implant gingival masses in clinical practice are overwhelmingly reactive, but their occasional malignant nature mandates timely biopsy and thorough pathologic workup. We report the first comprehensively molecularly characterized case of a peri-implant gingival SWI/SNF complex-deficient tumor with confirmed biallelic SMARCA4 inactivation. Case Presentation: A 75-year-old man presented with a one-week history of a rapidly enlarging exophytic erythematous peri-implant gingival mass in the right posterior mandible (region 44–47). Incisional biopsy demonstrated an undifferentiated high-grade tumor with epithelioid, plasmablastoid, and focally rhabdoid morphology with necrosis. Immunohistochemistry showed complete loss of BRG1 (SMARCA4) with retained INI1 (SMARCB1), EMA positivity, Ki-67 of approximately 100%, and negativity across all lineage-specific markers (hematolymphoid, epithelial, melanocytic, endothelial, squamous). Comprehensive next-generation sequencing (Oncomine Comprehensive Assay Plus) confirmed biallelic SMARCA4 inactivation via a truncating nonsense mutation (p.Trp1346Ter; VAF 73.85%) combined with copy number loss, establishing the molecular mechanism underlying BRG1 protein loss. Co-occurring alterations included homozygous CDKN2A/CDKN2B deletion, MTAP loss (9p21.3), clonal TP53 and KEAP1 mutations, and intermediate–high tumor mutational burden (13.3 mutations/Mb) with microsatellite stability. The patient initiated carboplatin–paclitaxel and achieved a partial response at one month with further shrinkage by four months. This case illustrates a rare oral cavity manifestation of SWI/SNF complex deficiency arising in a peri-implant location, with a diagnostic workup that required integration of immunohistochemistry and molecular profiling for definitive characterization. The MTAP deletion co-occurring with homozygous CDKN2A/B loss identifies a potentially actionable synthetic lethal vulnerability to MAT2A and PRMT5 inhibitors currently under clinical investigation. An occult primary site could not be fully excluded due to absence of a dedicated staging workup. Conclusions: Rapidly enlarging peri-implant gingival masses should prompt timely biopsy and SWI/SNF marker testing when histology is high-grade and lineage-ambiguous. NGS-based molecular profiling confirms diagnosis, elucidates mechanism, and reveals actionable targets in this rare tumor class. Full article

Background: Merkel cell carcinoma (MCC) is a rare, aggressive primary cutaneous neuroendocrine carcinoma with a marked propensity for early regional lymph node metastasis. Although MCC most often arises on sun-exposed head and neck skin in older adults, tumors of the lower extremity are uncommon and may be mistaken for benign hemorrhagic lesions. Case presentation: A 54-year-old woman developed a rapidly enlarging, hemorrhagic mass in the left suprapatellar thigh. Magnetic resonance imaging demonstrated an extracompartmental subcutaneous soft-tissue mass without quadriceps muscle invasion. Wide local excision including the quadriceps fascia was performed. Histopathologic examination showed a dermal/subcutaneous small blue round cell neoplasm with brisk mitotic activity. Immunohistochemistry demonstrated diffuse cytoplasmic synaptophysin positivity, paranuclear dot-like CK20 reactivity, chromogranin A positivity, and negative MCPyV staining; TTF-1, S100, melan-A, HMB-45, and hematolymphoid markers were negative. Staging positron emission tomography/computed tomography identified ipsilateral inguinal nodal involvement. Therapeutic inguinal lymph node dissection revealed metastatic MCC in one of four lymph nodes without extranodal extension. The final stage was pT3 pN1b cM0 (AJCC 8th edition), corresponding to stage IIIB disease. Adjuvant radiotherapy (57 Gy in 20 fractions) was delivered to the primary bed and ipsilateral inguinal basin. The patient remains disease-free at 5-year follow-up. Conclusions: Lower-extremity MCC can mimic hemorrhagic or post-traumatic lesions, contributing to diagnostic delay. Persistent or rapidly enlarging “hematoma-like” lesions warrant early biopsy, and timely pathologic nodal staging is essential. Multimodal management can achieve durable control even in node-positive disease Full article

Primary effusion-based lymphomas are uncommon and may pose significant diagnostic challenges. Fluid overload-associated large B-cell lymphoma is a recently recognized entity in the 5th edition of the World Health Organization Classification of Hematolymphoid Tumors and should be included in the differential diagnosis of effusion-based lymphomas, particularly in elderly immunocompetent patients with conditions that predispose to fluid overload. Background and Clinical Significance: We report a case of fluid overload-associated large B-cell lymphoma to add to the limited literature and highlight distinguishing features from other primary effusion lymphomas. Case Presentation: A 77-year-old male with end-stage renal disease on hemodialysis and heart failure with reduced ejection fraction was admitted for respiratory failure and found to have a right-sided pleural effusion. Two pleural fluid specimens examined several weeks apart revealed sheets of large atypical lymphoid cells positive for CD20, Pax-5, CD79a, CD45, MUM1, BCL2, BCL6 (weak) and negative for TTF1, CD68, MOC31, BER EP4, WT1, Calretinin, CD3, CD138, CD30, and cMYC. Human Herpesvirus-8 and Epstein–Barr virus were negative. Staging showed a few mildly fluorodeoxyglucose-avid mediastinal lymph nodes which were benign. Ultimately, the patient was diagnosed with fluid overload-associated large B-cell lymphoma and treated with rituximab, cyclophosphamide, vincristine sulfate, and prednisone, but passed away three months after diagnosis. Conclusions: Fluid overload-associated large B-cell lymphoma is a new and important diagnostic consideration in effusion-based lymphomas. It may be mistaken for other conditions such as primary effusion lymphoma or other diffuse large B-cell lymphomas. The presence of a Human Herpesvirus-8-negative effusion-based lymphoma in an elderly immunocompetent patient without nodal or tissue involvement should prompt consideration of fluid overload-associated large B-cell lymphoma. Full article

Chimeric antigen receptor (CAR) T-cell infusion has led to improved outcomes in patients with B-lymphoblastic leukemia, B-cell lymphoma, and multiple myeloma. The spectrum of post-CAR T-cell hematolymphoid abnormalities is expanding, although they remain under-recognized. Pathologists play a key role in characterizing hematolymphoid proliferation after CAR T-cell therapy. This review presents clinical and pathologic findings of common hematolymphoid proliferation after CAR T-cell therapy, illustrated by selected cases. A review of the literature is presented in the context of individual cases, and our current understanding of the pathomechanism is discussed. Infused CAR T-cells undergo a series of four phases: distribution, expansion, contraction, and persistence. In the expansion phase, transient peripheral blood lymphocytosis occurs, reaching a peak two weeks post-infusion. Delayed contraction of CAR T-cells may give rise to hemophagocytic lymphohistiocytosis-like syndrome. Immune effector cell-associated enterocolitis presents in the persistence phase, about 3–6 months after infusion. Pathologic findings include a T-cell infiltrate in the intestinal mucosa and changes resembling graft versus host disease (GVHD). This entity requires differentiation from infections and from T-cell neoplasms, including those derived from CAR T-cells. Secondary myeloid malignancies follow the same pathways as therapy-related myeloid neoplasm but present with a shorter median latency. It is essential for pathologists to recognize post-CAR T-cell hematolymphoid proliferation to support clinical decision making in a high-risk patient population. Full article

Disease eponyms can be confusing, difficult to remember, scientifically non-robust, and lacking in implications on and relationships with cell lineage, histogenesis, and pathogenesis. This review is geared toward revisiting hematolymphoid diseases with eponyms in light of recent advances in technology and science by searching the past fifty years of the literature using Scopus and Google Scholar with the keywords “eponyms, hematolymphoid, diseases, lymphoma, benign, malignant, lymph node, spleen, liver, bone marrow, leukemia”. With advances in science and technology, there is accumulation of information on the morphologic nuances and immunologic, immunophenotypic, and genetic features of various hematolymphoid eponymic diseases, thus shedding light on important issues of etiology and pathogenesis with implications on therapy in various non-neoplastic (Castleman, Evans syndrome Kikuchi–Fujimoto, IgG4-related diseases) and neoplastic (Hodgkin, Burkitt, NK/T-cell lymphomas, dendritic/histiocytic neoplasms, and Sezary syndrome) diseases. This contributes to modern nomenclature, classification, subtyping, prognostication, and discoveries on new treatment strategies of hematolymphoid eponymic diseases. Full article

Myelodysplastic neoplasms (MDS) are a heterogenous clonal disorder of hemopoietic stem cells characterized by cytomorphologic dysplasia, ineffective hematopoiesis, peripheral cytopenias and risk of progression to acute myeloid leukemia (AML). Our understanding of this disease has continued to evolve over the last century. More recently, prognostication and treatment have been determined by cytogenetic and molecular data. Specific genetic abnormalities, such as deletion of the long arm of chromosome 5 (del(5q)), TP53 inactivation and SF3B1 mutation, are increasingly associated with disease phenotype and outcome, as reflected in the recently updated fifth edition of the World Health Organization Classification of Hematolymphoid Tumors (WHO5) and the International Consensus Classification 2022 (ICC 2022) classification systems. Treatment of lower-risk MDS is primarily symptom directed to ameliorate cytopenias. Higher-risk disease warrants disease-directed therapy at diagnosis; however, the only possible cure is an allogenic bone marrow transplant. Novel treatments aimed at rational molecular and cellular pathway targets have yielded a number of candidate drugs over recent years; however few new approvals have been granted. With ongoing research, we hope to increasingly offer our MDS patients tailored therapeutic approaches, ultimately decreasing morbidity and mortality. Full article

Peripheral T-cell lymphomas (PTCLs) are a rare subset of non-Hodgkin lymphomas that often carry significant difficulty in diagnosis and classification because of their rarity and biological complexity. Previous editions of the World Health Organization (WHO) classifications of hemopoietic neoplasms in 2001, 2008, and 2017 aimed to standardize hemopoietic neoplasm diagnosis in general. Since then, crucial clinico-pathological, immunophenotypic, and recent molecular discoveries have been made in the field of lymphomas, contributing to refining diagnostic criteria of several diseases, upgrading entities previously defined as provisional, and identifying new entities. In 2022, two different models were proposed to classify hematolymphoid neoplasms: the 5th edition of the WHO classification (WHO-HAEM5) and the International Consensus Classification (ICC). Of note, a common nosography is mandatory to ensure progress in health science and ensure the basis for a real precision medicine. In this article, the authors summarized the main differences with the previous fourth WHO edition and reviewed the main discrepancies between the two newest classifications, as far as PTCLs are concerned. Full article

The diagnosis and treatment of lymphoid neoplasms have undergone a continuously progressive positive change in the last three decades, with accelerated progress in the previous decade due to the advent of genomics in cancer diagnosis. Significantly, there has been an increasing emphasis on integrating molecular genetics with clinical, morphologic, immunophenotypic, and cytogenetic evaluation for diagnosis. As we think of moving forward with further advances in the genomics era, it is first helpful to understand our current state of knowledge and how we achieved it in the challenging and complex field of lymphoid neoplasms, which comprise very heterogeneous neoplastic diseases in children and adults, including clinically acute lymphoblastic leukemias (ALLs) arising from precursor lymphoid cells and clinically indolent and aggressive lymphomas arising from mature lymphoid cells. This work aims to provide an overview of the historical evolution and the current state of knowledge to anyone interested in the field of lymphoid neoplasms, including students, physicians, and researchers. Therefore, I discuss this complex topic in three review manuscripts, designated Parts 1–3. In Part 1, I explain the basis of the diagnostic classification of lymphoid neoplasms and its evolution up to the current fifth edition of the World Health Organization classification of hematolymphoid neoplasms, and the crucial importance of diagnostic tumor classifications in achieving and advancing patient care and precision medicine. In the second and third manuscripts, I discuss current diagnostic considerations for B-ALL and T-ALL (Part 2) and common indolent and aggressive mature leukemias/lymphomas (Part 3), including significant updates in the WHO 2022 classification, newly described entities, and concepts, including genetic predisposition to ALLs and lymphomas, and throughout emphasizing the essential integration of molecular genetics with clinical, morphologic (pathologic), immunophenotypic, and cytogenetic evaluation, as is required for precise diagnosis of the type of lymphoma/leukemia in any patient. Full article

The diagnosis and treatment of lymphoid neoplasms have undergone a continuously progressive positive change in the last three decades, with accelerated progress in the previous decade due to the advent of genomics in cancer diagnosis. Significantly, there has been an increasing emphasis on integrating molecular genetics with clinical, morphological, immunophenotypic, and cytogenetic evaluation for diagnosis. As we think of moving forward with further advances in the genomics era, it will be first helpful to understand our current state of knowledge and how we achieved it in the challenging and complex field of lymphoid neoplasms, which comprise very heterogeneous neoplastic diseases in children and adults, including clinically acute lymphoblastic leukemias (ALLs) arising from precursor lymphoid cells and clinically indolent and aggressive lymphomas arising from mature lymphoid cells. This work aims to provide an overview of the historical evolution and the current state of knowledge to anyone interested in the field of lymphoid neoplasms, including students, physicians, and researchers. Therefore, I have discussed this complex topic in three review manuscripts, designated Parts 1–3. In Part 1, I explain the basis of the diagnostic classification of lymphoid neoplasms and its evolution up to the current fifth edition of the World Health Organization classification of hematolymphoid neoplasms and the crucial importance of diagnostic tumor classifications in achieving and advancing patient care and precision medicine. In the second and third manuscripts, I discuss current diagnostic considerations for B-ALL and T-ALL (Part 2) and common indolent and aggressive mature leukemias/lymphomas (Part 3), including significant updates in the WHO 2022 classification, newly described entities, and concepts, including genetic predisposition to ALLs and lymphomas, and emphasizing throughout the essential integration of molecular genetics with clinical, morphologic, immunophenotypic, and cytogenetic evaluation, as required for the precise diagnosis of the type of lymphoma/leukemia in any patient. Full article

The diagnosis and treatment of lymphoid neoplasms have undergone a progressively positive change in the last three decades, with accelerated progress in the previous decade due to the advent of genomics in cancer diagnosis. Significantly, there has been an increasing emphasis on integrating molecular genetics with clinical, morphologic, immunophenotypic, and cytogenetic evaluation for diagnosis. As we consider moving forward with further advances in the genomics era, it is first helpful to understand our current state of knowledge and how we achieved it in the challenging and complex field of lymphoid neoplasms, which comprise very heterogeneous neoplastic diseases in children and adults, including clinically acute lymphoblastic leukemias (ALLs) arising from precursor lymphoid cells and clinically indolent and aggressive lymphomas arising from mature lymphoid cells. This work aims to provide an overview of the historical evolution and the current state of knowledge to anyone interested in the field of lymphoid neoplasms, including students, physicians, and researchers. Therefore, I have discussed this complex topic in three review manuscripts, designated Parts 1–3. In Part 1, I explain the basis of the diagnostic classification of lymphoid neoplasms and its evolution up to the current fifth edition of the World Health Organization (WHO) classification of hematolymphoid neoplasms and the crucial importance of diagnostic tumor classifications in achieving and advancing patient care and precision medicine. In the second and third manuscripts, I discuss current diagnostic considerations for B-ALL and T-ALL (Part 2) and common indolent and aggressive mature leukemias/lymphomas (Part 3), including significant updates in the WHO 2022 classification, newly described entities and concepts, including genetic predisposition to ALLs and lymphomas, and throughout emphasizing the essential integration of molecular genetics with clinical, morphologic (pathologic), immunophenotypic, and cytogenetic evaluation, as is required for precise diagnosis of the type of lymphoma/leukemia in any patient. Full article

(1) Background: Differential diagnosis using immunohistochemistry (IHC) panels is a crucial step in the pathological diagnosis of hematolymphoid neoplasms. In this study, we evaluated the prediction accuracy of the ImmunoGenius software using nationwide data to validate its clinical utility. (2) Methods: We collected pathologically confirmed lymphoid neoplasms and their corresponding IHC results from 25 major university hospitals in Korea between 2015 and 2016. We tested ImmunoGenius using these real IHC panel data and compared the precision hit rate with previously reported diagnoses. (3) Results: We enrolled 3052 cases of lymphoid neoplasms with an average of 8.3 IHC results. The precision hit rate was 84.5% for these cases, whereas it was 95.0% for 984 in-house cases. (4) Discussion: ImmunoGenius showed excellent results in most B-cell lymphomas and generally showed equivalent performance in T-cell lymphomas. The primary reasons for inaccurate precision were atypical IHC profiles of certain cases, lack of disease-specific markers, and overlapping IHC profiles of similar diseases. We verified that the machine-learning algorithm could be applied for diagnosis precision with a generally acceptable hit rate in a nationwide dataset. Clinical and histological features should also be taken into account for the proper use of this system in the decision-making process. Full article

Pericardial effusions can be caused by diverse etiologies, including heart-related conditions, kidney failure, trauma, infections, autoimmune diseases, and cancer. This systematic review aimed to assess the role of cytology in identifying the most prevalent cancers related to malignant pericardial effusions (MPEs), the ability of cytology, compared to histology, to detect cancer while evaluating pericardial effusions, and the prognostic impact of MPEs. Four electronic databases were investigated using a predefined algorithm, and specific inclusion and exclusion criteria. We found that the most prevalent primaries associated with MPEs were lung (especially NSCLCs), breast, hematolymphoid, and gastrointestinal cancers. MPEs tended to be hemorrhagic rather than serous or serosanguinous and to occupy larger volumes compared to non-neoplastic effusions. In addition, cytology was shown to exhibit an enhanced ability to detect cancer compared to biopsy in most of the included studies. Lastly, the presence of an MPE was associated with poor prognosis, while survival depended on the specific cancer type detected. Particularly, prognosis was found to be worse when MPEs were caused by lung or gastric cancer, rather than breast or hematolymphoid malignancies. In conclusion, evidence suggests that cytologic evaluation has a significant diagnostic and prognostic impact in patients with MPEs. Full article

Histiocytic sarcoma (HS) is a rare hematopoietic neoplasm derived from non-Langerhans histiocytic cells of the monocyte/macrophage system. With an incidence of 0.17/million individuals and a slight male preference, HS presents with a wide age distribution. Most commonly, it occurs as a primary malignancy. In approximately 25% of the cases a presumed transdifferentiation of a preexisting hematolymphoid disorder can be demonstrated. The clinical presentation varies from a localized solitary mass to severe disseminated disease often with extranodal involvement including skin, soft tissue, the gastrointestinal tract and the hematopoietic system. Systemic symptoms in terms of weight loss, fever and night sweats often occur. The diagnostic work-up of HS is extremely challenging due to the rarity of the disease as well as a wide differential diagnosis in terms of a histologic overlap with diverse mimics. No standardized treatment for HS exists and especially in a disseminated disease the clinical course is overly aggressive with a dismal outcome. The median overall survival from the time of diagnosis is approximately six months. We report a 43-year-old previously healthy Caucasian male admitted to our hospitals with abdominal pain and a feeling of fatigue. We demonstrate both the challenges of a correct diagnosis and an effective treatment as well as the aggressive nature of histiocytic sarcoma. Full article

The first discovered human retrovirus, Human T-Lymphotropic Virus type 1 (HTLV-1), is responsible for an aggressive form of T cell leukemia/lymphoma. Mouse models recapitulating the leukemogenesis process have been helpful for understanding the mechanisms underlying the pathogenesis of this retroviral-induced disease. This review will focus on the recent advances in the generation of immunodeficient and human hemato-lymphoid system mice with a particular emphasis on the development of mouse models for HTLV-1-mediated pathogenesis, their present limitations and the challenges yet to be addressed. Full article