Distinct Clinicopathologic Entity Research Articles

PATH-35. INTEGRATED GENOMIC ANALYSES OF IMMUNODEFICIENCY-ASSOCIATED EPSTEIN-BARR VIRUS- (EBV) POSITIVE PRIMARY CNS LYMPHOMAS

Abstract Immunodeficiency-associated primary CNS lymphoma (PCNSL) represents a distinct clinicopathological entity, which is typically Epstein-Barr virus positive (EBV+) and carries an inferior prognosis. Genetic alterations that characterize EBV related CNS lymphomagenesis remain unclear precluding molecular classification and targeted therapies. In this study, a comprehensive genetic analysis of 22 EBV+ PCNSL, integrated clinical and pathological information with exome and RNA sequencing (RNASeq) data. Deconvolution of bulk RNA sequencing data was performed using CIBERSORTx to characterize the tumor microenvironment. EBV+ PCNSL with germline controls carried a median of 55 protein-coding single nucleotide variants (SNVs; range 24-217) and 2 insertions/deletions (range 0-22). Genetic landscape was largely shaped by aberrant somatic hypermutation with a median of 41.01% (range 31.79-53.49%) of SNVs mapping to its target motifs. Tumors lacked established SNVs (MYD88, CD79B, PIM1) and copy number variants (CDKN2A, HLA loss) driving EBV negative PCNSL. Instead, EBV+ PCNSL were characterized by SOCS1 mutations (26%), predicted to disinhibit JAK/STAT signaling, and mutually exclusive gain-of-function NOTCH pathway SNVs (26%). Copy number gains were enriched on 11q23.3, a locus directly targeted for chromosomal aberrations by EBV, that includes SIK3 known to protect from cytotoxic T-cell responses. Losses covered 5q31.2 (STING), critical for sensing viral DNA, and 17q11 (NF1). Unsupervised clustering of RNASeq data revealed two distinct transcriptional groups, that shared strong expression of CD70 and IL1R2, previously linked to tolerogenic tumor microenvironments. Correspondingly, deconvolution of bulk RNASeq data revealed elevated M2-macrophage, T-regulatory cell, mast cell and monocyte fractions in EBV+ PCNSL. In addition to novel insights into the pathobiology of EBV+ PCNSL, the data provide the rationale for the exploration of targeted therapies including JAK-, NOTCH- and CD70-directed approaches.

Zoon balanitis: not a distinct clinicopathological entity?

Zoon balanitis (ZB) was originally described in the 1950s in patients with clinical features resembling erythroplasia of Queyrat, but with histology that demonstrated a plasma cell infiltrate without evidence of dysplasia. Subsequently, ZB has been extensively reported in the literature, reflecting widespread acknowledgement as an established distinct clinicopathological entity. However, its existence as such has been questioned and there have been suggestions in the literature that ZB represents either a non-specific irritant reaction pattern, or a part of the heterogenous clinicopathological complex of male genital lichen sclerosus (MGLSc). In this study, the entire historical literature of published cases of ZB was subject to review, to determine respectively whether clinical or histological features of MGLSc had been present and been overlooked. One hundred and one papers were reviewed. Seventy-five contained images purporting to be of ZB. Images that were deemed to be of inadequate quality or to present uninformative anatomical views were excluded. The images in 66 manuscripts were amenable to scrutiny; 98.5% of these images demonstrated clinical signs of MGLSc, such as adhesions, effacement of the coronal sulcus and the frenulum, tightening of the prepuce, constrictive posthitis, etiolation of the glans, lichenoid inflammation and sclerosis. These findings strongly suggest that ZB occurs in the vast majority of cases as a manifestation of MGLSc and that its recognition as a distinct clinicopathological entity should be questioned, if not discontinued.

Clinical, neuropathological, and molecular characteristics of rapidly progressive dementia with Lewy bodies: a distinct clinicopathological entity?

BackgroundThe term rapidly progressive dementia (RPD) with Lewy bodies (rpDLB) is used for DLB patients who develop a rapidly progressive neurological syndrome and have reduced survival. Here, we characterise the clinical, neuropathological, and molecular characteristics of a large rpDLB neuropathological series.MethodsWe included all RPD patients with a disease duration < 4 years submitted to our prion disease referral centre between 2003 and 2022 who showed Lewy body pathology (LBP) in limbic or neocortical stages as primary neuropathological diagnosis, had no systemic condition justifying the rapid deterioration and were previously neurologically unimpaired. Clinical features were retrieved and compared with Creutzfeldt-Jakob disease (CJD) and rapidly progressive Alzheimer’s disease (rpAD) cohorts. Neuropathological and genetic (whole exome sequencing, APOE genotyping, and C9orf72 repeat expansion analysis) characteristics of rpDLB patients were systematically investigated. We scored semi-quantitatively the LBP load and performed a α-synuclein (αSyn) RT-QuIC seeding amplification assay (SAA) on cerebrospinal fluid (CSF) and tenfold serially diluted brain homogenates from different brain areas in rpDLB patients and typical long-lasting Lewy body disease (LBD) with dementia patients as control group.ResultsRpDLB patients were older (p = 0.047) and presented more cognitive fluctuations (p = 0.005), visual hallucinations (p = 0.020), neuropsychiatric symptoms (p = 0.006) and seizures (p = 0.032), and fewer cerebellar (p < 0.001) and visual (p = 0.004) signs than CJD ones. Delirium onset was more common than in both CJD (p < 0.001) and rpAD (p = 0.008). Atypical LBD signs (pyramidal, myoclonus, akinetic mutism) were common. All tested patients were positive by CSF αSyn SAA. Concomitant pathologies were common, with only four cases showing relatively “pure” LBP. LBP load and αSyn seeding activity measured through αSyn RT-QuIC SAA were not significantly different between rpDLB patients and typical LBD. We found a likely pathogenic variant in GBA in one patient.ConclusionsOur results indicate that: 1) rpDLB exhibits a distinct clinical signature (2) CSF αSyn SAA is a reliable diagnostic test; 3) rpDLB is a heterogeneous neuropathological entity that can be underlain by both widespread pure LBP, or multiple copathologies 4) rpDLB is likely not sustained by distinct αSyn conformational strains; 5) genetic defects may, at least occasionally, contribute to the poor prognosis in these patients.

Eccrine hidrocystomas: A distinct clinicopathologic entity and a potential mimicker of malignancy—A case series with a review of the literature

Abstract Purpose: Eccrine hidrocystomas are a rare, benign cystic lesion of the skin primarily found in the head and neck region, with a predilection for the periorbital area in adult females. These cysts typically present as small, tense, thin-walled structures ranging from 1 to 6 mm in size, occurring either as solitary entities or in multiples. Despite their benign nature, eccrine hidrocystomas pose diagnostic challenges due to their resemblance to malignant lesions both clinically and in imaging studies. This study aims to explore the varied clinical presentations of eccrine hidrocystoma and discuss the complexities associated with its diagnosis. Materials and Methods: Five cases were included in the study along with a comprehensive review of the existing literature. We emphasize the importance of accurate and early diagnosis for appropriate management. The clinical manifestations of eccrine hidrocystoma often overlap with features suggestive of malignancy, underscoring the necessity for meticulous histopathological examination to definitively differentiate between these entities. This differentiation is crucial as it impacts treatment decisions and patient outcomes. Conclusion: In conclusion, our study underscores the diagnostic dilemmas posed by eccrine hidrocystoma, highlights its potential mimicry of malignancy, and emphasizes the significance of histopathological evaluation in achieving accurate diagnosis and guiding management strategies.

A Prospective Study of Patients Presenting With Pre-sternal Keloids.

Keloid represents a pathological form of scarring. They are very common in the anterior chest area; nearly 50% of all keloids occur in this location. One of the reasons for this is that folliculitis and acne, known for triggering the development of keloids, are common on the anterior chest. The other reason is the tension load in this area due to the frequent movements of the upper limbs and the respiratory movements. These movements stretch the skin of the anterior chest horizontally. When this cyclical tension is imposed on the anterior chest wounds, there is an exacerbation and prolongation of the inflammation in the reticular dermis of the wound. These stresses induce the growth of keloids along the prevailing lines of skin tension. We performed a prospective study in which patients were recruited over a period of one year. Patients presenting with symptomatic pre-sternal keloids and requesting treatment but were unwilling to undergo surgical intervention were included in this study. Patients with a history of previous thoracic surgery were excluded. Baseline assessment and documentation of the lesion were performed. The study patients received three sessions of intralesional injections of a combination of triamcinolone acetonide and hyaluronidase at four weekly intervals. The final assessment was performed four weeks after the third session. The study included 47 lesions in 47 patients with ages of the patients ranging from 16 to 70 years. Pre-sternal keloids were found to be more common among males than females, with a male-to-female ratio of 2.35:1. Patients presented with pre-sternal keloids that had been present for varying periods ranging from three to 81 months. All of our 47 patients completed the three sessions of the treatment. Following the treatment, there was an improvement in the patient's symptoms, as evidenced by the reduction in the mean pruritis scores and pain scores. There was an overall reduction in the size of the lesion. The decrease in the height of the lesions was more evident than the reduction in the craniocaudal or transverse dimensions of the lesions. There were improvements in Vancouver Scar Scale(VSS) vascularity scores and pliability scores following the treatment. We conclude that pre-sternal keloids should be considered as a distinct clinico-pathological entity. There are differences with regard to pathogenesis, clinical presentation, and management when compared to keloids elsewhere. Treatment with intralesional injections of a combination of triamcinolone acetonide and hyaluronidase effectively relieves the symptoms and may be considered in patients not willing to undergo surgical intervention. Recurrences can occur and need further treatments.

TAFRO Syndrome: A Syndrome or a Subtype of Multicentric Castleman Disease?

TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis of bone marrow/renal dysfunction, organomegaly) syndrome is a systemic inflammatory disorder of unknown etiology. It has been recognized as a subtype of idiopathic multicentric Castleman disease (iMCD), and the international diagnostic criteria for iMCD-TAFRO require a lymph node histopathology consistent with iMCD. Furthermore, TAFRO syndrome is defined as a heterogeneous clinical entity caused by underlying diseases such as malignancy, autoimmune diseases, or infections. However, the cases that led to the proposal of TAFRO syndrome lacked recognizable lymphadenopathy and were inconsistent with any other diseases, despite vigorous efforts in differential diagnosis. Irrespective of the presence or absence of Castleman disease (CD)-like histology, TAFRO syndrome exhibits homogeneous clinical, laboratory, and prognostic features, setting it apart from iMCD without TAFRO syndrome. Defining iMCD-TAFRO apart from TAFRO syndrome is deemed meaningless and confusing. MCD is a heterogeneous lymphoproliferative disorder consisting of several subtypes with different pathogenesis, clinical manifestations, and histological features. Typical MCD in Japan, characterized by the histology of plasma cell type and marked polyclonal hypergammaglobulinemia, is identical to idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia (IPL). Although IPL is classified into iMCD-NOS (not otherwise specified), it should be recognized as a distinct clinicopathological entity. Furthermore, we propose to separate TAFRO syndrome from the MCD category as a defined disorder.

Case report of rare gastrointestinal non-Hodgkin's lymphoma presenting as intussusception in adults

Gastrointestinal lymphomas comprise a group of distinct clinicopathological entities of B- or T- cell type, with primary gastrointestinal Hodgkin’s lymphoma being extremely uncommon. The gastrointestinal tract is the predominant site of extra-nodal non-Hodgkin's lymphoma accounting for 30-40% of all extra- nodal lymphomas.1 Most common non-Hodgkin’s lymphoma causing intussusception is diffuse large B-cell lymphoma (DLBCL). We herein report a rare case of ileo-colic Intussusception due to diffuse large B-cell lymphoma in a 42-year-old female. Computed tomography showed ileo-colic intussusception. Open hemicolectomy with ileo-colic anastomosis was done with postoperative chemotherapy.

Thoracic SMARCA4-deficient tumors: a clinicopathological analysis of 52 cases with SMARCA4-deficient non-small cell lung cancer and 20 cases with thoracic SMARCA4-deficient undifferentiated tumor.

Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a distinct clinicopathological entity with an aggressive clinical course. Additionally, SMARCA4/BRG1 deficiency can be observed in a few patients with non-small cell lung cancer (NSCLC). We aimed to compare the clinicopathological, immunohistochemical and prognostic features of SMARCA4-deficient NSCLC (SMARCA4-dNSCLC) with those of thoracic SMARCA4-UT. Patients with BRG1-deficient tumors in the lung or thorax were enrolled in the study from the Department of Pathology of West China Hospital, Sichuan University, from January 2014 to June 2022. We retrospectively collected the clinicopathological and immunohistochemical features and outcomes of these patients. Seventy-two patients had tumors in the lung or thorax with BRG1-deficient expression, including 52 patients with SMARCA4-dNSCLC and 20 patients with thoracic SMARCA4-UT. Among the patients with SMARCA4-dNSCLC, 98.1% were male, 85.7% were smokers, and 79.5% (35/44) had tumor-node-metas-tasis (TNM) III-IV tumors. Among the patients with thoracic SMARCA4-UT, all were males who smoked, and 93.75% (15/16) had TNM III-IV tumors. Pure solid architecture and necrosis were the predominant pathological features. Rhabdoid morphology was observed in some SMARCA4-dNSCLCs (10/52, 19.2%) and thoracic SMARCA4-UTs (11/20, 55%). In most patients with thoracic SMARCA4-UT, the tumors exhibited scattered weak expression or negative expression of epithelial markers, and positive expression of CD34 and Syn. Overall survival (OS) and progression-free survival (PFS) were not significantly different between patients with SMARCA4-dNSCLC and patients with thoracic SMARCA4-UT (p = 0.63 and p = 0.20, respectively). Thoracic SMARCA4-DTs include SMARCA4-dNSCLC and thoracic SMARCA4-UT. Both have overlapping clinicopathological features and poor prognosis. We hypothesize that thoracic SMARCA4-UT may be the undifferentiated or dedifferentiated form of SMARCA4-dNSCLC. However, further studies with larger cohorts and longer follow-up periods are needed.

Thoracic SMARCA4-deficient undifferentiated tumor: A clinicopathological and prognostic analysis of 35 cases and immunotherapy efficacy

BackgroundThoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a recently recognized distinct clinicopathological entity according to the fifth edition of the 2021 World Health Organization Classification (WHO) for thoracic tumors. Thoracic SMARCA4-UTs are diagnostically challenging to diagnose, especially on small biopsies. MethodsWe identified 35 thoracic SMARCA4-UTs from the Department of Pathology of West China Hospital, Sichuan University, between January 2017 and December 2022. In the present study, we summarized the clinicopathological features, prognostic significance and immunotherapy efficacy of thoracic SMARCA4-UTs. ResultsAll 35 patients were male, and 88.6 % were smokers. The left upper lobe (25.7 %) and mediastinum (20.0 %) were the most affected sites. 17.1 % of the patients received surgical treatment. 30.4 % of the patients were stage III, and 69.6 % were stage IV. Solid architecture (100 %), rhabdoid morphology (51.4 %) and necrosis (42.9 %) were the common histological features. Immunohistochemical staining revealed CD34 and synaptophysin positivity in most patients (76.9 % and 65.2 %, respectively). Patients had unfavorable outcomes. Patients who received immunotherapy had better OS and PFS than those who did not (p = 0.007 and p = 0.02, respectively). Five patients were evaluated for immunotherapy efficacy, and four of those patients were negative expression of PD-L1. Cases 1–4 presented TIL counts ranging from 20 to 1000/HPF. Case 5 presented TIL counts of 5–10/HPF. Mutations in SMARCA4 were confirmed in cases 4 and 5, and the TMB was 5.98 and 5.03 mutations/Mb, respectively. Case 1 achieved a CR, cases 2–4 achieved a PR, and case 5 had a PD. Five patients who received immunotherapy were all alive, with OS ranging from 10.7 to 33.6 months. ConclusionsThoracic SMARCA4-UTs exhibited an aggressive clinical course, presented solid architecture with or without necrosis and/or rhabdoid morphology, and frequently expressed CD34 and synaptophysin. Some thoracic SMARCA4-UTs appear to be associated with responsiveness to immunotherapy, suggesting the need for validation in larger series.

Desmoplastic small round cell tumor a case report of a rare intra-abdominal tumor of the young adult

Desmoplastic small round cell tumor is a rare and highly aggressive mesenchymal tumor described as a distinct clinico-pathological entity in 1989 by Gerald . These tumors occur mainly in the peritoneal cavity,although other primary sites, such as testicular, ovarian, thoracic, pulmonary, intracranial and head and neck regions have been reported. Clinical symptoms are non-specific. Diagnosis is based on histological analysis combined with immunohistochemical study. Histological study typically shows small round blue cells in nests separated by abundant desmoplastic stroma associated with a single chromosomal translocation t(11:22) (p 13; q 12) involving the EWSR1 and WT1 genes. The prognosis is particularly poor, with median survival ranging from 17 to 25 months. Management of this tumor remains difficult, and current regimens do not achieve a significant cure rate despite the use of aggressive treatments such as polychemotherapy.

Primary cutaneous CD30+ lymphoproliferative disorders with DUSP22 translocation.

Primary cutaneous CD30+ lymphoproliferative disorders (LPD) encompass abroad category of clonal Tcell proliferations with varied clinical presentations. Classically, lymphomatoid papulosis (LyP) and primary cutaneous anaplastic large cell lymphoma (ALCL) have been recognized as distinct clinicopathological entities according to their differing clinical features. Recently, asubset of LyP and both cutaneous and systemic ALCL have been shown to carry aDUSP22 translocation [1-3], adefining molecular feature for the novel entity "LyP with DUSP22t" [1]. In cutaneous biopsies, both primary cutaneous DUSP22-translocated ALCL and LyP with DUSP22 rearrangements are characterized by abiphasic pattern with significant small cell epidermotropism. Adistinct protein expression profile with preserved T Cell Receptor (TCR) expression, positivity for CD30, LEF1, HLA, and CD58, and negativity for cytotoxic marker expression as well as phospho-STAT3 protein is consistently found in these cases.

Multicentric Hyaline-Vascular Castleman Disease: The Missing Link?

Introduction: Castleman disease (CD) is a rare lymphoproliferative disorder that encompasses distinct clinicopathological entities. Unicentric form of the disease (UCD) usually involves a single lymph node station, exhibits hyaline vascular (HV) pathological changes with follicular dendritic cell expansion, and may associate with specific and life-threatening complications including paraneoplastic pemphigus (PNP) and follicular dendritic cell sarcoma (FDCS). Plasma cell interfollicular infiltration is absent in the HV subtype as opposed to the Plasma-Cell (PC) or Mixed subtypes. PC subtype has been associated with inflammatory symptoms thought to be secondary to plasma cell infiltration and represents the majority of HHV8-negative “idiopathic” multicentric forms of the disease. Interestingly, patients with PC-UCD behave as PC-MCD, suggesting a stronger role of histology rather than Unicentric vs Multicentric phenotype in disease expression. We here studied the phenotype of HV-MCD, a rare subtype of CD characterized by hyaline-vascular pathological changes involving 2 or more lymph node stations. Methods: Patients were screened through the French national reference center for CD between January 1994 and June 2023. Cases were followed from first symptoms to last follow-up visit. Comparators consisted of patients with HV-UCD and patients with PC/Mixed iMCD (P/M-iMCD). All cases and biopsies were reviewed by three expert clinicians and one expert pathologist. Results: Sixteen patients with a diagnosis of HHV8-negative HV-MCD were identified. All patients had supra- and infradiaphragmatic involvement. Four were excluded because of a subsequent diagnosis of POEMS, systemic lupus erythematosus, tuberculosis, or inborn error of immunity. The 12 remaining patients were considered as having HV-iMCD and compared to 101 patients with P/M-iMCD and 139 patients with HV-UCD. Characteristics and comparison between the 3 groups are depicted in Table 1. When compared to HV-UCD, HV-iMCD displayed frequent systemic involvement with significantly higher ECOG, higher frequency of fever and splenomegaly, and higher levels of C-reactive protein, gammaglobulins, leukocytes and ferritinemia ( Figure 1). Age at diagnosis was not different between HV-UCD and HV-iMCD. No cases of TAFRO syndrome were observed in HV-UCD whereas 4 cases were observed in HV-iMCD. All cases of PNP (n=12) and FDCS (n=3) were observed in the HV-UCD group. We observed a younger age at diagnosis in HV-iMCD compared to P/M-iMCD (median 24 [range 13-70] vs median 50 [range 11-88] years respectively, p = 0.01). We also noted a trend towards lower levels of C reactive protein and gammaglobulins as well a higher albumin level in HV-iMCD vs P/M-iMCD but these differences were not significant ( Figure 1 and Table 1). Treatments were similar between HV-iMCD and P/M-iMCD with prescription of steroids or anti-IL6R as first line therapy in 8/12 (67%) and 61/101 (60%) respectively. As expected, surgery was the first line therapy in 98/139 (72%) of HV-UCD patients. One patient with HV-iMCD and two with HV-UCD died (logrank p = 0.10), whereas 13 died in the P/M-iMCD group (logrank p = 0.8). Conclusions: These data altogether indicate that HV-iMCD appears to be a distinct entity in CD landscape, sharing pathological aspects of HV-UCD and clinical/biological features of P/M iMCD. In line with this view, there seems to be no overlap between HV-UCD and HV-iMCD-related complications. The findings also suggest that nodal PC infiltration is not sufficient to explain the inflammatory pattern of iMCD.

Sarcoidosis-associated pulmonary fibrosis: joining the dots.

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. A minority of patients with sarcoidosis develop sarcoidosis-associated pulmonary fibrosis (SAPF), which may become progressive. Genetic profiles differ between patients with progressive and self-limiting disease. The mechanisms of fibrosis in SAPF are not fully understood, but SAPF is likely a distinct clinicopathological entity, rather than a continuum of acute inflammatory sarcoidosis. Risk factors for the development of SAPF have been identified; however, at present, it is not possible to make a robust prediction of risk for an individual patient. The bulk of fibrotic abnormalities in SAPF are located in the upper and middle zones of the lungs. A greater extent of SAPF on imaging is associated with a worse prognosis. Patients with SAPF are typically treated with corticosteroids, second-line agents such as methotrexate or azathioprine, or third-line agents such as tumour necrosis factor inhibitors. The antifibrotic drug nintedanib is an approved treatment for slowing the decline in lung function in patients with progressive fibrosing interstitial lung diseases, but more evidence is needed to assess its efficacy in SAPF. The management of patients with SAPF should include the identification and treatment of complications such as bronchiectasis and pulmonary hypertension. Further research is needed into the mechanisms underlying SAPF and biomarkers that predict its clinical course.

Advances in Immunotherapy for the Treatment of Cutaneous T-Cell Lymphoma.

Cutaneous T-Cell Lymphoma (CTCL) is a heterogenous disease that consists of distinct clinicopathologic entities and presentations requiring a unique and expert approach to management. The most common subtype is mycosis fungoides, in which local disease has an excellent prognosis and is often managed with topical therapy alone. More extensive cutaneous involvement as well as involvement of lymph nodes and the peripheral blood (Sezary syndrome) require systemic therapies. Recent years have brought an expansion of therapeutic options, specifically with immune-based approaches that were developed using the knowledge gained regarding the biology and molecular pathology of CTCL. Previous systemic therapies such as retinoids, histone deacetylase inhibitors, and chemotherapeutic agents come with significant toxicity and only short-term response. Newer agents such as mogamulizumab and brentuximab vedotin use a targeted immune-based approach leading to longer periods of response with less systemic toxicity. While still in its infancy, the use of immune checkpoint inhibitors such as nivolumab and pembrolizumab appears promising, and while their current clinical application is limited, early data suggest possible future areas for research of immune manipulation to treat CTCL. Herein, we review these novel immune-based treatment strategies, their superiority over prior systemic options, and the ongoing need for further research and clinical trial enrollment.

Improved survival for dose-intensive chemotherapy in primary mediastinal B-cell lymphoma: a systematic review and meta-analysis of 4,068 patients.

Primary mediastinal B-cell lymphoma (PMBCL) is a distinct clinicopathologic entity. Currently, there is a paucity of randomized prospective data to inform on optimal front-line chemoimmunotherapy (CIT) and use of consolidative mediastinal radiation (RT). To assess if distinct CIT approaches are associated with disparate survival outcomes, we performed a systematic review and meta-analysis comparing dose-intensive (DI-CIT) versus standard CIT for the front-line treatment of PMBCL. Standard approach (S-CIT) was defined as R-CHOP-21/CHOP-21, with or without RT. DI-CIT were defined as regimens with increased frequency, dose, and/or number of systemic agents. We reviewed data on 4,068 patients (2,517 DI-CIT; 1,551 S-CIT) with a new diagnosis of PMBCL. Overall survival for DI-CIT patients was 88% (95% CI: 85-90) compared to 80% for the S-CIT cohort (95% CI: 74-85). Meta-regression revealed an 8% overall survival (OS) benefit for the DI-CIT group (P<0.01). Survival benefit was maintained when analyzing rituximab only regimens; OS was 91% (95% CI: 89-93) for the rituximab-DI-CIT arm compared to 86% (95% CI: 82-89) for the R-CHOP-21 arm (P=0.03). Importantly, 55% (95% CI: 43-65) of the S-CIT group received RT compared to 22% (95% CI: 15-31) of DI-CIT patients (meta-regression P<0.01). To our knowledge, this is the largest meta-analysis reporting efficacy outcomes for the front-line treatment of PMBCL. DI-CIT demonstrates a survival benefit, with significantly less radiation exposure, curtailing long-term toxicities associated with radiotherapy. As we await results of randomized prospective trials, our study supports the use of dose-intensive chemoimmunotherapy for the treatment of PMBCL.

Endometriosis in clear cell and endometrioid carcinoma ovary: its impact on clinicopathological characteristics and survival outcomes.

Malignant transformation in endometriosis was first described by Sampson in 1925. There is now sufficient evidence of its association specifically with endometrioid (EOC) and clear cell ovarian cancer (CCOC). Whether endometriosis-associated ovarian cancer (EAOC) is a distinct clinicopathological entity from non-endometriosis-associated ovarian cancer (NEAOC) remains uncertain. This study aimed to assess the impact of endometriosis on clinical characteristics and survival outcomes in EOC and CCOC. This is a retrospective single-institution analysis of patients diagnosed with CCOC AND EOC between 2010 and 2021. Demographic and clinical presentation data were obtained from medical records. Patients were followed up till March 2023. Statistical analysis was done using the IBM SPSS Statistics 20 Windows. Of the 77 cases of CCOC and EOC ovary, 38 had histopathologically proven endometriosis. There was no difference in age (51.62 and 50.05 years, respectively), body mass index, parity, menopausal status and CA 125 levels at presentation. Ascites was more frequent in the absence of endometriosis (30% versus 8.1%, p = 0.015). However, this did not translate to a statistical difference in the stage, with the majority presenting in the early stage. (94% versus 83%). All 78 patients underwent primary cytoreduction with equal rates of optimal resection.There was no difference in the mean disease-free interval between EAOC and NEAOC (107.6 and 109.4 months, p 0.484). Recurrences were predominantly pelvic in both groups. The disease-specific survival was 111.7 and 120.1 months, respectively, with and without endometriosis. This was however not statistically significant (p 0.751). In the Indian population, endometriosis did not have any impact on the age at presentation, CA 125 levels, stage of the disease and survival outcomes in EOC and CCOC ovary.

Integrated genetic analyses of immunodeficiency-associated Epstein-Barr virus- (EBV) positive primary CNS lymphomas.

Immunodeficiency-associated primary CNS lymphoma (PCNSL) represents a distinct clinicopathological entity, which is typically Epstein-Barr virus-positive (EBV+) and carries an inferior prognosis. Genetic alterations that characterize EBV-related CNS lymphomagenesis remain unclear precluding molecular classification and targeted therapies. In this study, a comprehensive genetic analysis of 22 EBV+PCNSL, therefore, integrated clinical and pathological information with exome and RNA sequencing (RNASeq) data. EBV+PCNSL with germline controls carried a median of 55 protein-coding single nucleotide variants (SNVs; range 24-217) and 2 insertions/deletions (range 0-22). Genetic landscape was largely shaped by aberrant somatic hypermutation with a median of 41.01% (range 31.79-53.49%) of SNVs mapping to its target motifs. Tumors lacked established SNVs (MYD88, CD79B, PIM1) and copy number variants (CDKN2A, HLA loss) driving EBV-PCNSL. Instead, EBV+PCNSL were characterized by SOCS1 mutations (26%), predicted to disinhibit JAK/STAT signaling, and mutually exclusive gain-of-function NOTCH pathway SNVs (26%). Copy number gains were enriched on 11q23.3, a locus directly targeted for chromosomal aberrations by EBV, that includes SIK3 known to protect from cytotoxic T-cell responses. Losses covered 5q31.2 (STING), critical for sensing viral DNA, and 17q11 (NF1). Unsupervised clustering of RNASeq data revealed two distinct transcriptional groups, that shared strong expression of CD70 and IL1R2, previously linked to tolerogenic tumor microenvironments. Correspondingly, deconvolution of bulk RNASeq data revealed elevated M2-macrophage, T-regulatory cell, mast cell and monocyte fractions in EBV+PCNSL. In addition to novel insights into the pathobiology of EBV+PCNSL, the data provide the rationale for the exploration of targeted therapies including JAK-, NOTCH- and CD70-directed approaches.

The KAT6B::KANSL1 Fusion Defines a New Uterine Sarcoma With Hybrid Endometrial Stromal Tumor and Smooth Muscle Tumor Features

Neoplasms harboring a KAT6B/A::KANSL1 fusion were initially reported as benign (leiomyomas) and malignant (leiomyosarcomas, low-grade endometrial stromal sarcomas [LG-ESSs]) uterine neoplasms. However, they may represent an emerging entity characterized by clinical aggressiveness contrasting with a rather reassuring microscopic appearance. Here, we aimed to confirm that this neoplasm is a distinct clinicopathologic and molecular sarcoma and identify criteria that should alert pathologists and lead to KAT6B/A::KANSL1 fusion testing in routine practice. Therefore, we conducted a comprehensive clinical, histopathologic, immunohistochemical, and molecular study, including array comparative genomic hybridization, whole RNA-sequencing, unsupervised clustering, and cDNA mutational profile analyses of 16 tumors with KAT6B::KANSL1 fusion from 12 patients. At presentation, patients were peri-menopausal (median, 47.5 years), and the primary tumors were located in the uterine corpus (12/12, 100%), with an additional prevesical location in 1 (8.3%) of 12 cases. The relapse rate was 33.3% (3/9). All tumors (16/16, 100%) showed morphologic and immunohistochemical features overlapping between leiomyoma and endometrial stromal tumors. A whirling recurrent architecture (resembling fibromyxoid-ESS/fibrosarcoma) was found in 13 (81.3%) of 16 tumors. All tumors (16/16, 100%) exhibited numerous arterioliform vessels, and 13 (81.3%) of 18 had large hyalinized central vessels and collagen deposits. Estrogen and progesterone receptors were expressed in 16 (100%) of 16 and 14 (87.5%) of 16 tumors, respectively. Array comparative genomic hybridization performed on 10 tumors classified these neoplasms as simple genomic sarcomas. Whole RNA-sequencing on 16 samples and clustering analysis on primary tumors found that the KAT6B::KANSL1 fusion always occurred between exons 3 of KAT6B and 11 of KANSL1; no pathogenic variant was identified on cDNA, all neoplasms clustered together, close to LG-ESS, and pathway enrichment analysis showed cell proliferation and immune infiltrate recruitment pathway involvement. These results confirm that the sarcomas harboring a KAT6B/A::KANSL1 fusion represent a distinct clinicopathologic entity, close to LG-ESS but different, with clinical aggressiveness despite a reassuring morphology, for which the KAT6B/A::KANSL1 fusion is the molecular driver alteration.

Dendritic Melanocytic Hyperplasia in Pterygia: A Potential Source of Diagnostic Confusion with Primary Acquired Melanosis

Introduction: The aim of this study was to report the nearly ubiquitous prevalence of melanocytic hyperplasia in benign pterygia/pingueculae and establish that the entity is insufficiently recognized. Methods: This is a retrospective immunohistochemical pathology case series of 30 consecutive pterygia/pingueculae samples selected from an ophthalmic pathology database at a single institution. Histopathologic and immunohistochemistry analyses with anti-SOX-10 and anti-MART-1 antibodies were used for identifying melanocytes. The number of squamous cells intervening between melanocytes was determined. Results: The frequency of dendritic melanocytes was found to meet the criteria for dendritic melanocytic hyperplasia in 29 of 30 pterygia/pingueculae samples using specific antibodies. Melanocytes were found in several patterns: diffuse (28%), multifocal (28%), and focal (44%). In each case, the melanocytes were distributed as single melanocytes at the base; clusters of melanocytes were seen in 17% of samples. There were an average of about two intervening epithelial cells between melanocytes at the base. Conclusion: When diagnosed with immunohistochemistry, dendritic melanocytic hyperplasia is nearly ubiquitous in pterygia and pingueculae. Melanocytic hyperplasia may have a distribution that includes nests and single melanocytes above the basal layer, which can be confused with forms of primary acquired melanosis. It is important for pathologists to recognize these lesions as a distinct benign clinicopathologic entity.

Molecular Mechanisms of Gastrointestinal Stromal Tumors and Their Impact on Systemic Therapy Decision.

Gastrointestinal stromal tumors (GISTs) are soft tissue sarcomas that mostly derive from Cajal cell precursors. They are by far the most common soft tissue sarcomas. Clinically, they present as gastrointestinal malignancies, most often with bleeding, pain, or intestinal obstruction. They are identified using characteristic immunohistochemical staining for CD117 and DOG1. Improved understanding of the molecular biology of these tumors and identification of oncogenic drivers have altered the systemic treatment of primarily disseminated disease, which is becoming increasingly complex. Gain-of-function mutations in KIT or PDGFRA genes represent the driving mutations in more than 90% of all GISTs. These patients exhibit good responses to targeted therapy with tyrosine kinase inhibitors (TKIs). Gastrointestinal stromal tumors lacking the KIT/PDGFRA mutations, however, represent distinct clinico-pathological entities with diverse molecular mechanisms of oncogenesis. In these patients, therapy with TKIs is hardly ever as effective as for KIT/PDGFRA-mutated GISTs. This review provides an outline of current diagnostics aimed at identifying clinically relevant driver alterations and a comprehensive summary of current treatments with targeted therapies for patients with GISTs in both adjuvant and metastatic settings. The role of molecular testing and the selection of the optimal targeted therapy according to the identified oncogenic driver are reviewed and some future directions are proposed.