Lack of CD 29 (beta1 integrin) and CD 54 (ICAM-1) adhesion molecules in intravascular lymphomatosis

A Rare Case of Intravascular Large B-cell Lymphoma Presenting as Fever of Unknown Origin With Unexplained Proteinuria

Intravascular large B-cell lymphoma (IVLBCL) is a subtype of extranodal diffuse large B-cell lymphoma, characterized by neoplastic B-cell proliferation within blood vessels. Its nonspecific presentation, often as fever of unknown origin (FUO) and systemic symptoms, makes diagnosis challenging. We report the case of a 66-year-old male patient presenting with persistent fever, weight loss, and respiratory failure. Initial investigations, including bone marrow biopsy and imaging, were inconclusive. The lack of response to empirical therapy and the patient's worsening condition presented us with a diagnostic dilemma. The unexplained proteinuria led us to perform a renal biopsy, which confirmed IVLBCL through the identification of atypical B-cells in glomerular capillaries. This case highlights the importance of considering IVLBCL in persistent FUO cases and the role of specific tissue biopsy in diagnosis, even with nonspecific bone marrow studies. Early detection and prompt treatment are crucial, but prognosis remains poor due to diagnostic delays.

The utility of the normal thin section skin biopsy in the assessment of systemic/extracutaneous disease and small fiber neuropathy

Diseases reflective of multiorgan vascular injury of diverse etiology, peripheral nerve disease, dysautonomia syndromes, and intravascular lymphoma may exhibit abnormalities on a normal skin biopsy that may be instrumental in establishing a diagnosis. A retrospective review of our database was conducted to uncover cases where a normal skin biopsy was performed to rule in or out such systemic diseases as complement-driven thrombotic microvascular disease (including atypical hemolytic uremic syndrome, posttransplant thrombotic microangiopathy, and severe or critical COVID-19), systemic capillary leak syndrome, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) intravascular B cell lymphoma, small fiber neuropathy, dysautonomia syndromes, and mast cell activation syndrome. Among the special studies were immunohistochemical staining to detect C5b-9, CD56, and myxovirus resistance protein A, as well as mast cell, B and T cell markers. Characteristic patterns were critical in establishing diagnoses such as : increased C5b-9 microvascular deposition in the deltoid area (atypical hemolytic uremic syndrome, posttransplant thrombotic microangiopathy, catastrophic antiphospholipid antibody syndrome, and severe or critical COVID-19); enhanced type I interferon signaling (systemic capillary leak syndrome); ultrastructural arteriopathic changes (CADASIL); reduced cutaneous autonomic innervation in the lower extremities (small fiber neuropathy and postural orthostatic tachycardia syndrome); presence of intravascular lymphocytes on biopsy of abdominal, thigh, and buttock skin (intravascular B cell lymphoma); and a higher than normal density of mast cells in the absence of other inflammatory cell types (mast cell activation syndrome). The skin is clearly a critical window for understanding extracutaneous disease, a concept well exemplified by the myriad of diseases suggested by the microscopic and/or ultrastructural examination of clinically normal skin and therefore establishing the normal skin biopsy as an important tool for understanding certain extracutaneous reactive, neoplastic and paraneoplastic syndromes as well as small fiber neuropathy.

Intravascular Large B-cell Lymphoma in a Young Southeast Asian Male With Recurrent Strokes and Pulmonary Ground Glass Opacities With a Normal Chest Radiograph

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of extranodal large B-cell lymphoma characterized by the growth of lymphoma cells within lumina of blood vessels, especially capillaries, which aggregate to form clots, resulting in organ ischemia. In Caucasians, it predominantly involves the central nervous system (CNS) and the skin, with the cutaneous variant carrying a better prognosis. Whereas in Asians it preferentially involves the bone marrow, liver, and spleen and is associated with hemophagocytic syndrome. We report a case of a young Asian male with neurological, pulmonary, and hepatosplenic involvement. He presented with recurrent strokes, chronic cough, and unintentional weight loss. The chest radiograph (CXR) on admission was clear. Magnetic resonance imaging (MRI) of the brain showed acute multifocal infarcts, and a whole-body computed tomography (CT) scan revealed upper-lobe predominant pulmonary ground glass opacities (GGOs) with mediastinal lymphadenopathy. Interestingly, a CXR performed one week after the CT scan remained clear. The positron emission tomography-computed tomography (PET-CT) showed hepatosplenic and adrenal involvement. The diagnosis was confirmed via a bronchoscopic approach. The patient received chemotherapy consisting of MR-CHOP (methotrexate, rituximab, cyclophosphamide, adriamycin, vincristine, and prednisolone), high-dose methotrexate, and intrathecal cytarabine, which led to complete remission. Subsequently, he underwent an autologous peripheral blood stem cell transplant. At the time of writing this case report, the patient is still in complete remission for three years after the initial diagnosis. As IVLBCL has a non-specific clinicoradiological presentation, it is important to suspect IVLBCL in patients with an atypical neurological and pulmonary presentation in the presence of raised serum lactate dehydrogenase (LDH) and to consider a CT scan of the thorax if CXR is normal.

EBV-Positive Intravascular Large B-Cell Lymphoma of the Small Intestine: A Case Report and Literature Review

Intravascular large B-cell lymphoma (IVLBCL) is a rare lymphoma that affects the brain, skin, and bone marrow. We describe the case of a 75-year-old man who was admitted to the hospital after 4 h of stomach aches. A thorough physical examination indicated stomach discomfort and skin discoloration. Laboratory tests revealed thrombocytopenia and elevated lactate dehydrogenase levels. A computed tomography scan of the abdomen revealed that the small intestine wall was thickened, edematous, and necrotic. The necrotic small bowel was surgically removed, revealing many little round, homogenous, and unusual cells in the mesenteric vein. In-situ hybridization revealed that these cells were positive for PAX5, CD20, CD79a, CD10, and BCL2, as well as Epstein-Barr virus-encoded small RNA. After 1 week of hospitalization without treatment, the patient was diagnosed with IVLBCL and died of multiple organ dysfunction syndrome. IVLBCL is a rare illness that affects the small intestine and possibly the gastrointestinal system. It has an insidious start, a fast development, and a dismal prognosis. Knowing its clinicopathologic traits helps in understanding the illness, making an early diagnosis, and preventing rapid worsening.

The natural history of neurolymphomatosis

BACKGROUND

Neurolymphomatosis is a lymphoid malignancy of the peripheral nervous system and its natural history is poorly understood.

METHODS

We performed PubMed search and extracted clinical data for Kaplan-Meier statistics to determine outcome parameters over time. Kruskal-Wallis test was performed to compare prognostic factors.

RESULTS

Our search identified 559 patients and their median age was 61 years. Median overall survival (OS) was 12.0 (range 10.0-15.0) months. Diffuse large B-cell lymphoma was the most frequent histology, involving the brachial plexus, cranial nerves, and sciatic nerve. None had molecular profiling. There was a progressive lengthening of OS in successive decades, from 0.5 (95% CI 0.0-0.8) to 26.4 (95% CI 18.0-34.8) months between 1951 and 2022 (r2 = 0.0528, p < 0.00001). Time from first treatment (treatment 1) to progression increased from 2.0 to 36.0 (95% CI 6.5-50.7) months (r2 = 0.0961, p = 0.00236). Time from symptom onset to diagnosis remained unchanged (r2 = 0.0000556, p = 0.939). Patients were most frequently treated with methotrexate, rituximab, and/or radiation either alone or in combination. Primary neurolymphomatosis had a better prognosis than secondary neurolymphomatosis. No OS difference was noted between B- and T-cell disease, but low-grade B-cell performed better than Burkitt's lymphoma.

DISCUSSION

Better outcome for patients with neurolymphomatosis is noted over time. But timely diagnosis remains a major problem that needs improvement.

An autopsy case of intravascular large B-cell lymphoma showing a rapid transition to embolic strokes with occlusion of the major cerebral arteries

Intravascular large B-cell lymphoma can induce central nervous system manifestations, including strokes, due to small-vessel occlusion caused by lymphoma cells. However, involvement in large-sized vessels is rare. Here, we present an unusual autopsy case of an 88-year-old man showing a rapid transition from multiple strokes due to small vessel occlusion, typical of intravascular lymphoma, to progressive embolic strokes caused by the occlusion of major cerebral arteries. Magnetic resonance angiography demonstrated the major cerebral arteries associated with those multiple progressive strokes, including the right posterior cerebral artery, left anterior cerebral artery, and right middle cerebral artery, but the detectability was poor. A random skin biopsy at the abdomen confirmed the diagnosis of intravascular large B-cell lymphoma. The patient died 106 days after hospitalization despite intensive treatment. An autopsy revealed broad liquefactive necrosis in the area governed by the major cerebral arteries and multiple small infarctions caused by intravascular lymphoma cells in the small-sized vessels. In addition, the major cerebral arteries showed multiple thromboembolism with partial organization and clusters of intravascular lymphoma cells. Notably, those cells were shown aggregated and attached along the vascular wall of the basilar artery, which might have caused focal hypercoagulation in the near vessels. This aggregation might have disseminated widely in the other major cerebral arteries. Moreover, the cluster of intravascular lymphoma cells in the basilar artery was positive for tumor necrosis factor α, and similar histopathology findings were observed in the splenic veins. However, the pathogenesis of this rare phenomenon involving these cells remains unknown. From a clinical perspective, we should consider the possibility that intravascular lymphoma cells may provoke similar progressive embolic strokes.

Cutaneous Intravascular Hematolymphoid Entities: A Review

Intravascular lymphomas are rare disease conditions that exhibit neoplastic lymphoid cells that are confined mainly to the lumens of small capillaries and medium-sized vessels. The majority of the intravascular lymphomas are of B-cell origin, but they can include NK/T-cell and CD30+ immunophenotypes. In the histologic differential diagnosis are benign proliferations such as intralymphatic histiocytosis and intravascular atypical CD30+ T-cell proliferation. In this review, we discuss the clinical, histopathologic, and molecular findings of intravascular B-cell lymphoma, intravascular NK/T-cell lymphoma, intralymphatic histiocytosis, and benign atypical intravascular CD30+ T-cell proliferation.

Asian variant intravascular large B-cell lymphoma with highly suspected central nervous system involvement: A case report

BACKGROUND

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of extranodal lymphoma. In particular, the Asian variant of IVLBCL is characterized by hemophagocytic lymphohistiocytosis along with bone marrow involvement. However, central nervous system (CNS) involvement is uncommon in this variant compared to the Western variant. Here, we report a case of typical Asian variant IVLBCL with highly suspected CNS involvement and discuss the nature of the disease and its genetic aberration.

CASE SUMMARY

A 67-year-old female patient complained of gradually worsening cognitive impairment. While hospitalized, she developed a high fever and showed marked bicytopenia. Intracranial imaging revealed a suspected leptomeningeal disease. Although no malignant cells were found in the cerebrospinal fluid (CSF), the protein and lactate dehydrogenase levels in CSF were increased. Bone marrow examination revealed an increased number of hemophagocytic histiocytes, and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography with computerized tomography scan revealed increased FDG uptake in both adrenal glands, the liver, and the right ethmoid sinus. A tissue biopsy showed atypical large lymphoid cells with prominent nucleoli in the vessels, and the tumor cells were positive for CD20, BCL2, BCL6, and IRF4/MUM1. In addition, targeted sequencing identified MYD88, TET2, and PIM1 mutations. Consequently, we diagnosed the patient with the Asian variant of IVLBCL with highly suspected CNS involvement.

CONCLUSION

Suspicion of IVLBCL and immediate diagnosis lead to timely treatment. Moreover, careful CNS examination at diagnosis is recommended.

Diagnostic Approach to Pulmonary B-Cell Lymphomas in Small Biopsies, with Practical Recommendations to Avoid Misinterpretation

Pulmonary lymphomas are rare. With the current less invasive approaches used to obtain material for diagnosis, the diagnosis of pulmonary lymphoma is now frequently established in a small biopsy rather than in a resection. Therefore, the diagnosis has become more challenging and requires correlation with the clinico-radiologic presentation and with ancillary studies (immunohistochemistry, flow cytometry, cytogenetics, and/or molecular analysis). Due to the rarity of pulmonary lymphomas, clinical suspicion of a lymphomatous process is low at initial presentation, and material may be only submitted for histopathology. For this reason, herein, we provide recommendations to arrive at the correct diagnosis of the most common lung B-cell lymphomas (marginal zone lymphoma of mucosa-associated lymphoid tissue, diffuse large B-cell lymphoma, intravascular large B-cell lymphoma, lymphomatoid granulomatosis) in the setting of small biopsies, utilizing only immunohistochemistry. The differential diagnosis varies according to the lymphoma subtype and includes reactive conditions, solid tumors, and other hematolymphoid malignancies. Although morphology and immunohistochemistry may be sufficient to establish a diagnosis, in some cases, the best recommendation is to obtain additional tissue via a VATS biopsy/wedge resection with material submitted for flow cytometry, cytogenetics, and/or molecular studies to be able to properly classify a pulmonary lymphoid process.

Intravascular Large B-Cell Lymphoma

Intravascular large B-cell lymphoma (IVBCL) is a very rare and aggressive subtype of extranodal diffuse large B-cell lymphoma (DLBCL) involving the growth of lymphoma cells within blood vessels of all organ types. We present the case of a 55-year-old North-African man with no prior history of neoplastic disease presenting with weight loss and an isolated splenomegaly. Investigations led to the diagnosis of this disease. To the best of our knowledge, this is the first case recorded in Africa. Through this article, we discuss this case and outline the common presentation, paraclinical investigations, and treatment options of IVBCL.

A very rare cause of leukoencephalopathy: Lymphomatosis cerebri

Leukoencephalopathy is a common finding on Magnetic Resonance Imaging (MRI), particularly in the elderly. A differential diagnosis may represent a very bet for clinicians when clear elements for diagnosis are lacking. Diffuse infiltrative "non mass like" leukoencephalopathy on MRI may represent the presentation of a very rare aggressive condition known as lymphomatosis cerebri (LC). The lack of orienting data, such as contrast enhancement on MRI or specific findings on examination of Cerebrospinal Fluid (CSF) or blood tests, may even far more complicate such a difficult diagnosis and orientate toward a less aggressive but time-losing mimic. A 69-old man initially presented to the Emergency Department (ED) complaining the recent appearance of unsteady walking, limitation of down and upgaze palsy, and hypophonia. Brain MRI revealed the presence of multiple, confluent hyperintense lesions on T2/Flair Attenuated Imaging Recovery (FLAIR) sequences involving either the withe matter of the semi-oval centres, juxtacortical structures, basal ganglia, or bilateral dentate nuclei. DWI sequences showed a wide restriction signal in the same brain regions but without any sign of contrast enhancement. Initial 18F-labeled fluoro-2-deoxyglucose positron emission tomography (FDG PET) and CSF studies were not relevant. Brain MRI revealed a high choline-signal, abnormal Choline/ N-Acetyl-Aspartate (NAA), and Choline/Creatine (Cr) ratios, as well as reduced NAA levels. Finally, a brain biopsy revealed the presence of diffuse large B-cell lymphomatosis cerebri. The diagnosis of lymphomatosis cerebri remains elusive. The valorisation of brain imaging may induce clinicians to suspect such a difficult diagnosis and go through the diagnostic algorithm.

Large B-Cell Lymphomas in the 5th Edition of the WHO-Classification of Haematolymphoid Neoplasms-Updated Classification and New Concepts

The family/class of the large B-cell lymphomas (LBCL) in the 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumors (WHO-HAEM5) features only a few major changes as compared to the 4th edition. In most entities, there are only subtle changes, many of them only representing some minor modifications in diagnostic terms. Major changes have been made in the diffuse large B-cell lymphomas (DLBCL)/high-grade B-cell lymphomas (HGBL) associated with MYC and BCL2 and/or BCL6 rearrangements. This category now consists of MYC and BCL2 rearranged cases exclusively, while the MYC/BCL6 double hit lymphomas now constitute genetic subtypes of DLBCL, not otherwise specified (NOS) or of HGBL, NOS. Other major changes are the conceptual merger of lymphomas arising in immune-privileged sites and the description of LBCL arising in the setting of immune dysregulation/deficiency. In addition, novel findings concerning underlying biological mechanisms in the pathogenesis of the different entities are provided.

Cancer-associated spinal cord infarction: A systematic review and analysis of survival predictors

OBJECTIVE

The association between spinal cord infarction (SCI) and cancer is an infrequent condition but requires an accurate diagnosis to establish the appropriate treatment. Clinical features and prognosis of cancer-associated SCI have never been assessed. The aim of this systematic review is to describe the characteristics and outcomes of patients with cancer-associated SCI. Illustratively, a case of ovarian cancer-related SCI is presented.

MATERIAL AND METHODS

Two authors independently analysed three different bibliographic databases looking for cancer-associated SCI case reports and case series. Data regarding age, sex, cardiovascular risk factors (CVRF), history of known cancer, infarction localization, spinal cord syndrome, Zalewski criteria classification, mechanism of ischemia, diagnostic tests, treatment and functional outcome were registered. A statistical analysis was carried out to identify factors related to mortality and survival time.

RESULTS

A total of 48 articles met the inclusion criteria and 52 patients were identified. The median age was 62 years. The most frequent neoplasm was intravascular large B-cell lymphoma. The median survival time was 17.4 weeks and the cumulative probability of survival at 12 months was 16.3%. In the group of deceased patients there was a higher proportion of malignant neoplasms than in those who survived (94.7% vs. 5.3%, p < 0.01). There were no statistically significant differences in terms of mortality or survival time depending on age, previously known cancer or CVRF.

CONCLUSION

Cancer-associated SCI entails a poor outcome. Mortality is increased in patients with malignant neoplasm. No other prognosis factors could be identified.

Characteristics of Renal Intravascular Large B-cell Lymphoma

Introduction

Renal intravascular large B-cell lymphoma (IVLBCL) is a rare, aggressive B-cell lymphoma with neoplastic cells occupying the vascular lumina with only 53 patients reported to date. Here, we present the largest case series to characterize this rare disease.

Methods

We performed a multi-institutional, retrospective review of kidney biopsies and autopsies with a diagnosis of kidney IVLBCL and report our findings.

Results

We identified 20 patients with an average age of 65.7 ± 7.8 years (55% males) with IVLBCL on kidney biopsy. The most common clinical presentation was fever and anemia. Acute kidney injury (AKI) was noted in 70% to 90%, proteinuria in 70% to 84.1%, hematuria in 45%, and nephrotic-range proteinuria in 10% to 26.1% of cases. The median (interquartile range) of serum creatinine was 1.75 (1.14, 3.3) mg/dl. Neoplastic lymphoid cells were present in glomeruli, peritubular capillaries, and arteries or veins. Of the patients, 44.3% showed extrarenal infiltration into bone marrow, liver, spleen, central vervous system, lung and skin. Neoplastic cells express CD20, CD79a, PAX-5, and MUM1+, and were CD10-negative. Available follow-up data showed a median survival of 21 months after diagnosis. Extrarenal involvement is a significant and independent predictor of mortality with a hazard ratio of 4.975 (95% confidence interval:1.38, 17.88) after controlling for age and gender. Serum creatinine, age, sex, and infiltration of intrarenal arteries or veins did not affect survival.

Conclusion

Kidney IVLBCL is a rare disease that is unexpectedly diagnosed by kidney biopsy, presenting with fever, anemia, mild AKI, and proteinuria. Median survival is 21 months and extrarenal involvement is associated with worse outcome.

MRI ischemic and hemorrhagic lesions in arterial and venous territories characterize central nervous system intravascular lymphoma in dogs

Intravascular lymphoma (IVL) is characterized by the proliferation of large malignant lymphocytes within the lumen of blood vessels. This retrospective, multi-center, case series study aimed to describe the MRI features of confirmed central nervous system IVL in dogs and compare them with histopathological findings. Medical record databases from seven veterinary centers were searched for cases of histologically confirmed IVL. Dogs were included if an MRI was performed. The MRI studies and histopathology samples were reviewed to compare the MRI changes with the histopathological findings. Twelve dogs met the inclusion criteria (12 brains and three spinal cords). Imaging of the brains revealed multifocal T2-weighted/FLAIR hyperintense and T1-weighted iso-hypointense lesions, with variable contrast enhancement; areas of abnormal diffusion both in arterial and venous territories in diffusion-weighted imaging; and meningeal enhancement. On gradient echo images (GRE), the changes comprised tubular susceptibility artifacts, consistent with the "susceptibility vessel sign", and additional variably sized/shaped intraparenchymal susceptibility artifacts. Spinal cord lesions presented as fusiform T2-weighted hyperintensities with scattered susceptibility artifacts on GRE and variable parenchymal and meningeal contrast enhancement. On histopathology, subarachnoid hemorrhages and neuroparenchymal areas of edema and necrosis, with or without hemorrhage, indicating ischemic and hemorrhagic infarctions, were found. These lesions were concurrent with severely dilated meningeal and parenchymal arteries and veins plugged by neoplastic lymphocytes and fibrin. Due to the unique angiocentric distribution of IVL, ischemic and hemorrhagic infarcts of variable chronicity affecting both the arterial and venous territories associated with thrombi formation can be detected on MRI.

Intravascular Large B-Cell Lymphoma Genomic Profile Is Characterized by Alterations in Genes Regulating NF-κB and Immune Checkpoints

Intravascular large B-cell lymphoma (IVLBCL) is an uncommon lymphoma with an aggressive clinical course characterized by selective growth of tumor cells within the vessels. Its pathogenesis is still uncertain and there is little information on the underlying genomic alterations. In this study, we performed a clinicopathologic and next-generation sequencing analysis of 15 cases of IVLBCL using a custom panel for the detection of alterations in 68 recurrently mutated genes in B-cell lymphomagenesis. Six patients had evidence of hemophagocytic syndrome. Four patients presented concomitantly a solid malignancy. Tumor cells outside the vessels were observed in 7 cases, 2 with an overt diffuse large B-cell cell lymphoma. In 4 samples, tumor cells infiltrated lymphatic vessel in addition to blood capillaries. Programmed death-ligand 1 (PD-L1) was positive in tumor cells in 4 of 11 evaluable samples and in macrophages intermingled with tumor cells in 8. PD-L1 copy number gains were identified in a higher proportion of cases expressing PD-L1 than in negative tumors. The most frequently mutated gene was PIM1 (9/15, 60%), followed by MYD88L265P and CD79B (8/15, 53% each). In 6 cases, MYD88L265P and CD79B mutations were detected concomitantly. We also identified recurrent mutations in IRF4 , TMEM30A , BTG2 , and ETV6 loci (4/15, 27% each) and novel driver mutations in NOTCH2 , CCND3 , and GNA13 , and an IRF4 translocation in 1 case each. The mutational profile was similar in patients with and without evidence of hemophagocytic syndrome and in cases with or without dissemination of tumor cells outside the vessels. Our results confirm the relevance of mutations in B-cell receptor/nuclear factor-κB signaling and immune escape pathways in IVLBCL and identify novel driver alterations. The similar mutational profile in tumors with extravascular dissemination suggests that these cases may also be considered in the spectrum of IVLBCL.

Intravascular Large B Cell Lymphoma with CNS Involvement Successfully Treated with High-Dose Methotrexate and High-Dose Ara-C Based CNS-Directed Chemoimmunotherapy Alternating with Anthracycline Based Chemoimmunotherapy

Intravascular large B cell lymphoma (IVL) is a rare subtype of diffuse large B cell lymphoma confined to small blood vessels with a predilection for CNS involvement. The prognosis of IVL with CNS involvement (CNS-IVL) is extremely poor. The optimal treatment for CNS-IVL is not well defined. Thus, we report three patients with CNS-IVL successfully treated with a CNS-centric approach consisting of high-dose methotrexate (HDMTX) and high-dose Ara-C (HiDAC) based CNS-directed chemoimmunotherapy (CIT) alternating with anthracycline-based CIT. Our rationale for intensifying the CNS-directed therapy is the presence of intracerebral bleeding in two of our patients which would result in extravasation of lymphoma cells into the cerebral parenchyma with the development of CNS lymphoma. All three patients have achieved excellent therapeutic outcomes. Two patients with intracerebral bleeding have been in complete remission (CR) for about 11 years and 4 years. One patient was successfully induced into CR about 10 months ago and currently is in CR. This unique therapeutic approach should be further explored for CNS-IVL.

Clinical presentation, outcome, and prognostic markers in patients with intravascular large B-cell lymphoma, a lymphoma study association (LYSA) retrospective study

BACKGROUND

Intravascular large B-cell lymphoma (lVLBCL) is a very rare type of large B-cell lymphoma.

METHODS

We conducted a retrospective study on IVLBCL patients treated from 2000 to 2016 in LYSA cooperative group centers.

RESULTS

Sixty-five patients were identified in 23 centers. Median age at diagnosis was 69 years (range 23-92). Thirty-four patients (64%) had an IPI score >3 and 40 patients (67%) had a performance status ≥2. The most frequent extra-nodal locations were bone marrow (n = 34; 52%), central nervous system (n = 25; 39%), and skin (n = 21; 33%). Nodal involvement and endocrine system were observed in 34% (n = 22) and 18% (n = 12) of all cases, respectively. Twenty-six patients (41%) had macrophage activation syndrome. Tumor cells were frequently CD5 positive (52%) with a non-germinal center origin (86%). BCL2 was expressed in 87% of all samples analyzed (n = 20) and 43% of patients had a MYC/BCL2 double expression. Fifty-six patients were treated with a regimen of chemotherapy containing rituximab, among whom 73% reached complete remission. The median progression-free survival (PFS) and median overall survival (OS) were 29.4 months and 63.8 months, respectively. History of autoimmune disorder (Hazard ratio [HR] 3.3 [1.4-7.8]; p < 0.01), nodal involvement (HR 2.6 [1.4-5.1]; p < 0.01), lack of anthracycline (HR 0.1 [0-0.4] for use; p < 0.001), or no intensification at first-line regimen (p = 0.02) were associated with worse PFS. High-dose methotrexate use was not associated with better PFS or OS.

CONCLUSIONS

Our study highlights the aggressive clinical picture of IVLBCL, in particular the frequency of macrophage activation syndrome, and the need for new therapies despite a response to R-CHOP-like regimen similar to non-intravascular diffuse large B-cell lymphomas.

Intravascular large B-cell lymphoma with diffuse ground glass lesion on chest computed tomography diagnosed using transbronchial lung cryobiopsy: a case report

A 68-year-old man was presented with high fever of unknown origin for 3 weeks and non-productive cough for 1 week. A chest computed tomography (CT) scan revealed multiple nodules and ground glass opacities (GGO) in both lungs. The patient was initially diagnosed with hypersensitivity pneumonitis based on the result of bronchoalveolar lavage fluids (BALF). After treatment with methylprednisolone for 2 weeks, the patient’s fever recurred, with no resolution of lesions on chest CT. The patient consented to positron emission tomography (PET)/CT. It showed that fluorodeoxyglucose (FDG) metabolism was significantly increased in the spleen, whole skeleton, and both lungs, suggesting a malignant hematological disease. Large B-cell lymphoma was diagnosed by bone marrow puncture and flow cytometry. Transbronchial lung cryobiopsy was performed to evaluate the diffuse lung lesion. Hematoxylin-eosin (HE) staining showed diffuse infiltration of heterotypic cells in the pulmonary interstitial capillaries. Furthermore, immunohistochemical examination results suggested lung infiltration of B lymphohematopoietic system tumors. The patient was finally diagnosed as intravascular large B-cell lymphoma (IVLBCL). IVLBCL with diffuse lung ground glass lesions is very rare and difficult to diagnose. Transbronchial lung cryobiopsy, as an emerging procedure, plays an important role in the diagnosis of interstitial lung disease and has gained popularity for a lower complication rate and acquisition of more tissue samples.

CUTANEOUS B-CELL LYMPHOMAS: UPDATE ON DIAGNOSIS, RISK-STRATIFICATION, AND MANAGEMENT

PCBCLs are a group of Non-Hodgkin's B-cell lymphomas originating in and usually confined to the skin, representing approximately one fourth of primary cutaneous lymphomas (PCL). Their current classification system has been the result of the joint World Health Organization (WHO) - European Organization for Research and Treatment of Cancer (EORTC) consensus in 2018. To date, several types of PCBCLs have been described in the scientific literature, with different clinical presentation and prognosis. Primary cutaneous follicle-center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma (PCMZL) are the most common forms, with a typical indolent course. On the contrary, primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is less common, yet more aggressive, with a reported 5-year overall survival of approximatively 50%. In this review, we outline the PCBCLs defining diagnostic criteria, report the features of the less common subtypes and summarize the noteworthy therapeutical options currently available in this field.

Hemophagocytic syndrome and neurological involvement in a case of intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of non-Hodgkin's lymphoma, and is divided into Western and Asian variants. The latter is rarely found to have neurological system involvement. In China, there have only been a few diagnosed cases of IVLBCL. Here, we present a Chinese case of Asian-variant IVLBCL with neurological symptoms. A 32-year-old Chinese man presented with bilateral lower limb numbness and persistent fever. He also complained of difficulties in urination and defecation. In addition, splenomegaly and pancytopenia were observed. We identified 3% dysplastic lymphocytes in his peripheral blood film, and his bone marrow biopsy led to a diagnosis of Asian-variant IVLBCL. Lumbar spine magnetic resonance imaging, which revealed an edematous spinal cord, further confirmed neurological involvement. The patient refused treatment from the time of diagnosis, and died 2 months after being discharged. IVLBCL is a highly aggressive but nonspecific clinical manifestation that is difficult to diagnose; therefore, a greater understanding of the disease is needed. The current first-line therapy involves R-CHOP combination therapy (cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab); however, the overall prognosis of IVLBCL remains poor.

Intravascular large B-cell lymphoma affecting multiple cranial nerves: A histopathological study

Intravascular large B‐cell lymphoma (IVLBCL) is a rare form of lymphomas with poor prognosis, characterized by atypical lymphocytes selectively growing within the lumen of small or medium‐sized vessels. Here, we report a case of intracerebral IVLBCL in a 54‐year‐old man who died three months after symptom onset. The diagnosis was made by postmortem pathological examination, based on the identification of multiple ischemic lesions, with small or medium‐sized vessels filled with malignant B‐cells, in the cerebral hemispheres, cerebellum, midbrain, and medulla oblongata, including the external cuneate nucleus and trigeminal spinal tract nucleus. Apart from necrotic lesions, specific histopathological search for occluded vessels in the other brain stem structures permitted identification of significant involvement of the cuneate nucleus, solitary tract nucleus, hypoglossal nucleus, and inferior olivary complex. Small vessels affected by IVLBCL were also found in the trunks of the oculomotor, trigeminal, glossopharyngeal, vagal, and hypoglossal nerves. These histopathological findings were consistent with some cranial nerve symptoms/signs ascertained during hospitalization, such as diplopia, dysphonia, and asymmetry/hypomotility of the palatal veil. The case study presented here reports novel insights on radiological, anatomical, and clinical correlations of the IVLBCL, including the possible involvement of nuclei and trunks of multiple cranial nerves. The reported findings may help clinicians in the early identification of this rapidly progressive disease that can be easily misdiagnosed, through integrated neuroradiological, neurological and neuropathological approaches.

Current progress and future perspectives of research on intravascular large B-cell lymphoma

Intravascular large B‐cell lymphoma is a rare disease of the large B cells characterized by selective growth in the lumina of small vessels in systemic organs. Since first reported in 1959, the difficulty of obtaining sufficient tumor cells from biopsy specimens has hampered the elucidation of its underlying biology. Recent progress using xenograft models and plasma cell‐free DNA has uncovered genetic features that are similar to those of activated B‐cell type diffuse large B‐cell lymphoma, including MYD88 and CD79B mutations and frequent alterations in immune check point‐related genes such as PD‐L1 and PD‐L2. Given the improvement in clinical outcomes and a higher risk of secondary central nervous system (CNS) involvement in the rituximab era, a phase 2 trial of R‐CHOP combined with high‐dose methotrexate and intrathecal chemotherapy as a CNS‐oriented therapy has been conducted. This trial, the PRIMEUR‐IVL study, has displayed good progression‐free survival and a low cumulative incidence of secondary CNS involvement. Long‐term follow‐up within this trial is still ongoing. Further understanding of the pathophysiology of the disease and improvements in clinical outcomes are still needed.

Diffuse large B-cell lymphoma (DLBCL) with significant intravascular invasion. Close resemblance of its clinicopathological features to intravascular large B-cell lymphoma, but not to DLBCL-not otherwise specified

Intravascular large B-cell lymphoma (IVLBCL) is defined by the World Health Organization (WHO) Classification as one type of extranodal large B-cell lymphoma and it is characterized by the selective growth of lymphoma cells within blood vessels with minimal extravascular invasion. According to the criteria, however, several reported cases of IVLBCL with significant extravascular invasion cannot be classified as IVLBCL. The purpose of the present study was to assess the clinicopathological significance of the WHO criteria for IVLBCL. We characterized clinical, histopathological, and immunohistochemical features of 11 patients with extranodal diffuse large B-cell lymphoma (DLBCL) with significant intravascular invasion (DLBCL-IV), and statistically compared their features with those of 11 patients with IVLBCL and 15 patients with extranodal DLBCL with virtually no intravascular invasion (DLBCL-noIV). When compared with the DLBCL-noIV group, the DLBCL-IV group was characterized by significantly higher rates of splenomegaly, hemophagocytosis, advanced stage disease, and CD5 expression; higher average platelet count, serum lactate dehydrogenase level, and serum ferritin level. Progression-free survival was significantly shorter in the DLBCL-IV group than the DLBCL-noIV group. In contrast, there were no significant differences in clinicopathological features between the DLBCL-IV and the IVLBCL groups. Our study suggests that DLBCL-IV should be regarded as IVLBCL-related.

ICAM1-Negative Intravascular Large B-Cell Lymphoma of the Pituitary Gland: A Case Report and Literature Review

Objective

Intravascular large B-cell lymphoma (IVLBCL) is a rare and aggressive type of B-cell lymphoma with large cells growing within the lumen of blood vessels. Although previous reports revealed highly variable symptoms resulting from small-vessel occlusion by neoplastic cells in a variety of organs, there are few reports of IVLBCL with pituitary involvement.

Method

We present a case of IVLBCL with pituitary infiltration from our institution together with a literature review of similar cases to better understand this rare case of IVLBCL involving the pituitary gland.

Results

Our case and the pertinent literature demonstrated that IVLBCL with pituitary involvement predominantly occurred in women at a mean age of 64 years, and most of them showed panhypopituitarism that was reversible after standard therapy of rituximab-containing chemotherapy with intrathecal methotrexate. Notably, the pituitary biopsy in our case revealed that atypical large B-cells found within blood vessels and the pituitary gland were negative for intercellular adhesion molecule 1. Intercellular adhesion molecule 1-negative lymphoid cells may have contributed to panhypopituitarism by extravasation into the pituitary tissues, which do not have a blood-brain barrier and receive abundant blood flow.

Conclusion

IVLBCL of the pituitary gland is a rare lymphoma with nonspecific manifestations and a dismal prognosis. Recognition of the clinicopathological features is necessary for early clinical diagnosis and appropriate treatment.

Intravascular Large B-Cell Lymphoma and Renal Clear Cell Carcinoma as Collision Tumor: A Case Report and Review of the Literature

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of extranodal large B-cell lymphoma characterized by the selective growth of lymphoma cells within the lumina of vessels. The patient usually presents with nonspecific symptoms and a remarkable deterioration in performance status. The occurrence of synchronous IVLBCL and renal cell carcinoma (RCC) is extremely rare. A right kidney tumor was found in a 72-year-old man with a history of low back pain. The kidney was enlarged, with a tumor mass measuring 4.5 × 4 × 4 cm. Sections exhibited a RCC (clear cell type, nuclear grade I). Also an extensive tumor affecting capillaries and small veins was present, positive for CD45, CD20, BCL-2, and MUM1/IRF-4, consistent with IVLBCL. The lymphoma was circumscribed to the RCC. The final diagnosis was IVLBCL with a RCC as collision tumor. After that, with neurological findings, central nervous system compromise by lymphoma was made. The patient started a first cycle of chemotherapy, progressive deterioration of the sensorium, and positive blood cultures for Klebsiella pneumoniae and Escherichia coli. The patient died 8 days later of acute respiratory failure. No autopsy was done. IVLBCL is an aggressive and systemic disease characterized by massive proliferation of tumor cells without a known primary site. Clinical identification and histopathologic diagnosis are relevant issues in the therapeutic management of these lymphomas. Until now, only one case of IVLBCL coexisting with RCC has been reported. In this article, we report a second case of IVLBCL with RCC simultaneous, as an unusual collision tumor.

Primary Central Nervous System Lymphomas: A Diagnostic Overview of Key Histomorphologic, Immunophenotypic, and Genetic Features

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin lymphoma that primarily arises in the brain, spinal cord, leptomeninges, and vitreoretinal compartment of the eye. The term is sometimes used interchangeably with primary central nervous system diffuse large B-cell lymphoma (PCNS DLBCL) because DLBCL comprises a great majority (90–95%) of PCNSL. Although rare, other types of lymphomas can be seen in the central nervous system (CNS), and familiarity with these entities will help their recognition and further workup in order to establish the diagnosis. The latter is especially important in the case of PCNSL where procurement of diagnostic specimen is often challenging and yields scant tissue. In this review, we will discuss the most common types of primary lymphomas that can be seen in the CNS with emphasis on the diagnostic histomorphologic, immunophenotypic, and molecular genetic features. The differential diagnostic approach to these cases and potential pitfalls will also be discussed.

The adhesion molecule ICAM-1 in diffuse large B-cell lymphoma post-rituximab era: relationship with prognostic importance and rituximab resistance

Intercellular adhesion molecule-1 (ICAM-1) is a cell-surface receptor contributing to lymphocyte homing, adhesion and activation. The prognostic significance of the protein is unknown in diffuse large B-cell lymphoma (DLBCL) in post-rituximab era. We detected expression of ICAM-1 immunohistochemically in 102 DLBCL tissue samples. Overexpression of ICAM-1 was found in 28 (27.5%) cases. In patients with low ICAM-1 expression levels, the addition of rituximab to CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy resulted in an improved overall response rate, progression-free survival (PFS) and overall survival (OS) (P=0.019, 0.01, 0.02). In pre-clinical models, we found that chronic exposure of cell lines to rituximab led to downregulation of ICAM-1 and acquirement of a rituximab resistant phenotype. In vitro exposure of rituximab resulted in rapid aggregation of B-cells regardless of the ICAM-1 expression levels. MTT assay showed knockdown of ICAM-1 could cause rituximab resistance. Neutralization of ICAM-1 did not affect rituximab activity in vitro and in vivo. Our data illustrated that in post-rituximab era, R-CHOP significantly improved the ORR, PFS and OS in ICAM-1 negative subset patients. Downregulation of ICAM-1 may contribute to rituximab resistance, and that rituximab, by promoting cell-cell aggregation, may sensitize cells to the cytotoxic effects of chemotherapy agents.

Intravascular Large B-cell Lymphoma: A Report of Two Cases

One of the rare variants of extranodal large B-cell lymphoma is intravascular large B-cell lymphoma (IVLBCL). Characteristics of IVLBCL include intraluminal selective proliferation of atypical lymphoid cells in small to medium-sized vessels. The etiologic of IVLBCL is unknown, but due to the growth pattern of this tumor, it is speculated that IVLBCL is caused by a defect in homing receptor of tumor cells. IVLBCL can involve any organ but central nervous system, lungs, and skin are the most involved sites. IVLBCL does not usually involve lymph nodes. IVLBCL mainly occurs in the middle aged to elderly population with a slight male predominance. Generally, IVLBCL is aggressive and rapidly fatal if left untreated.

We here reported two cases of IVLBCL who succumbed to the disease at initial phase of treatment to emphasize the difficulty in diagnosis of IVLBCL due to its exclusive intravascular growth pattern and fulminant clinical course.

Bone marrow infiltration pattern in patients with intravascular large B-cell lymphoma diagnosed by random skin biopsy

We retrospectively analyzed bone marrow (BM) infiltration pattern in consecutive 30 intravascular large B-cell lymphoma (IVLBCL) patients diagnosed by random skin biopsy (RSB). BM infiltration of lymphoma was observed in 18 patients (60.0%), including five patients with the intrasinusoidal pattern with minimal extravasation, eight patients with the mixed of intrasinusoidal and scattered/interstitial or nodular infiltration, and five patients with the nodular/diffuse pattern. Twelve patients were negative for lymphoma infiltration. BM histology of patients with IVLBCL were diverse and frequently discordant with those of other site of IVLBCL lesions. BM biopsy had a poorer diagnostic performance for detecting intravascular features.

Ischemic Optic Neuropathy Secondary to Intravascular Lymphoma

BACKGROUND

To describe a case of optic neuropathy associated with intravascular lymphoma (IVL).

METHODS

Case report and review of the literature.

RESULTS

A case of asymmetric binocular vision loss is described, preceded by transient vision loss. Associated optic perineural enhancement and enhancing and diffusion-positive cortical lesions were observed on magnetic resonance imaging. Biopsy of the cerebellum revealed exclusively intraluminal neoplastic B-cells consistent with IVL.

CONCLUSIONS

Patients with IVL may rarely present with optic nerve involvement, presumably due to small vessel occlusion. The presentation may mimic features of anterior ischemic optic neuropathy including an acute onset and disc edema. Although optic nerve enhancement and associated white matter lesions may suggest optic neuritis, enhancement of the optic nerve sheath, as in this case, has a wide differential diagnosis, which includes giant cell arteritis. IVL should be considered in atypical cases of optic neuropathy accompanied by enhancing, diffusion-positive brain lesions that are not within a specific vascular territory.

Transcriptome complexity in intravascular NK/T-cell lymphoma

AIMS

Intravascular NK/T-cell lymphoma (IVNKTCL) is a rare disease, which is characterised by exclusive growth of large cells within the lumen of small vessels, Epstein-Barr virus infection and somatic mutations in epigenetic regulator genes. Here, we elucidate the transcriptomic complexity of IVNKTCL.

METHODS

IVNKTCL cases were retrieved from a single-centre cohort of 25 intravascular lymphomas. RNA-seq and whole exome sequencing (WES) were performed to analyse transcriptomic abnormalities and mutations in splicing factors.

RESULTS

Approximately 88% of the total reads from the RNA-seq were considered exonic, while the remaining reads (12%) were mapped to intronic or intergenic regions. We detected 28,941 alternative splicing events, some of which would produce abnormal proteins rarely found in normal cells. The detected events also included tumour-specific splicing alterations in oncogenes and tumour suppressors (e.g., HRAS, MDM2 and VEGFA). WES identified premature termination mutations or copy number losses in a total of 15 splicing regulator genes, including SF3B5, SRSF12 and TNPO3.

CONCLUSIONS

This study raises the possibility that IVNKTCL may be driven by multiple complex regulatory loops, including non-exonic expression and aberrant splicing, in addition to defects in epigenetic regulation.

Intravascular Lymphoma with Progressive CNS Hemorrhage and Multiple Dissections

Introduction

Intravascular lymphoma (IVL) is an uncommon and often fatal disease characterized by intraluminal proliferation of lymphomatous cells within blood vessels. Because of a heterogeneous clinical presentation and lack of sensitive diagnostic protocols, diagnosis of IVL is most often made at autopsy. However, with early diagnosis and appropriate chemotherapy, the prognosis is greatly improved and complete remission is possible. In order to broaden the possible presentations of IVL, we present a patient with an atypical manifestation of biopsy-proven intravascular large B-cell lymphoma who suffered dissections of both intracranial and extracranial arteries in addition to progressive intracranial hemorrhages. Case Report. A 47-year-old woman presented with unilateral paresthesias. She developed progressive multifocal infarcts and hemorrhage with dissections of both intracranial and extracranial arteries, resulting in coma. Brain biopsy revealed IVL. She received aggressive chemotherapy and remains in complete remission with good neurologic recovery.

Conclusion

IVL is known to exert its pathology on small arteries and capillaries, but is not known to cause dissections of large vessels. The diagnosis should be considered in cases with unexplained arterial dissections and progressive strokes. Early diagnosis with appropriate laboratory screening and tissue confirmation by biopsy can lead to greatly improved outcomes.

Pulmonary intravascular large B-cell lymphoma accompanying synchronous primary pulmonary adenocarcinoma and benign interstitial lesions

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of extranodal large B-cell lymphoma, and initial or predominant presentation in the lungs is uncommon. The synchronous occurrence of IVLBCL and malignant tumors is less frequent, and no such reports have described pulmonary presentations. We report a rare case of pulmonary IVLBCL accompanying lung cancer and interstitial lesions. A 73-year-old man with a history of pneumonia underwent a follow-up examination. Computed tomography revealed diffuse, bilateral ground-glass opacities (GGO) with a partial solid mass. Histologically, the mass consisted of adenocarcinoma. However, two other types of interstitial lesions were scattered throughout the resected lung: 1) peribronchovascular thickening with the aggregation of macrophages and anthracosis, and 2) alveolar septal thickening in the centrilobular area with atypical CD20-positive large cells in the capillaries. These two types of lesions were not mixed. Computed tomography and positron emission tomography demonstrated no other organ involvement. The patient was considered to have the synchronous occurrence of pulmonary IVLBCL and lung cancer (adenocarcinoma). After R-CHOP therapy, GGO on CT disappeared. Lung cancer often accompanies benign background lesions, and the combination of these lesions with lung cancer may make it difficult to detect the presence of pulmonary IVLBCL. However, the histological distribution pattern of IVLBCL may be a clue to the correct diagnosis.

Unusual and Fatal Case of an Undiagnosed Intravascular Large B-cell Lymphoma: The Oncologist's Great Imitator†

Intravascular lymphoma (IVL) is a rare subtype of extranodal lymphomas that is characterized by the selective growth of neoplastic cells within the lumen of small vessels. Authors document the case of an unexpected death caused by an undiagnosed intravascular large B-cell lymphoma with multi-organ involvement, which had initially manifested as an infection and then as an unclarified central nervous system pathology. Histological examination showed a diffuse intravascular large B-cell brain lymphoma with prominent cerebral involvement. The relevance of the case report reveals the importance of an autopsy of an extremely rare and threatening pathology that in most cases is diagnosed only postmortem. As a result, the role of the forensic pathologist becomes particularly important. When specifically performing an in-depth autopsy evaluation with a specific histologic analysis, it is possible to identify the intravascular lymphoma and declare a more accurate cause of death.

Intravascular Lymphoma Presenting as a Cavernous Sinus Tumor

Intravascular lymphoma (IVL) is a malignant lymphoma that lacks the expression of cell surface adhesion molecules so that cells fluidly migrate within the blood vessels. The patient in the present study had restricted eye movement caused by IVL, mimicking a cavernous sinus tumor. Because the cavernous sinus lumen is divided into multiple compartments by trabeculae and venous channels, IVL tumor cells were trapped in these compartments, thus forming a mass, which subsequently extended into the contralateral cavernous sinus via the anterior and posterior intercavernous sinuses. This is a rare case of IVL forming a mass inside the cavernous sinus.

Nephrotic syndrome without kidney injury revealing intravascular large B cell lymphoma

We describe the case of a 64-year-old woman admitted for fever of unknown origin, who developed nephrotic syndrome during hospitalisation and pulmonary infiltrates. Renal biopsy disclosed intracapillary glomerular invasion by intravascular large B cell lymphoma. Clinical and biological evolution was favourable after rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone (R-CHOP) treatment and autologous stem cell transplant. Two years after diagnosis the patient was considered in remission.

Intravascular NK/T-cell lymphoma: clinicopathological and integrated molecular analysis of two cases provides a clue to disease pathogenesis

Aims

To elucidate the clinicopathological and molecular features of intravascular NK/T-cell lymphoma (IVNKTCL).

Methods

Two cases of IVNKTCL were retrieved from a single-centre cohort composed of 25 intravascular lymphomas. Whole-exome and RNA sequencing and immunohistochemistry were performed.

Results

We identified somatic mutations in the following epigenetic regulators: four histone genes (HIST1H2AN, HIST1H2BE, HIST1H2BN and H3F3A), histone deacetylase (HDAC5), two helicases (WRN and DDX3X), two methylation-related enzymes (TET2 and DNMT1) and the SNI/SWF pathway (ARID1A). Copy number analysis identified driver gene alterations comprising the loss of ARID1B, HACE1 and SMAD4, and the gain of SOX2 and histone clusters. RNA sequencing analysis did not indicate the presence of any fusion gene. Both cases were positive for Epstein-Barr virus (EBV) and showed strong expression of programmed death-ligand 1 (PD-L1).

Conclusions

This study raises the possibility that, at least for some patients, IVNKTCL may be considered an epigenetic disease with EBV infection-associated aetiopathogenesis.

Intravascular B-large cell lymphoma: an unexpected diagnosis of an incidental adrenal mass

Adrenal incidentalomas originally defined as tumors discovered serendipitously in the course of diagnostic evaluation or follow-up of unrelated disorders, may occasionally pose serious diagnostic challenges. Intravascular large B-cell lymphoma (IVLBCL) may be a rare example of such a case. We present an IVLBCL confined to the adrenal gland in a 52-year-old man focusing on its diagnostic and therapeutic aspects. On endocrine work up, the tumor was hormonally inactive and exhibited inconclusive imaging characteristics without signs of locoregional spread. After a left laparoscopic adrenalectomy, histologic sections revealed the presence of tumor cells inside dilated, thin-walled vascular spaces. Immunohistochemical stains confirmed the diagnosis of IVLBCL. The patient was then referred to a Hematology Unit for further staging and treatment and received six cycles of R-CHOP. Despite the fact that IVLBCL carries a dismal prognosis our patient remains alive and in complete remission 6 years after the initial diagnosis.

Intravascular large B-cell lymphoma presenting with diffusely increased pulmonary fluorodeoxyglucose uptake without corresponding CT abnormality

A 60-year-old male presented with complaints of dyspnea, intermittent fever, and 40 pounds of weight loss over the previous 9 months and was admitted for acute hypoxemic respiratory failure. Labs demonstrated elevated inflammatory markers, mild anemia, and thrombocytopenia. Fluorodeoxyglucose-positron emission tomography scan demonstrated diffusely increased pulmonary fluorodeoxyglucose uptake without corresponding abnormality on CT images. Excisional lung biopsy demonstrated intravascular large B-cell lymphoma (IV-LBCL). Presentation, imaging findings, and diagnosis of IV-LBCL will be discussed, as well as differential considerations for pulmonary involvement by IV-LBCL.

Canine Cerebral Intravascular Lymphoma: Neuropathological and Immunohistochemical Findings

Intravascular lymphoma (IVL) is a rare angiotropic large-cell lymphoma in which neoplastic lymphocytes proliferate within the lumina of small blood vessels in the absence of a primary extravascular mass or leukemia. This study included 10 cases of canine IVL restricted to the CNS. Dogs had an average age of 8 years and neurological signs mainly referred to brain involvement such as depression, seizures, and ambulatory deficits. Gross examination at necropsy showed focal extensive or multiple hemorrhagic areas mainly distributed in the telencephalon and diencephalon. Histopathologically, numerous veins and capillaries were filled with neoplastic lymphoid cells, accompanied by edema, hemorrhage, and thrombosis. Immunohistochemistry (IHC) for CD3, CD20, and PAX5 was performed to phenotype the neoplastic lymphocytes. IHC for CD44 and CD29 were used to investigate the pathogenetic mechanism leading to the intravascular aggregation of the neoplastic lymphocytes. The same IHC panel was applied to 8 cases of primary and metastatic canine CNS lymphoma in order to compare IVL immunoreactivity. Three IVLs were typified as T-cell, 3 as B-cell, and 4 as non-T non-B. Neoplastic lymphocytes showed marked expression of CD44 in all IVL cases, and CD29-immunolabeled cells were observed in 4 IVLs. CD44 immunoreactivity was consistent with the findings reported in human IVL, suggesting a predisposition to the formation of lymphocyte aggregates. CD29 was inconsistently immunonegative in canine IVL, confirming only partially the pathogenetic mechanism suggested for the human counterpart.

Recurrent cerebrovascular accidents caused by intravascular lymphoma in a dog

An eight-year-old, neutered male labrador was presented with recent recurrent vestibular episodes. MRI was consistent with multiple lacunar ischaemic infarcts in the thalamus and medulla oblongata. The imaging diagnosis was supported by a markedly elevated D-dimer concentration. Despite a comprehensive diagnostic workup (including fine needle cytology of cutaneous and subcutaneous nodules, complete bloodwork, urinalysis, thoracic and abdominal imaging, cerebrospinal fluid analysis, serial blood pressure measurements, echocardiography, electrocardiography and brainstem auditory evoked response testing), no underlying cause was found. After a partial response to 2  mg/kg clopidogrel once a day and 1  mg/kg prednisolone once a day, the dog acutely deteriorated and repeated MRI of the brain revealed an intra-axial haemorrhagic mass. Euthanasia was elected and postmortem examination revealed the presence of an intravascular null-cell lymphoma, exclusively in the central nervous system. Intravascular lymphoma is rare, difficult to diagnose ante-mortem and reports in veterinary literature are few.