The [18F]FDG PET/CT is a crucial tool in the diagnostic process and monitoring of neoplastic diseases. Currently, during the global program of vaccination against COVID-19 and the possibility of axillary lymphadenopathy after this injection, the correct interpretation of PET/CT images is vitally significant and may create some difficulties. We present a case of increased uptake of [18F]FDG in an axillary lymph node in a PET/CT scan performed 2 days after the Pfizer BioNTech COVID-19 vaccine in a 48-year-old patient newly diagnosed with marginal zone B-cell lymphoma.

This case report delineates the intricate interplay between psychiatric and oncological pathology in a 72-year-old male diagnosed with low-grade marginal zone B-cell lymphoma and severe psychiatric disturbances, including catatonia. The presentation of severe psychiatric symptoms initially obscured the underlying lymphoma, delaying diagnosis and complicating clinical management. Notably, the lymphoma itself may have precipitated or exacerbated the psychiatric condition, underscoring the potential for oncological diseases to manifest with rapidly progressive dementia and catatonia. A multidisciplinary approach was employed, utilizing electroconvulsive therapy (ECT) for rapid resolution of catatonia, which facilitated significant mental health improvements and clearer delineation of the oncological underpinnings. Concurrently, the patient was treated with rituximab, targeting the lymphoma. This case highlights the critical need for a comprehensive evaluation in patients presenting with psychiatric symptoms, particularly in the elderly, to uncover potential medical causes and illustrates the efficacy of ECT in managing psychiatric conditions that may overshadow or complicate concurrent medical issues.

Primary cutaneous marginal zone lymphoma (PCMZL) is a rare form of B-cell lymphoma that primarily affects the skin. Chronic antigen stimulation has been implicated in its development, with cases associated with various triggers. We present a case of PCMZL following chronic inflammation caused by long-term hair dyeing. A 75-year-old woman with a history of repeated inflammation and itching after hair dyeing for 30 years presented with persistent red-to-violaceous patches and plaques on her scalp. Despite receiving topical corticosteroid treatment for 10 years, the lesions remained. Pathological examinations confirmed the diagnosis of PCMZL. The patient achieved complete remission after radiotherapy. This case underscores the potential link between chronic inflammation and the development of PCMZL.

B-cell lymphomas are neoplastic diseases occasionally associated with chronic inflammation. mRNA vaccines for coronavirus disease 2019 (COVID-19) induce inflammatory responses, which often lead to fever and lymphadenopathies indistinguishable from lymphomas. Although both lymphadenopathies and lymphomas can be influential, the correlation between them is unclear. Herein, we present the first case of marginal zone B-cell lymphoma following mRNA COVID-19 vaccination. An 80-year-old Japanese woman presented with a right temporal mass that appeared the morning after she was administered her first mRNA COVID-19 vaccination (BNT162b2). The mass gradually decreased in size but persisted over 6 weeks after her first vaccination (3 weeks after her second vaccination). At her first visit to our hospital, ultrasound revealed the size of the mass to be 28.5 × 5.7 mm, and computed tomography revealed multiple lymphadenopathies in the right parotid, submandibular, jugular, and supraclavicular regions. Initially, we suspected head-and-neck benign lymphadenopathy as a side effect of vaccination. Nine weeks later, the number of swollen submandibular and parotid glands increased, and the lymph nodes further enlarged. Finally, the right temporal mass was diagnosed as marginal zone B-cell lymphoma based on immunohistochemical and flow cytometry findings of biopsy specimens. Our findings suggest that although 4-6 weeks of observation for lymph node inflammation after the second vaccination is recommended, malignancy should also be considered in the differential diagnosis of lymphadenopathy following vaccination.

UNASSIGNED: Primary central nervous system lymphoma (PCNSL) is an aggressive extranodal subtype of nonHodgkin\'s lymphoma. Ventricle-predominant PCNSL, arising in the CNS ventricular system, is a rare entity. In over 90% of cases, PCNSL is classified as diffuse large B-cell lymphoma. Rarely, PCNSL may be classified as marginal zone B-cell lymphoma (MZBCL) of mucosa-associated lymphoid tissue (MALT). Taken together, a primary MALT-type MZBCL arising in a cerebral ventricle is an extremely rare presentation.
UNASSIGNED: A 69-year-old female presented with a persistent left frontal headache for 1 year. Magnetic resonance imaging revealed an enhancing soft-tissue lesion within the left lateral ventricle, with associated periventricular edema. We performed an excisional biopsy of the tumor, which grossly had the appearance of a meningioma. Histopathology of the tumor was consistent with MZBCL of the MALT type. The patient was treated with Rituximab and Ibrutinib. Six months after surgery, she remained neurologically intact and free of disease.
UNASSIGNED: We report the case of a primary MALT-type MZBCL arising in the CNS ventricular system, with characteristics mimicking meningioma. This lymphoma involved the lateral ventricle and likely originated from the choroid plexus. Meningothelial cells and epithelial cells in the choroid plexus may acquire MALT in response to chronic inflammatory stimuli, such as infection or autoimmune disease. In rare cases, MALT lymphoma may develop as part of this pathogenesis.

Carriers of the mutated CDH1 gene have an increased risk of developing early-onset signet-ring cell (diffuse) gastric cancer. We present a case of a young patient with a confirmed mutation of the CDH1 gene, who was diagnosed with a gastric marginal zone B-cell lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT lymphoma) from surveillance endoscopy. He underwent Helicobacter pylori eradication treatment and was subsequently submitted to a total prophylactic gastrectomy. The surgical specimen only revealed foci of signet-ring cell carcinoma (SRCC) in situ without lymphoma signs. We highlight here the occurrence of other pathology in high-risk patients as well as its possible influence on the decision to perform gastrectomy.
A mutação do gene CDH1 determina um risco aumentado de desenvolvimento precoce de cancro gástrico de células em anel de sinete (tipo difuso). Apresentamos um caso de um doente jovem portador de uma mutação no gene CDH1 que foi diagnosticado com linfoma de MALT gástrico numa endoscopia de vigilância. O doente foi submetido a terapêutica de erradicação da Helicobacter pylori e subsequentemente realizou uma gastrectomia total profilática. A avaliação histológica da peça cirúrgica identificou focos de carcinoma in situ de células de anel em sinete, sem evidência de linfoma. O nosso objetivo é salientar a ocorrência de outras patologias em doentes de alto risco assim como a sua possível influência na decisão cirúrgica.

Lymphoma is the most common primary tumor of the orbit, accounting for 55% of all orbital malignancies. When divided into histopathological subtypes, extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) comprises the largest proportion. Clinical manifestations are unspecific, but in patients with slow-growing painless orbital mass, or red conjunctival lesion suggestive of \'salmon patch\', ocular adnexa lymphoma (OAL) should be suspected. Although the pathogenetic mechanism of ocular adnexal MALT lymphoma (OAML) is not yet fully understood, the relationship between OAML and Chlamydia psittaci has been hypothesized recently, similar to that between gastric MALT lymphoma and Helicobacter pylori. This suggests a new treatment option for OAML; bacterial eradication therapy with systemic antibiotics. Several other treatment methods for OAML have been introduced, but no treatment guidelines have been established yet. In this article, we summarize the current knowledge on the clinical features, pathogenesis, diagnostic methods, therapeutic strategies, and prognosis of OAML.

Marginal zone B-cell lymphomas (MZBCLs) are non-Hodgkin lymphomas arising from postgerminal center marginal zone B cells. MZBCLs are subclassified into extranodal, nodal, and splenic MZBCLs. Primary nondural central nervous system (CNS) MZBCLs of the mucosa-associated lymphoid tissue (MALT) type are among the extranodal examples. Their clinicopathological features are not well characterized. Therefore, the clinicopathological features of 8 primary nondural CNS MZBCLs of the MALT type were assessed to establish their pathological diagnostic criteria. Histologically, all cases of primary nondural CNS MZBCLs of the MALT type showed perivascular expansive monotonous proliferation of small atypical B lymphoid cells with plasma cell differentiation, low Ki-67 labeling index, and minimal invasion from the perivascular space. In addition, no vascular changes such as glomeruloid changes, obliterative fibrointimal proliferation, and intramural lymphocytic infiltration were seen. These key histological characteristics should be considered when diagnosing cases that are suspected to be primary nondural CNS MZBCLs of the MALT type. Additionally, regarding PCR for the detection of immunoglobulin heavy variable gene and T-cell receptor γ gene rearrangements, the former is detected, but the latter is not detected in all cases. Therefore, PCR detection including sequence analysis should be added when diagnosing difficult cases based on the key histological characteristics.

Primary MALT lymphoma arising at the dura is a rare circumstance with no categorical therapeutic plan in literature. There are few reports available with different treatment courses. Here, we report two cases with a long-term follow-up after the same pattern of management and review the literature.

Owing to its heterogeneity and rarity, management of disseminated marginal zone B-cell lymphoma (MZL) remains largely understudied. We present prospective data on choice of systemic treatment and survival of patients with MZL treated in German routine practice. Of 175 patients with MZL who had been documented in the prospective clinical cohort study Tumour Registry Lymphatic Neoplasms (NCT00889798) collecting data on systemic treatment, 58 were classified as extranodal MZL of mucosa-associated lymphoid tissue (MALT) and 117 as non-MALT MZL. We analyzed the most commonly used first-line and second-line chemo(immuno)therapies between 2009 and 2016 and examined objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and prognostic factors for survival. Compared to patients with MALT MZL, those with non-MALT MZL more often presented with bone marrow involvement (43% vs. 14%), Ann Arbor stage III/IV (72% vs. 57%) and were slightly less often in good general condition (ECOG = 0; 41% vs. 47%). In German routine practice, rituximab-bendamustine for a median of 6 cycles was the most frequently used first-line (76%) and second-line treatment (36%), with no major differences between MZL subtypes. The ORR for patients encompassing any positive response was 81%. For patients with MALT and non-MALT MZL, respectively, 5-years PFS was 69% (95% CI 52%-81%) and 66% (95% CI 56%-75%), 5-years OS 79% (95% CI 65%-89%) and 75% (95% CI 66%-83%). Cox proportional hazards models showed a significantly increased risk of mortality for higher age in all patient groups. Our prospective real world data give valuable insights into the management and outcome of non-selected patients with MZL requiring systemic treatment and can help optimize therapy recommendations.