Regression of mucosa-associated lymphoid tissue lymphoma of the bladder after antibiotic therapy

Rare primary bladder mucosa-associated lymphoid tissue lymphoma: A case report and review of literature

Primary bladder mucosa-associated lymphoid tissue (MALT) lymphoma is an extremely rare bladder tumor. Only scarce reports have been reported. We hereby report a case of an 81-year-old female patient with bladder tumor presenting with frequent urination and dysuria, whose pelvic magnetic resonance imaging (MRI) considered bladder cancer. She underwent transurethral resection of the bladder tumor (TURBT), and histopathology confirmed the mass to be bladder MALT lymphoma. The patient refused further treatment, and no disease recurrence one year after surgery. The current data are insufficient to draw conclusions about the long-term efficacy of treatment for this tumor, regular follow-up is necessary. To further understand the clinical features, pathology, treatment and prognosis of this tumor, we have searched the literature from 1990 to the present, analyzing a total of 64 cases of primary MALT lymphoma.

MALT Lymphoma of the Urinary Bladder Shows a Dramatic Female Predominance, Uneven Geographic Distribution, and Possible Infectious Etiology

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) of the urinary bladder is an extremely rare entity accounting for 0.2% of all malignant urinary bladder neoplasms, and the diagnosis could be challenging. We present here a patient with urinary bladder MALT lymphoma and review of all published case reports in the literature. We summarized the reported immunophenotype of the neoplasm, ancillary studies, therapy, and follow-up for all 59 patients in the table. The median patients’ age was 57 years-old (range, 17 to 88), with female predominance in 50 of 59 patients representing a 1:5.6 ratio. Geographical distribution of the reported patients was as follows: 22 from Asia, of which more than a half (16) originated from Japan; 28 from Europe, of which 19 reported from the United Kingdom, and 3 patients were reported from the United States (including our patient). Twenty-three (77%) of 30 patients, for whom their clinical presentation was recorded, had symptoms of cystitis; Escherichia coli was the most common pathogen. We concluded that a prominent female predominance, uneven geographic distribution of urinary bladder MALT lymphoma, and a success of antibacterial therapy in selected cases suggest the link between urinary tract infection and urinary bladder MALT lymphoma.

Primary bladder mucosa-associated lymphoid tissue lymphoma: A case report and literature review

INTRODUCTION

Primary bladder mucosa-associated lymphoid tissue (MALT) lymphoma is a rare tumor. To date, the PubMed database contains only 39 English articles covering 63 cases of primary bladder MALT lymphoma. Herein, we report a case of this disease and review the current literature.

PATIENT CONCERNS

A 77-year-old woman presented with frequent urination, urinary urgency, and dysuria for 3 years. In the past 3 years, the patient's symptoms recurred and progressively worsened, and she was admitted to the hospital.

DIAGNOSIS

A histopathological examination revealed the bladder mass as a tumor with high proliferation of atypical B-lymphocytes. Immunohistochemistry showed positive results for CD20, PAX-5, Ki-67, BCL-2, and CD21 and negative results for CD10, MUM1, TDT, and cyclin D1. These data supported the diagnosis of primary bladder MALT lymphoma.

INTERVENTIONS

A transurethral resection of bladder tumor was performed to treat the disease.

OUTCOMES

The patient was alive and healthy at the 15-month follow-up.

CONCLUSION

Primary bladder MALT lymphoma is a rare disease and can be easily missed or misdiagnosed before achieving a histological confirmation. Surgery may be the best choice for both diagnosis and treatment.

Quinone and nitrofurantoin redox cycling by recombinant cytochrome b5 reductase

NADH cytochrome b₅ reductase mediates electron transfer from NADH to cytochrome b₅ utilizing flavin adenine dinucleotide as a redox cofactor. Reduced cytochrome b₅ is an important cofactor in many metabolic reactions including cytochrome P450-mediated xenobiotic metabolism, steroid biosynthesis and fatty acid metabolism, hemoglobin reduction, and methionine and plasmalogen synthesis. Using recombinant human enzyme, we discovered that cytochrome b5 reductase mediates redox cycling of a variety of quinones generating superoxide anion, hydrogen peroxide, and, in the presence of transition metals, hydroxyl radicals. Redox cycling activity was oxygen-dependent and preferentially utilized NADH as a co-substrate; NADH was 5-10 times more active than NADPH in supporting redox cycling. Redox cycling activity was greatest for 9,10-phenanthrenequinone and 1,2-naphthoquinone, followed by 1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone (menadione), nitrofurantoin and 2-hydroxyestradiol. Using menadione as the substrate, quinone redox cycling was found to inhibit reduction of cytochrome b₅ by cytochrome b₅ reductase, as measured by heme spectral changes in cytochrome b₅. Under anaerobic conditions where redox cycling is inhibited, menadione had no effect on the reduction of cytochrome b₅. Chemical redox cycling by cytochrome b₅ reductase may be important in generating cytotoxic reactive oxygen species in target tissues. This activity, together with the inhibition of cytochrome b₅ reduction by redox-active chemicals and consequent deficiencies in available cellular cytochrome b₅, are likely to contribute to tissue injury following exposure to quinones and related redox active chemicals.

Antibiotic therapy in nongastrointestinal MALT lymphoma: a review of the literature

Although antibiotic therapy has been established as the standard of care in patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, much less is known about the value of antibiotic therapy in nongastrointestinal (non-GI) MALT lymphomas. A computerized search (Medline) accompanied by a manual search to identify clinical reports on the topic of antibacterial therapy in patients with non-GI MALT lymphomas was performed. The majority of data were available for MALT lymphoma of the ocular adnexa (OAML) including a total of 131 patients in 4 retrospective studies, 3 prospective series (including 81 patients), and 1 case report. Treatment was exclusively targeting Chlamydophila psittaci (CP), using doxycycline in all but 2 studies. The median follow-up for these studies was 25 months, and both CP-positive as well as CP-negative patients responded. Complete remission was achieved in 23 patients (18%), 36 (27%) had a partial remission, 55 (42%) had stable disease, and 8 patients (6%) had progressive disease accounting for an overall response rate of 45%. In the largest study, a better response was suggested in CP-positive patients. By contrast, only scattered reports could be found for other non-GI localizations, allowing no conclusion about the benefit of antibiotic therapy and probably resulting in a publication bias toward positive cases. Based on these results, antibiotic therapy using doxycycline appears to be a reasonable first-line therapy for patients with OAML. Antibiotics, however, remain experimental for the time being in patients with other non-GI MALT lymphomas. Further preclinical studies as well as large-scale therapeutic trials are warranted to define the role of antibiotic therapy in such patients.

Primary bladder lymphoma: management and outcome of 12 patients with a review of the literature

Primary bladder non-Hodgkin's lymphoma (NHL) is rare. Optimal management remains controversial. Using the Scotland and Newcastle lymphoma group database, 12 patients with primary bladder lymphoma were identified between 1980 and 2001, the largest single group of patients available to date. Histology and immunocytochemistry was reviewed in 9 of the 12 cases. Six cases were low-grade extranodal marginal zone lymphoma, 4 diffuse large B-cell lymphoma, one an ALK 1 positive anaplastic large cell lymphoma (ALKoma) and one a low-grade lymphoma unspecified. Two patients (low-grade NHL) were treated with oral antibiotics (n=1) or diathermy (n=1) alone with complete resolution of disease. One patient with high-grade NHL gained complete remission without conventional therapy. Nine patients were treated with single or combined modality surgery, chemotherapy and/or radiotherapy. Overall survival was 75%, mean follow up of 4.8 (range 1-10) years. A review of 88 additional cases in the literature support the findings that primary bladder lymphoma is associated with a good prognosis. Patients with low-grade extranodal marginal zone lymphoma may respond well to simple therapies. Patients with diffuse large B-cell lymphoma respond well to first-line chemotherapy regimens. Ureteric obstruction and acute renal failure are serious complications. Repeat cystoscopy is mandatory for follow-up.

Role of cytochrome P450 reductase in nitrofurantoin-induced redox cycling and cytotoxicity

The one-electron reduction of redox-active chemotherapeutic agents generates highly toxic radical anions and reactive oxygen intermediates (ROI). A major enzyme catalyzing this process is cytochrome P450 reductase. Because many tumor cells highly express this enzyme, redox cycling of chemotherapeutic agents in these cells may confer selective antitumor activity. Nitrofurantoin is a commonly used redox-active antibiotic that possesses antitumor activity. In the present studies we determined whether nitrofurantoin redox cycling is correlated with cytochrome P450 reductase activity and cytotoxicity in a variety of cell lines. Recombinant cytochrome P450 reductase was found to support redox cycling of nitrofurantoin and to generate superoxide anion, hydrogen peroxide, and, in the presence of redox-active iron, hydroxyl radicals. This activity was NADPH dependent and inhibitable by diphenyleneiodonium, indicating a requirement for the flavin cofactors in the reductase. Nitrofurantoin-induced redox cycling was next analyzed in different cell lines varying in cytochrome P450 reductase activity including Chinese hamster ovary cells (CHO-OR) constructed to overexpress the enzyme. Nitrofurantoin-induced hydrogen peroxide production was 16-fold greater in lysates from CHO-OR cells than from control CHO cells. A strong correlation between cytochrome P450 reductase activity and nitrofurantoin-induced redox cycling among the cell lines was found. Unexpectedly, no correlation between nitrofurantoin-induced ROI production and cytotoxicity was observed. These data indicate that nitrofurantoin-induced redox cycling and subsequent generation of ROI are not sufficient to mediate cytotoxicity and that cytochrome P450 reductase is not a determinant of sensitivity to redox-active chemotherapeutic agents.

Infectious agents in mucosa-associated lymphoid tissue-type lymphomas: pathogenic role and therapeutic perspectives

Mucosa-associated lymphoid tissue (MALT) lymphoma probably constitutes the best in vivo model showing how complex interplay between B lymphocytes and the surrounding microenvironment may lead to a neoplastic disorder. After the seminal discovery of the pathogenic association between Helicobacter pylori and gastric MALT lymphomas, evidence suggests the possible involvement of other infectious agents in the development of MALT lymphomas arising at different body sites. Although several other bacteria (Borrelia burgdorferi, Campylobacter jejuni, and Chlamydia psittaci) and viruses (Hepatitis C virus) seem to play a role in lymphomas presenting at different locations, a possible common pathogenic mechanism is emerging. Several lines of evidence suggest that different infectious agents might provide a chronic antigenic stimulation that elicits host immune responses able to promote clonal B-cell expansion. This model is also substantiated by the increasing number of patients with MALT lymphomas who exhibit objective clinical responses after antimicrobial therapy. A multidisciplinary approach is critical to better understand the complex etiopathogenesis of MALT lymphomas with the final goal to dissect the clinicopathologic heterogeneity of these disorders and design more tailored preventive and therapeutic approaches.

Nongastric mucosa-associated lymphoid tissue lymphomas

Nongastric mucosa-associated lymphoid tissue (MALT)-derived lymphomas arise from various extranodal locations and are usually related to a particular pathogenesis with a possible external (environmental or autoimmune) event inducing the disease. We reviewed 165 patients with nongastric MALT lymphoma among the 243 patients with MALT lymphoma in our database and reviewed reports in the literature to analyze the clinical features of nongastric MALT lymphomas. The site of clinical presentation was related to the lymphoma location and was usually indolent. Dissemination of the disease at diagnosis was noticed in 48% of cases because of the involvement of multiple mucosal sites (48%) or because of a nonmucosal site involvement such as bone marrow, spleen, or liver (52%). With a median follow-up of 4 years, the estimated 5-year overall survival and 5-year freedom-from-progression rates were 89% and 50%, respectively, without any difference between patients with localized or disseminated disease or among different locations. Treatment recommendations for localized disease are based on surgery, local therapy, or chlorambucil. For disseminated disease, treatment recommendations include chemotherapy with fludarabine or chlorambucil or chemotherapy with CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) in cases of large tumor mass