Diagnosis Of Mucosa-associated Lymphoid Tissue Lymphoma Research Articles

Massive bleeding in small intestinal mucosa-associated lymphoid tissue lymphoma associated with COVID-19 infection: a case report

Abstract The increased risk of mucosa-associated lymphoid tissue (MALT) lymphoma is closely associated with chronic antigenic stimulation, with infection being the most common cause of recurrence. Lesions are usually associated with the gastrointestinal tract, and the involvement of small intestinal is rare. Recent studies have established a close relationship between novel coronavirus 2019 (COVID-19) and the occurrence and progression of various diseases. This article presents a rare case of a small intestinal MALT lymphoma. The patient was initially admitted with COVID-19 pneumonia and subsequently developed gastrointestinal bleeding during hospitalization. Medical and endoscopic treatments were ineffective, and an emergency exploratory laparotomy was performed. The affected segment of the small intestine was excised, and a pathological biopsy confirmed the diagnosis of MALT lymphoma. This case underscores the significance of raising clinical awareness of this condition among health care professionals.

P-20 Primary hyperparathyroidism associated with maltoma of the thyroid gland: imaging challenges

Abstract Introduction Primary hyperparathyroidism (PHP) and malignancies are the most common causes of hypercalcemia. Nevertheless, PHP might be observed in coexisting with malignancies. We aimed to present a patient who underwent surgery for PHP and was diagnosed with thyroid MALToma. Clinical Case A 65-year-old female presented with fatigue for one year. The patient's medical history was unremarkable. On examination, thyroid gland was non-palpable. On laboratory, serum calcium (Ca), phosphorus (P) and parathormone (PTH) levels were 11 mg/dL (R: 8.8-10.6), 2.4 mg/dL (R: 2.5-4.5) and 157 pg/mL, respectively; vitamin-D was 23.63 µg/L and increased urinary Ca (400 mg per-day). She was euthyroid, and thyroid antibody elevated. Ultrasound (US) revealed multiple hypoechoic areas and a lesion (18×14 mm) in the vicinity of inferior right thyroid gland. Parathyroid scintigraphy revealed significant increase of metabolic activity posterior to the right lobe of the thyroid. She underwent right thyroid lobectomy thyroidectomy. Pathology revealed mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid. No parathyroid lesion noted. Then she was referred to our clinic. US revealed hypoechoic areas at remaining thyroid with no extra finding. We performed tru-cut biopsy from thyroid lesion. On immunochemistry, lymphoid cells were diffusely immunoreactive for CD3, CD5, CD20 and CD43 in the ymphocytes. Ki-67 index was 40%. Hence, the diagnosis of MALT lymphoma of the thyroid gland in the background of Hashimoto's thyroiditis. PTH staining of patient's previous pathology specimen was unremarkable. Pretreatment baseline 18F-flurodeoxyglucose PET/CT (FDG) revealed increased uptake (SUVmax: 5.1) in hypodense nodular structure in the posterior left lobe of the thyroid gland (Figure 1). FDG was suggestive of stage IE. Mild 18F-FCH uptake was observed suspected as parathyroid lesion next to the inferior left lobe. 4D-CT showed similar results. All imaging methods and we examined patient via US that revealed hypoechoic lesion with polar blood supply in the left lobe inferior (parathyroid adenoma). The patient were under rituximab 375 mg/m2 per week for 4 cycles. At the end of treatment, there were no sign of residual disease. Reoperation has not been planned due to the improvement of the patient's symptoms, and lymphoma with indolent course. Conclusion 10% of PHP cases may have a concomitant malignancy, while association with lymphoma is even rarer. MALT lymphoma of the thyroid gland is a rare malignancy with an indolent course. The combination of these two rare conditions hard to orchestrate. As in our case, detection of parathyroid lesions becomes more difficult in the background of a low grade lymphoma. Indolent lymphomas have limited sensitivity with FDG. FCH could be more sensitive for discriminating parathyroid lesions and indolent lymphomas. It may be useful to confirm the localization of the PHP in such cases using multiple techniques involving FCH.Figure 1.Pre-treatment avid FCH uptake (A, B) and mild FDG uptake (C, D) related with thyroid MALToma; post-treatment complete remission shown in FDG (E, F); highly vascular paratracheal lesion at 4D-CT (G, H asterixis), the same lesion with mild FCH uptake (I-N arrows) and the same lesion with hypoechoic sonographic appearance evaluated as parathyroid adenoma (O arrow).

Risk factors analysis and establishment of predictive nomogram of extranodal B-cell lymphoma of mucosal-associated lymphoid tissue

PurposeThe role of radiation therapy in mucosa-associated lymphoid tissue (MALT) lymphoma is poorly defined. The objective of this study was to explore the factors associated with the performance of radiotherapy and to assess its prognostic impact in patients with MALT lymphoma. Patients and methodsPatients with MALT lymphoma diagnosed between 1992 and 2017 were identified in the US Surveillance, Epidemiology, and End Results database (SEER). Factors associated with the delivery of radiotherapy were assessed by chi-square test. Overall survival (OS) and lymphoma-specific survival (LSS) were compared between patients with and without radiotherapy, using Cox proportional hazard regression models, in patients with early stage as well as those with advanced stage. ResultsOf the 10,344 patients identified with a diagnosis of MALT lymphoma, 33.6% had received radiotherapy; this rate was 38.9% for stage I/II patients and 12.0% for stage III/IV patients, respectively. Older patients and those who already received primary surgery or chemotherapy had a significantly lower rate of receiving radiotherapy, regardless of lymphoma stage. After univariate and multivariate analysis, radiotherapy was associated with improved OS and LSS in patients with stage I/II (HR=0.71 [0.65–0.78]) and (HR=0.66 [0.59–0.74]), respectively, but not in patients with stage III/IV (HR=1.01 [0.80–1.26]) and (HR=0.93 [0.67–1.29]). The nomogram built from the significant prognostic factors associated with overall survival of stage I/II patients had a good concordance (C-index=0.749±0.002). ConclusionThis cohort study shows that radiotherapy is significantly associated with a better prognosis in patients with early but not advanced MALT lymphoma. Prospective studies are needed to confirm the prognostic impact of radiotherapy in patients with MALT lymphoma.

Proteogenomic analysis of the autoreactive B cell repertoire in blood and tissues of patients with Sjögren’s syndrome

ObjectiveTo comparatively analyse the aberrant affinity maturation of the antinuclear and rheumatoid factor (RF) B cell repertoires in blood and tissues of patients with Sjögren’s syndrome (SjS) using an integrated...

Primary oral mucosa-associated lymphoid tissue (MALT) lymphoma in patient with monoclonale gammopathy: a rare case report

BackgroundMonoclonal gammopathy is a biological reality encountered in approximately 1% of the general population. In the absence of clinical and biological signs, it is considered of undetermined significance; however, it can be a biological signature of a monoclonal lymphocytic or plasma-cell proliferation. Their localisation to the oral mucosa remains rare and difficult to diagnose, particularly in indolent forms that escape imaging techniques.Case presentationHere, we report the case of a 73-year-old woman with a history of IgM kappa gammopathy followed for 13 years. The patient did not have a chronic infection or an autoimmune disease, and all the biological investigations and radiological explorations were unremarkable during this period. The discovery of a submucosal nodule in the cheek led to the diagnosis of MALT lymphoma and regression of half of the IgM kappa level after resection. The review of the literature shows the dominance of clinical signs (i.e., a mass or swelling) in the diagnosis of primary MALT lymphomas of the oral cavity after surgical resection.ConclusionsOur case illustrates the role of examination of the oral cavity in the context of a monoclonal gammopathy. The absence of clinical and radiological evidence in favor of lymphoplasmacytic proliferation, does not exclude a primary indolent MALT lymphoma of the oral mucosa.

Primary Pulmonary Mucosa-associated Lymphoid Tissue Lymphoma with the High Expression of IgG4.

This is the first report describing primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma with the high expression of IgG4. The histological findings were compatible with the diagnostic criteria for MALT lymphoma and IgG4-related respiratory disease (IgG4-RRD). An unfixed sample for Southern blotting was not obtained since computed tomography findings showed multiple lung cysts, which is rare in patients with MALT lymphoma. However, polymerase chain reaction using paraffin sections showed the clonality of the immunoglobulin heavy chain variable region gene rearrangement, confirming a diagnosis of MALT lymphoma. This is an instructive case in which primary pulmonary MALT lymphoma was histologically compatible with IgG4-RRD.

Characterization of Second Primary Malignancies in Mucosa-Associated Lymphoid Tissue Lymphomas: A SEER Database Interrogation.

Introduction: Second primary malignancies (SPMs) are long-term complications in cancer survivors. Mucosa-associated lymphoid tissue (MALT) lymphomas are indolent extra-nodal marginal zone lymphomas, the majority of which typically have long-term survival. In this study, we investigated the incidence and pattern of SPMs in adult patients diagnosed with MALT lymphomas between January 2000 and December 2016. Methods: Using the SEER-18 database and multiple primary standardized incidence ratio (MP-SIR) session of SEER stat software for statistical analysis, we assessed SPMs in MALT lymphomas. Results: During this time, a total of 12,500 cases of MALT lymphomas were diagnosed, of which 1466 patients developed 1626 SPMs (O/E ratio: 1.48, 95% CI:1.41-1.55, P<.001). The median latency period for development of SPMs was 54 months (range 6-201 months). Secondary non-Hodgkin lymphomas, as defined by SEER as distinct from the primary lymphoma, was the most common SPM with 299 cases, followed by lung cancer (O/E ratio: 6.15, 95% CI:5.47-6.89, P<.0001). There were 898 SPMs that developed between 6- 59 months (O/E ratio: 1.47, 95% CI:1.37-1.57, P<.0001) and 728 after 60 months latency (O/E ratio: 1.5, 95% CI:1.39-1.61, P<.0001) after diagnosis of the primary MALT lymphomas. An increased incidence of both solid and hematologic cancers occurred in patients as early as 6 months after diagnosis of MALT lymphoma. Conclusion: These findings indicate that despite the indolent nature of most MALT lymphomas, there is an increased risk for SPMs warranting long-term follow up.

Primary mucosa-associated lymphoid tissue lymphoma in the midbrain: A case report

BACKGROUNDPrimary non-dural central nervous system mucosa-associated lymphoid tissue (MALT) lymphoma is a rare indolent B-cell lymphoma, with only a few reported cases worldwide.CASE SUMMARYA 33-year-old man presented with a 5-mo history of left blepharoptosis and a 4-mo history of right limb numbness and weakness. Magnetic resonance imaging showed a significantly enhanced mass in the left midbrain. Subsequent positron emission tomography revealed that the lesion had increased glucose uptake. A stereotactic robotic biopsy supported a diagnosis of MALT lymphoma. Then he was treated with radiation therapy (30Gy/15F), which resulted in complete remission. We also review the literature on brain parenchymal-based MALT lymphoma, including the clinical presentation, treatment options, and outcomes.CONCLUSIONAlthough there is no consensus on the optimal treatment for this rare disease, patients can respond well when treated with radiotherapy alone.

No evidence for a pathogen associated with pulmonary MALT lymphoma: a metagenomics investigation

Mucosa-associated lymphoid tissue (MALT) lymphoma is generally associated with chronic antigen stimulation: auto-antigens or of microbial origin. Only one study suggested association between Achromobacter xylosoxidans and pulmonary MALT lymphoma. We aimed to investigate the presence of virus or any infectious agents in pulmonary MALT lymphoma by using metagenomic next-generation sequencing (mNGS).All lung samples were centrally reviewed. The t(11;18) (q21;q21) was evaluated by FISH analysis. The snap frozen large lung biopsies were analyzed by mNGS. After lung biopsies homogenization total nucleic acids (RNA and DNA) were extracted, amplified and classified according to their taxonomic assignment, after exclusion of host DNA.We included 13 samples from pulmonary MALT lymphoma (mean age: 60.3 years, 7 women, 3 with auto-immune background) and 10 controls. The diagnosis of MALT lymphoma was confirmed for the 13 samples, 3 showed API2-MALT1 translocation (23%). No evidence of the presence of a specific pathogen was clearly identified in the group of patients with pulmonary MALT lymphoma. We identifiedA. xylosoxidans sequence in 4/13 patients and in 4/10 controls.This study did not find evidence for a DNA or RNA virus, a fungi, a parasite or a bacteria associated with pulmonary MALT lymphoma either in the stroma or in tumor cells.

Duodenal Mucosa-associated Lymphoid Tissue Lymphoma Treated with Chemotherapy

Mucosa-associated lymphoid tissue (MALT) lymphomas most commonly occur in the stomach and rarely in the duodenum. Gastric MALT lymphoma is usually associated with &lt;i&gt;Helicobacter pylori&lt;/i&gt; (&lt;i&gt;H. pylori&lt;/i&gt;) infection that may be cured by eradication. However, duodenal MALT lymphoma is not associated with &lt;i&gt;H. pylori&lt;/i&gt; infection. Moreover, the pathophysiology and treatment methods for duodenal MALT lymphoma have not yet been established because the disease is rare. Here, we report a case of duodenal MALT lymphoma. A 58-year-old man was treated for a refractory duodenal ulcer. Based on repeated biopsy, a diagnosis of MALT lymphoma was made. The patient achieved complete remission after chemotherapy and was followed up without recurrence for three years.

Transformed mucosa-associated lymphoid tissue lymphomas: A single institution retrospective study including polymerase chain reaction-based clonality analysis.

Given the lack of consistent data regarding the clinico‐pathological features and clonal lymphomagenesis of patients with mucosa‐associated lymphoid tissue (MALT) lymphoma and histological transformation (HT), we have systematically analysed 379 patients (32% gastric, 68% extra‐gastric; median follow‐up 52 months) diagnosed with HT at the Medical University Vienna 1999–2017, and reassessed tissues of identified patients by polymerase chain reaction (PCR)‐based clonality analysis. HT was documented in 12/379 patients (3·2%) and occurred at a median time of 22 months (range; 6–202 months) after diagnosis of MALT lymphoma. By PCR‐based clonality analysis, we detected a clear‐cut clonal relationship of MALT lymphoma and diffuse large B‐cell lymphoma (DLBCL) in 8 of 11 analysed cases proving that the large majority of DLBCL following MALT lymphoma are clonally‐related and constitute a real transformation. Interestingly, HT occurred within the first 2·5 years after diagnosis in patients with clonal relationship, whereas time to aggressive lymphoma was longer in patients identified as clonally‐unrelated (most likely secondary) lymphoma (82–202 months), suggesting that HT is an early event in this disease. Survival of patients with HT was poor with 6/12 dying at 1·5–33 months after HT, however, patients with localized gastric transformation had a superior outcome with only 1/6 dying due to progression of lymphoma.

Pre-malignant signs of gastric MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common type of extra-nodal non-Hodgkin lymphoma, which mostly involves the stomach. The clinical suspicion and diagnosis are often challenging because of the lack of specific symptoms and conventional endoscopic findings. Three magnifying endoscopic signs of the gastric mucosa have been described as highly specific to the diagnosis of MALT lymphoma, such as (i) tree-like appearance of the microvessels; (ii) non-structural area; and (iii) ballooning crypt pattern. We report the case of a middle-aged woman in which these signs appeared chronologically over a period of 2 years, showing the association of the sequence of the endoscopic findings and the final histological diagnosis of gastric MALT lymphoma.

CHRONIC PARENCHYMAL INFILTRATION FROM MALT LYMPHOMA: DIAGNOSIS BY ENDOBRONCHIAL ULTRASOUND

SESSION TITLE: Lung Pathology 2 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Mucosa-associated lymphoid tissue (MALT) lymphoma is a rare cause of pulmonary infiltrate. The lung accounts for only 4% of all extra-nodal marginal zone MALT lymphomas [1] and presents mostly as an incidental finding or with non-specific symptoms. CASE PRESENTATION: A previously healthy 59-year-old man presented with chest pain in 2013. A chest radiograph noted bilateral infrahiliar masses. Computed tomography (CT) of the chest showed bilateral lung consolidations (Figure 1). He was treated with antibiotics and lost to follow up. Five years later the patient presented with transient stroke-like symptoms and a chest x-ray showed a persistent infiltrate. CT chest noted large bibasilar consolidations with air bronchograms and dilated bronchi (Figure 2). These infiltrates were hypermetabolic on positron emission tomography (PET) with a maximum standardized uptake value (SUV) of 6.4. The patient underwent bronchoscopy with endobronchial ultrasound guided transbronchial 19 gauge needle aspiration (EBUS-TBNA) of the consolidative lesions. Immunohistochemistry and flow cytometry confirmed a diagnosis of MALT lymphoma. He was referred to oncology and initiated on rituximab and bendamustine. DISCUSSION: MALT lymphoma of the lung is a relatively rare disease that has been associated with chronic antigen stimulation in the context of infection, autoimmune disease and toxic exposure. The clinical presentation and radiographic findings are varied and can be mistaken for more common entities. Lesions are usually bilateral and often have associated air bronchograms and bronchiectasis [2]. The disease usually has an indolent course with a favorable prognosis. In most reported cases, diagnosis was achieved with open lung or CT-guided biopsy. The role of EBUS-TBNA for pulmonary MALT lymphoma has been previously described in mediastinal lymphadenopathy and was found to be useful [3]. To our knowledge, this is the first case of EBUS-TBNA of lung infiltrates to diagnose this condition. CONCLUSIONS: MALT lymphoma is a rare lung malignancy that should be considered in the differential diagnosis of non-resolving pulmonary lesions. Minimally invasive approaches such as bronchoscopy and EBUS-TBNA can retrieve sufficient tissue for diagnosis. Reference #1: Schreuder MI, Van den Brand M, Hebeda K, et al. Novel developments in the pathogenesis and diagnosis of extranodal marginal zone lymphoma. J Hemathopatol. 2017; 10: 91-107. Reference #2: Wislez M, Cadranel J, Antoine M, et al. Lymphoma of pulmonary mucosa-associated lymphoid tissue: CT scan findings and pathological correlations. Eur Respir J. 1999; 14: 423-429. Reference #3: Nunez AL, Jhala NC, Carroll AJ, et al. Endoscopic ultrasound and endobronchial ultrasound-guided fine-needle aspiration of deep-seated lymphadenopathy: Analysis of 1338 cases. Cytojournal. 2012;9:14. DISCLOSURES: Consultant relationship with Boston Scientific Please note: $1-$1000 Added 03/02/2018 by Alex Chee, source=Web Response, value=Consulting fee No relevant relationships by Isabel Londono Marulanda, source=Web Response Consultant relationship with Boston Scientific Please note: $5001 - $20000 Added 03/04/2018 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with Olympus Please note: $5001 - $20000 Added 03/04/2018 by Adnan Majid, source=Web Response, value=Consulting fee No relevant relationships by Mihir Parikh, source=Web Response No relevant relationships by Andrew Schissler, source=Web Response

Cellular-level characterization of B cells infiltrating pulmonary MALT lymphoma tissues.

Mucosa-associated lymphoid tissue (MALT) lymphoma mainly consists of three types of tumor B cells, small (centrocyte-like), scattered large transformed, and intraepithelial. However, it is difficult to differentiate tumor B cells from reactive B cells at the cellular level. We examined five cases of API2-MALT1 fusion-positive MALT lymphoma of the lung. A single paraffin section for each case was subjected to sequential retrieval of whole-slide imaging (WSI) data of hematoxylin and eosin (HE) staining, immunofluorescence staining for CD79a, and fluorescence in situ hybridization (FISH) for the MALT1 split. We counted the number of MALT1 split-positive or MALT1 split-negative cells among CD79a-positive cells. The MALT1 split was detected in 59, 46, and 76% of small, large, and intraepithelial B cells, respectively. A review of the HE-WSI data showed that cytomorphological distinction between the MALT1 split-positive and MALT1 split-negative B cells was virtually impossible. None of CD79a-negative lymphoid cells, epithelial cells, and microvascular endothelial cells was positive for MALT1 splits. As API2-MALT1 fusion is an early and critical event in the lymphomatogenesis, our findings are best interpreted as that a considerable number of B cells, either small, large, or intraepithelial, are reactive cells and that it is difficult to distinguish cytomorphologically between tumor B cells and reactive B cells. These findings suggest that the tumor architecture may be the central factor for making a correct histopathological diagnosis of MALT lymphoma. The sequential WSI of HE staining, immunofluorescence staining, and FISH as described here is a useful tool for pathological analysis at the cellular level.

A Rare Case of Mucosa-Associated Lymphoma of the Colon

Case Report: A 73-year-old man presented to the emergency room with complains of bright red per rectum associated with lower abdominal pain. He had generalized weakness with decreased oral intake for 1 month prior to admission. Physical exam was significant for mild tenderness to palpation in the right upper abdomen with no guarding and rebound tenderness. On colonoscopy, there was a 2-cm polypoid fold at the hepatic flexure. Biopsy of the lesion showed mixed lymphoid infiltrate consisting of atypical lymphoid cells with pale cytoplasm and irregular nuclei. Immunohistochemistry was positive for CD 20 and negative for CD 5 and cyclin D1, confirming the diagnosis of marginal zone B-cell lymphoma. The tumor was resected on subsequent colonoscopy. Discussion: Mucosa-associated lymphoid tissue (MALT) is present in the bowel as Payer’s patches. Interestingly, the most common site of presentation of gastrointestinal MALT lymphomas is the stomach, which is devoid of Payer’s patches. Chronic infection with H. pylori causes development of MALT lymphomas in the stomach. Colonic MALT lymphomas are very rare, accounting for 2.5% of the total gastrointestinal MALT lymphomas; their association with H. pylori infection is not clear. The diagnosis of MALT lymphoma is made by histopathology. An estimated 65% of the cases have reported cure of gastric MALT lymphomas after eradication of H. pylori bacteria in the stomach. Because of low incidence, the treatment of MALT lymphomas of the colon is still not well defined. Surgery has been shown to be the treatment of choice for localized lesions. However, MALT lymphomas have shown a propensity to remain localized and be confined to the regional lymph nodes for a long time, which raises the question whether surgery with its associated risks is appropriate. Another alternative is radiotherapy, which has shown to provide 99% response rate in both gastric and thyroid MALT lymphomas. Close follow-up is required for colonic MALT lymphoma because of limited knowledge on recurrence and prognosis. The gross appearance of lymphoma on colonoscopy also varies considerably and we would recommend biopsies of any abnormal mucosal lesion noted on surveillance colonoscopy.Figure 1

MALT lymphoma of the small bowel with protein-losing enteropathy

Mucosa-associated lymphoid tissue (MALT) lymphoma usually arises from chronic inflammation. We herein report a case of small intestinal MALT lymphoma with protein-losing enteropathy (PLE). A 73-year-old woman presented with lower leg edema and severe hypoalbuminemia. She had a medical history of pylorus-preserving pancreaticoduodenectomy with Billroth II reconstruction. Oral and anal route double-balloon enteroscopies revealed irregular nodular mucosal lesions with erosion extending from the jejunum to terminal ileum. Histopathological evaluation of the biopsied mucosa showed proliferation of small-to-medium-sized lambda light chain-restricted B cells. Plasmacytic differentiation and lymphoepithelial lesions were present, leading to the diagnosis of MALT lymphoma. Tc-99m albumin scintigraphy indicated tracer exudation in the small bowel, suggesting the presence of PLE. Combination immunochemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) regimen improved both MALT lymphoma and PLE, whereas rituximab monotherapy was not successful. This case is considered to be common type of MALT lymphoma at an uncommon site and is distinct from immunoproliferative small intestinal disease (IPSID). To our knowledge, this is the first case of non-IPSID-type small intestinal MALT lymphoma complicated by PLE. Gastrointestinal reconstruction may be responsible for underlying chronic inflammation via small intestinal bacterial overgrowth.

Combination of MALT lymphoma of the nasopharynx and the rectum: a case report

Mucosa –associated lymphoid tissue (MALT) is an extra-nodal marginal zone B cell lymphoma, it accounts for about 7-8% of all non hodgkinian lymphomas. It occurs most frequently in the stomach (70% of the cases), but can also occur on non gastric tissue especially the salivary glands, orbit, thyroid, lungs. However, colo-rectal and nasopharyngeal involvements are extremely rare. We report the case of a combination of these unusual locations in a 51-years-old patient in whom MALT lymphoma was diagnosed in 2006. The patient had rectal bleeding. Colonoscopy has shown the presence of large ulcerated folds of the rectum. Pathological and immunohistochemical study confirmed the diagnosis of MALT lymphoma. No extra intestinal involvement was found on the staging evaluation. The patient had a pelvic radiation at the dose of 40 Gy with endoscopic and histological remission. Eight months after the end of treatment, clinical examination showed an oropharyngeal mass. The computed tomography revealed a thickening of the posterior nasopaharyngel wall extended to the oropharynx. The diagnosis of MALT lymphoma was confirmed by the biopsy. The patient had radiotherapy on the Wadayer ring at the dose of 44 Gy. Currently, five years after the end of treatment, the patient is on complete remission.

Value of multidetector computed tomography in the diagnosis of mucosa-associated lymphoid tissue-lymphomas in the parotid gland: A case report and review of the literature

The present study aimed to review the multidetector computed tomography (MDCT) imaging features of eight mucosa-associated lymphoid tissue (MALT)-lymphoma cases of the parotid gland and to explore the diagnostic value of MDCT. A total of eight patients with pathologically confirmed MALT-lymphomas of the parotid gland underwent pre-operative MDCT plain and dual-phase scans. The changes in the CT values and enhancement patterns of the tumors were assessed. Quantitative analysis was performed to determine the CT value changes of the tumors in the various enhanced phases compared with the plain scan. The MALT-lymphomas of the parotid gland exhibited even density isodense or hyperdense nodules, with occasional calcification and necrosis. The dual-phase scan of the MALT-lymphomas revealed a pattern of lower or moderate enhancement, circumambient enhancement or delayed enhancement. The MALT-lymphomas were closely associated with Sjögre’s syndrome and demonstrated malignant features and isodense or hyperdense nodules and lower or moderate enhancement on the CT scans.

Malignant lymphoma of mucosa-associated lymphoid tissue involving the renal pelvis and the entire ureter: A case report

Mucosa-associated lymphoid tissue (MALT) lymphoma occurs in various sites, but rarely in the urinary tract. Imaging studies of a 69-year-old male revealed a left hydronephrosis and diffuse thickening of the renal pelvic and upper ureteral wall. Retrograde pyelography revealed a narrowing in this region, and brush cytology specimens contained atypical cells. As the lesion was considered to be malignant, surgical excision was performed. Histological analysis revealed an intense lymphoid infiltrate mainly consisting of B cells. The immunohistochemistry results demonstrated that the lesion was positive for CD20 and CD79a and negative for CD5 and cyclin D1. These findings led to a diagnosis of MALT lymphoma. Pathological exploration disclosed a focally dense invasion of lymphoma cells into not only the renal pelvis, but the whole ureteral wall and surrounding tissue; therefore, the patient underwent eight courses of rituximab treatment. Diffuse invasion of lymphoma cells into the whole ureter was rarely observed. Since the surgery, the patient has survived for 78 months without evidence of a recurrence of lymphoma.

A Definitive Diagnosis of Mucosa-associated Lymphoid Tissue Lymphoma Made at a Second Biopsy

A case of mucosa-associated lymphoid tissue (MALT) lymphoma, the most frequent of the various conjunctival lymphoproliferative disorders, in which the initial biopsy was inconclusive but the second biopsy provided a definitive diagnosis, is reported. A 26-year-old woman with a 3-month history of bilateral conjunctival swelling was referred by a local physician for suspected MALT lymphoma. A salmon-pink elastic swelling was found to involve both eyes and to extend from the lower palpebral conjunctiva to the bulbar conjunctiva. Tonsillar swelling was also found, and ophthalmologic (left eye) and otolaryngologic biopsies were therefore performed simultaneously under general anesthesia. The otolaryngologic diagnosis was chronic tonsillitis. Light microscope examination of the conjunctival tissue showed proliferation of lymphocytes and small aggregates of small to medium-sized atypical lymphocytes. On immunohistochemical studies, atypical lymphocytes were positive for CD20 and CD79a, but differentiation to plasmacytes was not prominent, and neither Dutcher bodies nor evidence of immunoglobulin light chain restriction was found. The results were not incompatible with MALT lymphoma but were not definitive. A second biopsy of the right eye was therefore performed 3 months later. Staining with hematoxylin and eosin showed proliferation of small lymphocytes and monocytoid B cells and differentiation to plasmacytes. The hyperplastic cells were positive for CD19, CD79a, and CD20, and their cytoplasm were positive for Bcl-2 and slightly positive for Bcl-6. Cells positive for CD38 were noted where differentiation to plasmacytes and immunoglobulin light chain κ restriction was evident on immunohistochemical studies and in situ hybridization. The Ki-67-positivity rate was approximately 5%. The results of paraffin-embedded tissue section fluorescence in situ hybridization were negative for MALT-1 (18q21). A diagnosis of MALT lymphoma was made, and treatment with rituximab was started. Few findings lead directly to a definitive diagnosis of MALT lymphoma, and its differential diagnosis from benign lymphoproliferative disorders is difficult. In the present case definitive diagnosis was possible only after a second biopsy. This case suggests repeated biopsy may be necessary when a single biopsy is not definitive.