Primary non-Hodgkin's lymphoma and pseudolymphoma of lung: a study of 161 patients

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.

Clinical features, natural history and outcomes of pseudolymphoma of liver: A case-series and systematic review

BACKGROUND

Pseudolymphoma is a rare, benign, nonspecific condition that forms a mass-like lesion characterized by the proliferation of non-neoplastic lymphocytes. Lacking of specific clinical symptoms, serological markers, and imaging features, the diagnosis is difficult. We reporte five cases of hepatic pseudolymphoma and provide a systematic review of existing literatures to improve our understanding of this rare liver disease.

METHODS

We followed-up five cases of hepatic pseudolymphoma in West China Hospital from January 2002 to January 2022. We also summarized the cases of hepatic pseudolymphoma from January 1981 to December 2021 through the PubMed database and comprehensively analyzed the characteristics of the cases.

RESULTS

The pathologic features of the five cases were characterized by benign lymphoid tissue hyperplasia, lymphoid follicle formation, and a polarized germinal center. Immunohistochemistry, in situ hybridization, and gene rearrangement revealed non-malignant lymphoma. Besides, a total of 116 cases have been reported in the PubMed database from 1981 to 2021. The incidence of hepatic pseudolymphoma is higher in middle-aged and elderly women and has been reported more frequently in Asia. All cases were pathologically diagnosed, among which 85.95% of the patients were treated by surgery.

CONCLUSIONS

Hepatic pseudolymphoma is an extremely rare benign disease, mainly in middle-aged and elderly women. Without distinctive clinical and imaging characteristics, pathological diagnosis is the highly reliable method at present. Thus, in the absence of risk factors for a primary liver tumor or metastatic tumor in middle-aged and elderly women, the possibility of pseudolymphoma should be considered to avoid extensive treatments.

Primary pulmonary mucosa-associated lymphoid tissue lymphoma: A case report

Primary pulmonary lymphoma (PPL) is a rare entity with the most common presentation as mediastinal lymphadenopathy. The most common form of PPL is Mucosa-Associated Lymphoid Tissue Lymphoma (MALToma) which is an extranodal B-cell lymphoma originating from the mucosal layers involving different organs such as the gastrointestinal tract as well as the lung. Herein, we present a case of a 51-year-old woman with progressive dyspnea for 6 months and no prior medical history. The computed tomography (CT scan) revealed bilateral multifocal consolidation and ground-glass opacities as well as interlobular septal thickening. Bronchoscopy was normal and CT-guided biopsy of lung consolidations was conclusive of MALToma. Complete extrapulmonary evaluations inducing bone marrow aspiration were unremarkable. The primary pulmonary MALToma is an extremely rare entity that presents with non-specific symptoms and a wide variety of CT findings such as mediastinal, hilar lymphadenopathy, and single or multiple lung nodules ranging from 2 to 8 cm. the disease has a favorable prognosis, so prompt diagnosis is essential.

Surgery and chemotherapy cannot improve the survival of patients with early-stage mucosa-associated lymphoid tissue derived primary pulmonary lymphoma

Background

To date, there is no treatment consensus on mucosa-associated lymphoid tissue (MALT) derived primary pulmonary lymphoma (PPL).

Methods

We identified patients with early-stage MALT-type PPL from the National Cancer Institute’s Surveillance, Epidemiology, and End Results program database. The patients were divided into four groups according to treatment modalities: None of surgery or chemotherapy (None) group, Surgery alone group, Chemotherapy alone (Chemo alone) group, and Surgery plus chemotherapy (Surgery + chemo) group. Overall survival (OS) and cancer-specific survival (CSS) were study endpoints. We performed Cox regression analyses, propensity score-matched analyses (PSM) and Kaplan-Meier (KM) survival curves to compare the survival among different groups.

Results

A total of 953 patients were included in our analysis with 302, 403, 175, and 73 cases in the None, Surgery alone, Chemo alone, and Surgery + chemo groups, respectively. In this cohort, the estimated 3-year, 5-year and 10-year OS rates were 86.95%, 78.91%, and 55.89%, respectively. Meanwhile, the estimated 3-year, 5-year and 10-year CSS rates were 96.71%, 93.73%, and 86.84%, respectively. Multivariate Cox regression analyses demonstrated that increasing age, tumors located in the lower lobe, and stage II were significant predictors of poorer OS while increasing age and tumors located in the bilateral lungs were associated with lower CSS. After PSM analyses, the KM survival curves showed no significant differences in OS or CSS among the four groups.

Conclusion

Early-stage MALT-type PPL is indolent in nature. Neither surgery, chemotherapy nor a combination of surgery and chemotherapy can improve OS and CSS, suggesting that “watch and wait” may be a reasonable alternative.

Liver pseudolymphoma (reactive lymphoid hyperplasia): Difficulty in radiological and pathological diagnosis

Pseudolymphoma of the liver (reactive lymphoid hyperplasia) (RLH) is a rare condition. It is usually asymptomatic and detected incidentally on radiological imaging. Imaging features are similar to hepatic adenoma, hepatocellular carcinoma, cholangiocarcinoma, and malignant lymphoma and are not specific for pseudolymphoma of the liver. Percutaneous core biopsy is insufficient to distinguish pseudolymphoma of the liver from low-grade malignant lymphoma and extranodal marginal lymphomas. In this article, we present a case of hepatic RLH of a patient who presented with a skin rash on the leg and was detected incidentally on radiological imaging.

Thoracic positron emission tomography: 18F-fluorodeoxyglucose and beyond

Ongoing technologic and therapeutic advancements in medicine are now testing the limits of conventional anatomic imaging techniques. The ability to image physiology, rather than simply anatomy, is critical in the management of multiple disease processes, especially in oncology. Nuclear medicine has assumed a leading role in detecting, diagnosing, staging and assessing treatment response of various pathologic entities, and appears well positioned to do so into the future. When combined with computed tomography (CT) or magnetic resonance imaging (MRI), positron emission tomography (PET) has become the sine quo non technique of evaluating most solid tumors especially in the thorax. PET/CT serves as a key imaging modality in the initial evaluation of pulmonary nodules, often obviating the need for more invasive testing. PET/CT is essential to staging and restaging in bronchogenic carcinoma and offers key physiologic information with regard to treatment response. A more recent development, PET/MRI, shows promise in several specific lung cancer applications as well. Additional recent advancements in the field have allowed PET to expand beyond imaging with ¹⁸F-flurodeoxyglucose (FDG) alone, now with the ability to specifically image certain types of cell surface receptors. In the thorax this predominantly includes ⁶⁸Ga-DOTATATE which targets the somatostatin receptors abundantly expressed in neuroendocrine tumors, including bronchial carcinoid. This receptor targeted imaging technique permits targeting these tumors with therapeutic analogues such as ¹⁷⁷Lu labeled DOTATATE. Overall, the proper utilization of PET in the thorax has the ability to directly impact and improve patient care.

A case of reactive lymphoid hyperplasia of the liver in a patient with autoimmune hepatitis

Background

Reactive lymphoid hyperplasia (RLH) of the liver is a benign disorder. It is usually observed in the skin, orbit, thyroid, lung, breast, or gastrointestinal tract, but rarely in the liver. Since the first report of RLH of the liver in 1981, only 75 cases have been described in the past literature. Herein, we report a case of RLH of the liver in a patient with autoimmune hepatitis (AIH), which was misdiagnosed as hepatocellular carcinoma (HCC) preoperatively and resected laparoscopically.

Case presentation

A 43-year-old Japanese woman with autoimmune hepatitis was followed up for 5 years. During her medical checkup, a hypoechoic nodule in segment 6 of the liver was detected. The nodule had been gradually increasing in size for 4 years. Abdominal ultrasound (US) revealed a round, hypoechoic nodule, 12 mm in diameter. Contrast-enhanced computed tomography (CT) demonstrated that the nodule was slightly enhanced in the arterial dominant phase, followed by perinodular enhancement in the portal and late phases. A magnetic resonance imaging (MRI) scan showed low signal intensity on the T1-weighted image (T1WI) and slightly high signal intensity on the T2-weighted image (T2WI). The findings of the Gd-EOB-DTPA-enhanced MRI were similar to those of contrast-enhanced CT. Tumor markers were all within the normal range. The preoperative diagnosis was HCC and a laparoscopic right posterior sectionectomy was performed. Pathological examination revealed that the nodular lesion was infiltrated by small lymphocytes and plasma cells, and germinal centers were present. Immunohistochemistry was positive for B cell and T cell markers, indicating polyclonality. The final diagnosis was RLH of the liver.

Conclusions

The pathogenesis of RLH of the liver remains unknown, and a definitive diagnosis based on imaging findings is extremely difficult. If a small, solitary nodule is found in female patients with AIH, the possibility of RLH of the liver should be considered.

A case of hepatic pseudolymphoma in a patient with primary biliary cirrhosis

Hepatic pseudolymphoma is a very rare benign reactive lymphoid hyperplasia associated with autoimmunity and chronic inflammatory liver diseases such as primary biliary cirrhosis and may mimic hepatocellular carcinoma. This diagnosis should be suspected in female with a suspicious single tumor. Close monitoring is needed in view of its premalignant nature.

Reactive lymphoid hyperplasia of the liver: A case report

RATIONALE

Reactive lymphoid hyperplasia (RLH) of the liver is an uncommon benign lesion. It is usually difficult to differentiate from hepatocellular carcinoma (HCC), peripheral-type cholangiocellular carcinoma (CCC), combined HCC-CCC, and liver metastases. On account of its rarity and controversial issues, we report a case report and review the literature to discuss its clinical features, treatments, radiological, and immunohistochemical characteristics.

PATIENT CONCERNS

A 54-year-old woman had a history of primary biliary cirrhosis and chronic cholecystitis. She complained of finding a lesion in the right liver during her last medical check-up by abdominal B type ultrasound. The Contrast-enhanced computed tomography revealed a circular and low-density lesion in the right posterior lobe of the liver, approximately 22.0 × 18.7 mm in size. On magnetic resonance imaging, the lesion showed low-signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Laboratory test results were almost normal.

DIAGNOSIS

After the postoperative pathological and immunohistochemical examination, the patient was finally diagnosed as having RLH.

INTERVENTIONS

The patient received right posterior lobe hepatectomy and cholecystectomy.

OUTCOMES

The patient was discharged 11 days after surgery. No evidence of recurrence was noted 1 year after the surgery.

LESSONS

Although RLH of the liver is rare, it is necessary to be considered in a liver lesion, especially in female patients. This case report may advance the understanding of RLH of the liver and reduce the number of mistakenly diagnosed patients.

Rare Primary Pulmonary Marginal Zone Lymphoma Presenting with Incidental Pulmonary Nodules

Pulmonary malignancies carry a significant morbidity and mortality and are one of the leading causes of cancer-related deaths worldwide. Primary pulmonary lymphoma is a rare malignancy which should be considered in the differential of solitary pulmonary nodule or lung mass especially in a low-risk patient presenting with constitutional symptoms. Here, we describe a case of an elderly male who presented to our clinic with incidental pulmonary nodules and subsequent workup revealed low grade B cell non-Hodgkin's lymphoma consistent with diagnosis of primary pulmonary marginal zone lymphoma.

Achromobacter Infection Is Rare in Japanese Patients with Pulmonary B-cell Lymphoma

Objective Achromobacter xylosoxidans (A. xylosoxidans) has been recently reported to have an association with the development of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma in patients from European countries. However, the prevalence rates for A. xylosoxidans may vary significantly from country to country. To assess this association, the prevalence of A. xylosoxidans was analyzed in Japanese patients with pulmonary B-cell lymphoma. Methods DNA samples were obtained from formalin-fixed, paraffin-embedded sections of pulmonary MALT lymphomas (n=52), diffuse large B-cell lymphomas (DLBCLs, n=18), and benign pulmonary lesions (n=19). All samples were histopathologically reviewed by experienced hematopathologists, and the clonality of all MALT lymphoma cases was confirmed by a polymerase chain reaction (PCR)-based IGH rearrangement clonality assay. They were also tested for the API2-MALT1 fusion transcript. The presence of bacterial DNA was assessed with a nested PCR, and DNA sequencing was performed to confirm the PCR specificity. Results A. xylosoxidans DNA was detected in 1/52 cases of pulmonary MALT lymphoma, 2/18 cases of DLBCL, and 0/19 cases of benign pulmonary lesions. The prevalence of A. xylosoxidans in pulmonary lymphoma was not significantly higher than in benign lesions. Conclusion The present study shows that A. xylosoxidans infection may not be associated with pulmonary B-cell lymphoma in a Japanese case series. Large-scale international studies are needed to clarify the role of A. xylosoxidans in pulmonary lymphoma.

Pulmonary mucosa-associated lymphoid tissue lymphoma revisited

This general review sought to clarify the pathophysiological, diagnostic, prognostic, and therapeutic features of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma.MALT lymphoma is the most common pulmonary B-cell lymphoma, which usually occurs in the context of acquired MALT. The disease is slow-growing with an asymptomatic chronic alveolar opacity visible on radiography. Diagnosis requires tissue samples that should be retrieved using minimally invasive techniques, such as bronchoscopy or computed tomography-guided biopsies. The pathophysiology includes cytogenetic abnormalities and autoimmune diseases, whereas an association with a chronic pulmonary infection is still suspected but not yet demonstrated. Disease prognosis is typically excellent and the current available treatments are discussed in this review, including the decision not to treat, surgery, and single- or double-agent chemotherapy.

Pseudolymphoma (reactive lymphoid hyperplasia) of the liver: A clinical challenge

Reactive lymphoid hyperplasia (RLH), also known as pseudolymphoma or nodular lymphoid lesion of the liver is an extremely rare condition, and only 51 hepatic RLH cases have been described in the literature since the first case was described in 1981. The majority of these cases were asymptomatic and incidentally found through radiological imaging. The precise etiology of hepatic RLH is still unknown, but relative high prevalence of autoimmune disorder in these cases suggests an immune-based liver disorder. Imaging features of hepatic RLH often suggest malignant lesions such as hepatocellular carcinoma and cholangiocarcinoma. In this report, we discuss two cases of hepatic RLH in patients with autoimmune hepatitis. We also present pathologic and magnetic resonance imaging findings, including one case utilizing a hepatocellular contrast agent, Eovist. Definitive diagnosis of hepatic RLH often requires surgical excision.

Primary Pulmonary Lymphomas

Primary lung lymphoma (PLL) is a rare disease that comprises <0.5% of all primary lung tumors. It is defined as lymphoma confined to the lung with or without hilar lymph node involvement at the time of diagnosis or up to 3 months thereafter. Patients with PLL may be asymptomatic or manifest nonspecific clinical symptoms, for example, cough, chest pain, and dyspnea. Some individuals may be immunosupressed or have an autoimmune disorder. Radiologically, PLL can mimic pneumonia, lung carcinoma, or metastasis, and therefore, histologic confirmation is mandatory for definitive diagnosis. Primary lung marginal zone lymphoma of mucosa-associated lymphoid tissue type comprises 70% to 80% of cases. Less common B-cell lymphomas include diffuse large B-cell lymphoma, lymphomatoid granulomatosis (LyG), plasmacytoma, and other small lymphocytic lymphomas. PLLs of T-cell origin, largely represented by anaplastic large cell lymphoma, are extremely rare. LyG is an Epstein-Barr virus (EBV)-driven B-cell lymphoid neoplastic proliferation rich in T cells that produces vasculitis. The disease may present at different stages of progression. Differential diagnosis of PLL varies according to the lymphoma subtype: pulmonary mucosa-associated lymphoid tissue lymphoma should be distinguished from reactive inflammatory conditions, whereas high-grade lymphomas may resemble poorly differentiated lung carcinoma, metastatic disease, and other lymphomas. LyG can resemble inflammatory, infectious, and other lymphoid neoplastic processes. A panel of immunohistochemical markers, flow cytometry, and molecular methods are necessary to confirm the diagnosis in the majority of cases. In this article we review the clinical, radiologic, pathologic, and molecular characteristics of several B-cell and T-cell PLLs with exception of Hodgkin lymphoma and posttransplant lymphoproliferative disorder.

A retrospective international study on primary extranodal marginal zone lymphoma of the lung (BALT lymphoma) on behalf of International Extranodal Lymphoma Study Group (IELSG)

Primary lymphoma of the lung is a rare entity. Clinical features, optimal treatment, role of surgery and outcomes are not well defined, and the follow-up is variable in published data. Clinical data of 205 patients who were confirmed to have bronchus mucosa-associated lymphoid tissue lymphoma from December 1986 to December 2011 in 17 different centres worldwide were evaluated. Fifty-five per cent of the patients were female. The median age at diagnosis was 62 (range 28-88) years. Only 9% had a history of exposure to toxic substances, while about 45% of the patients had a history of smoking. Ten per cent of the patients had autoimmune disease at presentation, and 19% patients had a reported preexisting lung disease. Treatment modalities included surgery alone in 63 patients (30%), radiotherapy in 3 (2%), antibiotics in 1 (1%) and systemic treatment in 128 (62%). Patients receiving a local approach, mainly surgical resection, experienced significantly improved progression-free survival (p = 0.003) versus those receiving a systemic treatment. There were no other significant differences among treatment modalities. The survival data confirm the indolent nature of the disease. Local therapy (surgery or radiotherapy) results in long-term disease-free survival for patients with localized disease. Systemic treatment, including alkylating-containing regimens, can be reserved to patients in relapse after incomplete surgical excision or for patients with advanced disease. Copyright © 2015 John Wiley & Sons, Ltd.

Rituximab monotherapy as a first-line treatment for pulmonary mucosa-associated lymphoid tissue lymphoma

Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is a rare extranodal lymphoma with a 5-year survival rate of 80-95 %. There is no standard treatment strategy for pulmonary MALT lymphoma. In the present study, we performed a retrospective evaluation of systemic rituximab monotherapy (375 mg m(-2) day(-1), 4-8 cycles) as first-line treatment in patients with pulmonary MALT lymphoma. Of the eight patients enrolled, five achieved complete response, one achieved partial response, and two showed stable disease. Median progression-free survival was 66.0 months (range 9.7-87.2 months). Treatment was well tolerated and all patients were alive during the median follow-up period of 64.0 months. Rituximab monotherapy was efficacious in patients with pulmonary MALT lymphoma, demonstrating long-term disease stabilization and symptom reduction. Larger prospective studies are warranted to further assess the efficacy of rituximab monotherapy. In conclusion, rituximab monotherapy may be considered for first-line therapy in patients with pulmonary MALT lymphoma.

[Pulmonary malt lymphoma]

This review will describe the current knowledge in the pathophysiology, diagnosis, prognosis and treatment of pulmonary MALT (Mucosa Associated Lymphoid Tissue) lymphoma. Pulmonary MALT lymphomas are low-grade B cell lymphoma and are the most frequent lymphomas arising from the lung. Tumour cells arise from mucosa associated lymphoid tissue. Unlike other sites, no pathogen has been associated with pulmonary location of MALT lymphoma. However addictive translocations involving the MALT1 gene are frequently evidenced Patients are frequently asymptomatic and present with a chronic alveolar opacity. Diagnosis requires histology that may be retrieved by minimally invasive procedures during bronchial endoscopy or by CT scan guided percutaneous biopsies. Prognosis is good and treatment may vary with abstention, surgery, radiotherapy, immunotherapy or chemotherapy.

Pulmonary manifestations of Sjögren's syndrome

Sjögren's syndrome (SS) is primarily defined by its impact on the oral and ocular system resulting in xerostomia and xerophthalmia. However, SS can also manifest throughout the respiratory system. Subclinical pulmonary involvement is common. Clinically significant involvement can result in a 4-fold increased risk of death. Thus, recognizing the many potential presentations of SS in the lung is critical in caring for patients with SS. Additionally, SS should be included in the differential diagnosis of a number of forms of interstitial lung disease.

Crystal-Storing Histiocytosis Complicating Primary Pulmonary Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue

Crystal-storing histiocytosis is an uncommon form of nonneoplastic histiocytic proliferation that in most patients complicates an underlying lymphoproliferative or plasma cell disorder. Lung is a common site of involvement in patients with localized disease. We present an illustrative example from a 54-year-old woman with an asymptomatic solitary lung nodule. The tumor was characterized by sheets of histiocytes with abundant cytoplasm expanded by distinctive eosinophilic inclusions. Focal necrosis was present. Aggregates of monocytoid lymphocytes and clusters of peribronchiolar plasma cells were overshadowed by the histiocytic infiltrate. Immunohistochemical stains showed CD68 staining in nonneoplastic histiocytes and CD20 staining in monocytoid lymphocytes. In situ hybridization studies showed κ light-chain restriction in plasma cells. These results, combined with the histologic findings, supported the diagnosis of crystal-storing histiocytosis complicating marginal zone lymphoma of mucosa-associated lymphoid tissue. We review the literature pertaining to pulmonary crystal-storing histiocytosis, highlighting the differential diagnosis for this rare phenomenon.

Two tracheal BALT lymphoma patients successfully treated with chemotherapy including rituximab

Bronchus-associated lymphoid tissue (BALT) lymphoma of the trachea, an important differential diagnosis for tracheal tumors, is a rare disease with characteristic bronchoscopic findings. In this study, we reviewed 2 cases of patients who were symptomatic at the time of diagnosis, with tumors in the trachea and left main bronchus, putting them at high risk for asphyxia. Chemotherapies including rituximab were administered, and complete remission was confirmed in both cases. Because tracheal tumors often have a pernicious course, it might be beneficial to initiate a chemotherapeutic treatment regimen instead of adopting the "wait-and-see" approach in patients with symptomatic tracheal BALT lymphoma.

Reactive lymphoid hyperplasia of the liver: a clinicopathological study of 7 cases

Background. Reactive lymphoid hyperplasia (RLH) of the liver is a benign focal liver mass that may mimic a malignant liver tumor. Although rarely encountered in clinical practice, it often poses diagnostic and management dilemmas. Methods. Cases diagnosed as hepatic RLH between January 1996 and June 2011 were investigated in a retrospective study. Clinicopathological features as well as follow-up information of the cases were studied. Results. A total of seven cases of hepatic RLH were investigated, with a median age of 46 years (range: 33–76 years). Hepatic RLH was accompanied by concomitant diseases in some patients. The average size of hepatic lesions of our cases was 45 mm (range: 15–105 mm). All of the cases were not accurately diagnosed until confirmed by pathological findings, and surgical resections were performed for all. Postoperative course was uneventful for all of the patients during followup. Conclusions. RLH of the liver is a rare benign disease with a female predilection of unknown etiology. It is very difficult to correctly diagnose this disease without pathological results. Subtle differences on radiological findings of it may be helpful for differential diagnosis from other diseases. Curative resection of the lesion is suggested for the treatment of this disease.

Spontaneously complete regression of pseudolymphoma of the remnant pancreas after pancreaticoduodenectomy

BACKGROUND

Pancreatic pseudolymphoma is extremely rare.

METHOD

We present multiple pseudolymphomas in the head and body of the pancreas. The hypoechoic lesions observed by endoscopic ultrasound were enhanced in late-phase angio-computed tomography and homogeneously hypointensive in T1-weighted magnetic resonance imaging (MRI). (18)F-fluorodeoxyglucose positron emission tomography showed strong accumulation in the lesions. The lesions were suspected to be non-functioning islet cell carcinoma. The intraoperative pathological diagnosis for the specimen obtained by a pylorus-preserving pancreaticoduodenectomy was non-neoplastic lymphoid cells. The remnant lesion in the pancreatic body was preserved.

RESULTS

Macroscopically, the mass was well-circumscribed gray-white colored lesion. The pathological diagnosis was pancreatic pseudolymphoma. The lesion in the remnant pancreas spontaneously disappeared within one year after the operation.

CONCLUSION

The differential diagnosis of pancreatic pseudolymphoma from malignant tumor is very difficult, however, the image findings demonstrated here may be informative. The spontaneous disappearance of pancreatic pseudolymphoma was firstly observed in the present case.

Forty years literature review of primary lung lymphoma

There are several unresolved issues through out the literature regarding the entity of primary lung lymphoma. Extensive literature review of this uncommon pathology is carried out.

By taking into consideration the reported experience, the author discuss the classification, clinical features, histological differential diagnosis, prognostic criteria, therapeutic management and outcome of primary lung parenchyma lymphocytic infiltrates.

An operative case of hepatic pseudolymphoma difficult to differentiate from primary hepatic marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue

Hepatic pseudolymphoma (HPL) and primary hepatic marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) are rare diseases and the differential diagnosis between these two entities is sometimes difficult. We herein report a 56-year-old Japanese woman who was pointed out to have a space occupying lesion in the left lateral segment of the liver. Hepatitis viral-associated antigen/antibody was negative and liver function tests including lactic dehydrogenase, peripheral blood count, tumor markers and soluble interleukin-2 receptor were all within normal limit. Imaging study using computed tomography and magnetic resonance imaging were not typical for hepatocellular carcinoma, cholangiocarcinoma, or other metastatic cancer. Fluorodeoxyglucose-positron emission tomography examination integrated with computed tomography scanning showed high standardized uptake value in the solitary lesion in the liver. Under a diagnosis of primary liver neoplasm, laparoscopic-assisted lateral segmentectomy was performed. Liver tumor of maximal 1.0 cm in diameter was consisted of aggregation of lymphocytes of predominantly B-cell, containing multiple lymphocyte follicles positive for CD10 and bcl-2, consistent with a diagnosis of HPL rather than MALT lymphoma, although a definitive differentiation was pending. The background liver showed non-alcoholic fatty liver disease/early non-alcoholic steatohepatitis. The patient is currently doing well with no sign of relapse 13 months after the surgery. Since the accurate diagnosis is difficult, laparoscopic approach would provide a reasonable procedure of diagnostic and therapeutic advantage with minimal invasiveness for patients. Considering that the real nature of this entity remains unclear, vigilant follow-up of patient is essential.

Update on nonneoplastic pulmonary lymphoproliferative disorders and related entities

CONTEXT

Recent discoveries have expanded the spectrum of nonneoplastic pulmonary lymphoproliferative disorders and have provided new insights into their pathogenesis and treatment.

OBJECTIVE

To review the thoracic manifestations of immunoglobulin (Ig) G4-related sclerosing disease and summarize current concepts and differential diagnosis of follicular bronchiolitis, lymphocytic interstitial pneumonitis, and nodular lymphoid hyperplasia.

DATA SOURCES

Data sources include recent and old articles, cases from the personal files of the author, and cases borrowed with permission from other authors.

CONCLUSIONS

Additional studies will be needed to further refine and add to observations in this evolving area of pulmonary pathology.

A Practical Approach to the Evaluation of Lymphoid and Plasma Cell Infiltrates in the Lung

Pulmonary biopsy specimens demonstrate varying degrees of infiltration by lymphoid cells and plasma cells, which may raise concern about involvement of a lymphoid or plasma cell neoplasm. Although paraffin section immunohistochemical stains and molecular genotyping studies are capable of assisting in the distinction between reactive and neoplastic infiltrates, it can be difficult to decide what studies to perform. This article describes a practical approach for the evaluation of lymphoid and plasma cell infiltrates in the lung through the identification of several key histologic features.

Pseudolymphoma of the liver associated with primary biliary cirrhosis: a case report and review of literature

We report a case of two pseudolymphomas of the liver in a 63-year-old Japanese woman with primary biliary cirrhosis. One of the lesions was found incidentally during a medical examination, presenting as a 10 mm hypodense nodule that revealed hyperdensity in the early phase and hypodensity in the late phase in computed tomography (CT) after injection of contrast medium. Retrospectively, the 10 mm nodule had first been discovered as a 4 mm nodule during CT 4 years previously. Superparamagnetic iron oxide-enhanced MRI revealed another 4 mm hyperintense nodule in segment 6 in addition to the 10 mm hyperintense nodule in segment 7. CT during arterial portography revealed two hypointense nodules. Findings with other imaging modalities such as ultrasonography, magnetic resonance imaging, and hepatic angiography were consistent with hepatocellular carcinoma. A right posterior segmentectomy was performed, and the lesions were microscopically diagnosed as pseudolymphoma. To the best of our knowledge, only 31 other cases of this disease have ever been reported, with a highly asymmetrical male:female ratio of 1:9.7. Although we could find only one case of transformation of hepatic pseudolymphoma into lymphoma in the liver, the exact nature of development from benign pseudolymphoma to malignant lymphoma is still not fully understood and cases of hepatic lymphoma need to be followed carefully.

Differentiation between malignancy and inflammation in pulmonary ground-glass nodules: The feasibility of integrated (18)F-FDG PET/CT

BACKGROUND

(18)F-FDG PET/CT has been used to differentiate malignant solid lung nodules from benign nodules. We assess the feasibility of integrated (18)F-FDG PET/CT for the differentiation of malignancy from inflammation manifested as ground-glass nodules (GGNs) on chest CT.

METHODS

A total of 68 GGNs in 45 patients (M:F=24:21; mean age, 61) fulfilled the following criteria: (a) nodules composed of >/=50% ground-glass opacity, (b) patients who underwent integrated PET/CT within 1 week following dedicated chest CT, (c) definitive diagnosis determined by pathological specimen or at least 9 months of follow-up, and (d) lesions >/=10mm in diameter. 36 malignant GGNs were pathologically proved as adenocarcinoma (n=20), bronchioloalveolar carcinoma (n=11), low-grade lymphoma (n=3), metastatic mucinous adenocarcinoma (n=1) and unknown low-grade malignancy (n=1). 32 inflammatory GGNs were confirmed as pneumonic infiltration as they had disappeared on follow-up CT and were associated with compatible clinical features (n=26) or as chronic inflammation with fibrosis by VATS biopsy (n=6). Using CT density histogram analysis, 14 were classified as pure GGNs and 54 as part-solid nodules. Integrated PET/CT was evaluated by measuring the maximum standardized uptake value (SUV) at the region of interest located at each lesion. The Mann-Whitney U test was performed to compare the SUV of malignancy and inflammation. The optimal cut-off value of SUV to differentiate malignancy from inflammation was determined using a receiver operating characteristic-based positive test. Sensitivity, specificity, accuracy, and positive predictive values (PPV) and negative predictive values (NPV) were calculated at the level of the optimal cut-off value. SUV showing 100% PPV for inflammatory GGNs was evaluated.

RESULTS

In part-solid nodules, the maximum SUV was significantly higher in inflammation (2.00+/-1.18; range, 0.48-5.60) than in malignancy (1.26+/-0.71; range, 0.32-2.6) (P=0.018). On the other hand, in pure GGNs, the maximum SUV of malignancy (0.64+/-0.19; range, 0.43-0.96) and inflammation (0.74+/-0.28; range, 0.32-1.00) showed no difference (P=0.37). Using the optimal cut-off value of SUV as 1.2 (P=0.01) sensitivity, specificity, accuracy, PPV and NPV in part-solid nodules were 62.1%, 80.0%, 70.4%, 78.3% and 64.5%, respectively. Six part-solid nodules, which showed a maximum SUV of higher than 2.6, were all inflammations.

CONCLUSION

The part-solid nodules with positive FDG-PET could be inflammatory nodules rather than malignant nodules. This is a quite paradoxical result when considering the basic knowledge that malignant pulmonary nodules have higher glucose metabolism.

Clinicopathological features of patients with bronchial-associated lymphoid tissue lymphoma

OBJECTIVE

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type is the most frequent type of non-Hodgkin's lymphoma to primarily involve the lung. Pulmonary MALT lymphoma, also known as bronchial-associated lymphoid tissue (BALT) lymphoma, is a rare disease and the clinicopathological features have yet to be clearly elucidated.

PATIENTS AND METHODS

The present study retrospectively reviewed 13 patients (8 men, 5 women) with BALT lymphoma from 3 institutions between 1989 and 2007 to assess clinicopathological features.

RESULTS

At diagnosis, the median age was 61.6 years (range, 37-80 years), and 11 patients were asymptomatic while 2 had non-specific pulmonary symptoms. Two patients had a history of Sjögren's syndrome. Computed tomography of the chest revealed bilateral disease in 7 patients, lung nodules in 8 patients and air space consolidation with or without air bronchogram in 5 patients. In all cases, disease was localized within the lung at the initial diagnosis. Of the 13 patients, 5 remain untreated, while 8 received various combinations of treatment (surgery alone in 6 patients, surgery plus chemotherapy in 1 patient, and radiotherapy alone in 1 patient). Twelve patients remained alive during the median follow-up of 31.3 months (range, 2-147 months), while 1 patient died from unknown causes.

CONCLUSION

The present study indicates that BALT lymphoma tends to be limited to the lung on the initial diagnosis and responds well to local therapy such as surgery. Prognosis for this lymphoma tends to be indolent.

[Immunophenotyping and gene rearrangement analysis in lymphoid/lymphoproliferative disorders of the lungs]

OBJECTIVE

To determine the usefulness, in routine practice, of using polymerase chain reaction to analyze B and T lymphocyte clonality in pulmonary tissue as a tool for the diagnosis of pulmonary lymphoproliferative disorders.

METHODS

Immunohistochemistry and molecular gene rearrangement analysis were performed in order to assess 8 cases of lymphoid interstitial pneumonia (LIP) and 7 cases of pulmonary lymphoproliferative disorders.

RESULTS

All 8 cases of LIP presented moderate to strong immunostaining for CD3, compared with only 2 cases of lymphoma and 1 case of pseudolymphoma (p = 0.02). Gene rearrangement was detected in 4 of the 8 cases, which changed the diagnosis from LIP to lymphoma, showing the importance of gene rearrangement detection in cases of LIP. In this situation, gene rearrangement using the VH/JH and Vgamma11/Jgamma12 primer pairs was detected in 3 cases and 1 case, respectively, and no gene abnormalities were found using the Dbeta1/Jbeta2 and Vgamma101/Jgamma12 primer pairs in any of the cases. A significant positive association was found between the intensity of CD20 and CD68 expression and gene rearrangement using the VH/JH primer pair. Prior to the gene rearrangement, 4 patients with LIP died quickly, whereas only one patient with LIP died after the gene rearrangement.

CONCLUSIONS

Detection of monoclonal B and T cells by immunophenotyping and polymerase chain reaction had an impact on the diagnosis of pulmonary lymphomas in patients previously diagnosed with LIP. Therefore, immunophenotyping and polymerase chain reaction should be used as 'gold standard' techniques in routine practice.

Fatal outcome in bronchus-associated lymphoid tissue lymphoma

Primary pulmonary lymphoma is rare. The most common histological type is the bronchus-associated lymphoid tissue lymphoma. This type of lymphoma has an indolent course and excellent response to therapy. One-third of all cases are diagnosed incidentally. However, due to the rarity of this disease, little is known about its natural history in terms of dissemination and evolution. Herein, we report the unusual case of a 61-year-old man who refused treatment after being diagnosed with bronchus-associated lymphoid tissue lymphoma and died 2 years later from massive lung infiltration without dissemination to other organs.

Bronchus-associated lymphoid tissue lymphomas: an update of a rare extranodal maltoma

Mucosa-associated lymphoid tissue (MALT) lymphomas were first described by Isaacson and Wright in 1983 in a small series of patients with low-grade B-cell gastrointestinal lymphomas. Although MALT lymphomas occur most frequently in the stomach, they have also been described in various non-gastrointestinal sites, such as the salivary gland, conjunctiva, thyroid, orbit, lung, breast, kidney, skin, liver, uterus, and prostate. The risk of a diagnostic dilemma is reduced by the favorable prognosis of this low-grade lymphoma and its tendency to remain localized to the primary site for a long time. On therapeutic grounds, in contrast to nodal lymphomas, low-grade MALT lymphomas also respond favorably to local treatments, such as surgery and/or local radiation therapy. The outcome and prognosis of low-grade MALT lymphomas are more favorable than those for other extranodal lymphomas. The purpose of this review is to point out the state of the art regarding bronchus-associated lymphoid tissues lymphomas in terms of etiology, pathogenesis, clinics, and therapeutics, including our single-center experience of 23 cases.

Pulmonary nodular lymphoid hyperplasia associated with Sjögren's syndrome

Pulmonary nodular lymphoid hyperplasia (NLH) is a term first suggested by Kradin and Mark to describe one or more pulmonary nodules or localized lung infiltrates consisting of reactive lymphoid proliferation. To date, there have been only a few cases of pulmonary NLH reported associated with autoimmune disorders. There is no case of NLH associated with Sjögren's syndrome from Korea in the medical literature. A 56-year-old woman was referred to our hospital with cough productive of sputum and chest tightness. The Computed tomography scans of the chest revealed multiple and well-defined peribronchiolar nodular opacities. A video assisted thoracoscopic surgery (VATS) biopsy was performed and the nodular opacity in the lung parenchyma was pathologically confirmed as NLH. Through meticulous review of patient's record, we found that she had been suffering from dry eye and dry mouth. The symptoms suggested Sjögren's syndrome, which was confirmed by specific laboratory tests including the Schirmer test, anti-nuclear antibody and anti-Ro/La antibody. The patient is followed regularly and has no further progression of symptoms.

[Malt lung lymphoma]

MALT lung lymphoma is a low-grade primarily B-cell lymphoma. Most cases develop in a pain free patient presenting a chronic alveolar opacity. In this review, we describe the clinical radiological and pathological features as well as the diagnostic approach to this pathological entity. Prognosis is excellent. Therapeutic options are discussed.

Pulmonary lymphoma of mucosa-associated lymphoid tissue type followed as a long-standing indeterminate lesion in immunoglobulin M-type paraproteinemia

An 82-year-old woman with monoclonal immunoglobulin (Ig) M-type paraproteinemia had a large opacity in the right lung field. The abnormal shadow on roentgenogram had persisted for more than 6 years since the initial diagnosis of paraproteinemia, which had been diagnosed as Waldenström's macroglobulinemia (WM). Computed tomography revealed the lesion as a pulmonary tumor which was finally diagnosed as a marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) after surgical removal. MALT lymphoma constitutes the majority of primary pulmonary lymphomas and is often associated with monoclonal IgM-type paraproteinemia as well as WM, a distinctive lymphoproliferative disorder. Pulmonary MALT lymphoma should frequently be suspected in case of an indeterminate pulmonary tumor with IgM-type paraproteinemia.

Serous effusions in malignant lymphomas: A review

Serous effusions are a common complication of lymphomas. Although the frequency of pleural effusion is 20-30% in non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), the involvement of peritoneal and pericardial cavities is uncommon. Among lymphoma subtypes, T-cell neoplasms, especially the lymphoblastic lymphomas, more frequently involve the serous fluids. The thoracic duct obstruction and impaired lymphatic drainage appear to be the primary mechanism for pathogenesis of pleural effusion in HD and direct pleural infiltration is the predominant cause in NHL. There is wide variation in rate of positive cytologic findings of NHL in pleural effusion (22.2-94.1%). Cytologic features of specific lymphoma subtypes such as lymphoblastic lymphoma, follicular center cell lymphoma, including Burkitt-type lymphoma, marginal zone lymphoma, MALT lymphoma, and anaplastic large-cell lymphoma, etc., have been described in the literature. The differential diagnostic problems of lymphomas in serous effusions include reactive lymphocytoses, early involvement by lymphomatous process, small round-cell tumors (SRCT), and presence of look-alike of Reed-Sternberg cells. To overcome these difficulties, various ancillary studies, including immunocytochemistry (ICC), morphometry, flow cytometry (FCM), and cytogenetics/molecular genetics (PCR, in-situ hybridization, and Southern blotting), have been performed on effusion specimens. ICC not only distinguishes lymphomas from reactive lymphocytoses and SRCTs, it significantly modifies the morphologic diagnosis to achieve a better classification of lymphomas. Combined morphology and immunophenotyping by FCM, has a sensitivity as well as specificity of 100%. Morphometry also distinguishes reactive lymphocytoses from malignant lymphoma with a high degree of sensitivity (>85%) and specificity (>95%). Limitations of individual ancillary techniques can be overcome by using multiple parameters. Although lymphomas rarely present as serous effusions without the involvement of other thoracic and extrathoracic sites, a small group of lymphomas called primary effusion lymphomas (PEL) exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. This body cavity based lymphoma (BCBL) is a distinct clinicopathologic entity and is found predominantly in AIDS patients with preexisting Kaposi sarcoma. In the absence of obstructive or infiltrative tumor mass, its pathogenesis has been attributed to stimulation by vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF), leading to vascular leakage. Cytomorphologically, PEL is usually a large-cell lymphoma, which appears to bridge features of large-cell immunoblastic and anaplastic large-cell lymphoma (ALCL). Most of these cases comprise a unique subgroup of B-cell lymphoma, with features of both high-grade anaplastic and B-immunoblastic lymphoma, but T-cell and/or natural killer cell immunophenotypes are described. Its association with various viral DNAs has been studied in detail by molecular techniques. Pleural effusion due to lymphomas, either primary or otherwise, is considered as one of the factors adversely influencing overall survival. The presence of pleural effusion at the time of presentation is not only associated with extremely poor outcome of lymphomas, it is also a predictor of disease relapse after chemotherapy and decreased survival. When the patients of lymphomatous pleural effusions with and without mediastinal mass present in respiratory distress, thoracocentesis is the initial diagnostic and therapeutic choice in these patients. In such situations, cytology along with ancillary studies not only gives a quick diagnosis of lymphoma, but also offers prognostically significant information such as classification of lymphomas, its grade and immunophenotype, and presence/absence of viral DNAs and tumor lysis syndrome.

Pulmonary lymphoma of the mucosa-associated lymphoid tissue type: report of a case with cytological, histological, immunophenotypical correlation, and review of the literature

A 59-year-old woman presented to The University of South Alabama, Mobile, Ala, with the complaint of shortness of breath. A chest radiograph showed bilateral nodules and interstitial infiltrates. The diagnosis of lymphoma was suggested on bronchial brush smears. Biopsy revealed a multifocal centrocyte-like lymphoid infiltrate involving the bronchial walls with lymphoepithelial lesions. The lymphocytes were positive for CD19, CD20, and CD22. A diagnosis of pulmonary lymphoma of the mucosa-associated lymphoid tissue type was established and the patient responded to chemotherapy treatment. Over the following 5 years, she suffered at least 2 recurrences involving the lung and breast for which she received additional treatment.

Malignant and benign lymphoid lesions of the lung

Lymphoid lesions of the lung produce a complex of problems for the practicing pathologist. Although these lesions are eventually referred to hematopathologists, it is still the general surgical pathologist who first encounters them and confronts the problem of formulating an initial diagnosis. Over the last 20 years there has been a revolution in our knowledge of the classification and natural history of the pulmonary lesions, a plethora of information which warrants a thorough review. The purpose of this discussion is to report the clinical features and courses, pathologic features and, when known, etiologies or pathogenesis of the major "primary" pulmonary lymphoid lesions and present a brief approach to differential diagnosis. I will divide the lesions into malignant and benign, discussing each in turn.

Bronchial-associated lymphoid tissue lymphoma: a clinical study of a rare disease

Bronchial-associated lymphoid tissue (BALT) lymphoma is a distinct subgroup of low-grade B-cell extranodal non-Hodgkin's lymphoma, classified as marginal-zone lymphoma. This study was performed in order to assess the natural history of this rare entity. We evaluated retrospectively the clinical data of 22 patients with biopsy-proven BALT lymphoma at two tertiary-care institutions from 1996 to 2002. Immunophenotyping was done to confirm the abnormal populations of B-lymphoid cells in all cases, and clonality was determined by flow cytometry or molecular studies. There were 11 men and 11 women in the sample, median age 61 years (range 21-80 years); nine were asymptomatic at diagnosis. All 13 symptomatic patients had non-specific pulmonary complaints. On computed tomographic examination of the chest, 11 patients had bilateral disease, 12 had lung nodules, and 10 had a mass or air-space consolidation. In all but one case the disease was localised to the lung at diagnosis and none had peripheral blood or bone marrow involvement. Out of 22 patients, 20 received treatment in various combinations, 12 had chemotherapy and/or rituximab, six had surgery, and two received radiation therapy as primary treatment. A complete response (CR) was achieved in nine patients and a partial response was obtained in 10 patients. Seven of 10 patients who had unilateral disease achieved a CR. The estimated progression-free survival was 53 months. All patients were alive during the median follow-up period of 36 months (range 12-76 months). It appears that BALT lymphoma tends to be localised to lung at the time of diagnosis, responds well to local or systemic therapy, and has a favourable prognosis.

Low-grade B-cell bronchial associated lymphoid tissue (BALT) lymphoma

Low-grade B-cell bronchial associated lymphoid tissue (BALT) lymphoma is a distinct subgroup of non-Hodgkin's lymphoma. Chronic antigen stimulation, triggered by autoimmune process or persistent infection may precede the development of BALT lymphoma. The lymphoma cells originate from the marginal zone and by invading the bronchial epithelial tissue, give rise to the lymphoepithelial lesion. BALT lymphoma shares the morphologic, immunophenotypic, and cytogenetic characteristics of other mucosa associated lymphoid tissue lymphomas. A majority of the patients are asymptomatic and pulmonary lesions are incidentally discovered on a routine chest radiograph. However, the clinical and radiographic features of BALT lymphoma are nonspecific. The disease is often localized at the time of diagnosis and responds favorably to local treatment, but the optimal management is not clearly defined. Overall, BALT lymphoma has a favorable prognosis and is associated with long-term survival.

Unsuspected primary pulmonary malignant lymphoma

A 70-year-old man referred for treatment of a left lower lung tumor was shown in chest computed tomography to have a homogeneous round tumor 45 mm in diameter with an enhanced thin wall in the lower lobe of the left lung. No specific finding was seen in material obtained by transbronchial and computed tomography (CT)-guided lung tissue biopsy, so the presumptive diagnosis was a lung abscess. Despite antibiotics administered for 2 weeks, radiography showed the tumor had grown, necessitating left lower lobectomy. The permanent section was diagnosed as diffuse large B-cell lymphoma. Because CT findings for the tumor suggested a lung abscess and the central part of the tumor consisted of fibrotic and necrotic tissue, we had difficulty establishing a final diagnosis. The literature showed primary pulmonary lymphomas yielded a variety of findings radiographically, making surgery paramount for ascertaining a final diagnosis.

Pseudolymphoma of the Lung: Benign or Malignant?

Pseudolymphoma of the lung has been considered benign, premalignant, or frankly malignant. A case that responded to simple surgical resection is described. The patient remained well during a follow-up of more than 10 years.