Pulmonary pseudoneoplasms

Huge mesenteric inflammatory myofibroblastic tumor as a rare cause of intussusception with recurrence after 10 months: Case report and literature review

INTRODUCTION AND IMPORTANCE

Inflammatory myofibroblastic tumor (IMT) is an infrequent, generally non-cancerous mesenchymal growth. IMT can affect individuals across various age groups, with a higher prevalence in children and adolescents. While it can emerge in any bodily region, it has a tendency to develop more often in the lungs and mesentery. IMT occurrence in the small bowel is exceptionally uncommon. It's a rare cause of intussusception and has unpredictable recurrence rate.

CASE PRESENTATION

This report highlights a unique clinical presentation involving a mesenteric IMT, which presented as small intestine intussusception in a 2-year-old child. Additionally, the patient was found to have an asymptomatic mass in the right upper quadrant, later identified as a recurrent IMT 10 months after surgical intervention for intussusception caused by the same tumor.

CLINICAL DISCUSSION

IMTs originate from mesenchymal tissues and encompass a blend of fibroinflammatory conditions. They exhibit a diverse combination of inflammatory and spindle cells. Diagnosing IMTs prior to surgery is intricate, as they can mimic malignant growths. Histopathology following surgery is usually needed for confirmation. Complete removal with a clear margin is the favored treatment approach.

CONCLUSION

Intestinal IMT is an infrequent and often overlooked condition, but it should be taken into account when diagnosing small bowel intussusception. The best chance of preventing recurrence in cases of intestinal IMT is through complete surgical removal with a negative margin. Nonetheless, the most effective approach for managing local recurrence and metastasis is still uncertain and necessitates ongoing long-term observation.

Nodular Lymphoid Hyperplasia as Incidental Finding of Suspect Pulmonary Mass

Nodular lymphoid hyperplasia of the lung is a rare disease of polyclonal lymphoid proliferation. The incidental finding of a solid nodular lesion with irregular margins adjacent to the visceral pleura in the reported case was highly suggestive of malignancy. The present report underscores the typical immunohistochemical findings and the benign course of nodular lymphoid hyperplasia. The current knowledge about disease aetiology and the value of different diagnostic tools to distinguish nodular lymphoid hyperplasia from other pulmonary lymphoid lesions are summarized by a review of the literature. Surgical resection is not only diagnostic but also curative with no evidence so far that NLH can regress without operation. The present case shows the spontaneous regression of NLH after CT-guided biopsy indicating that an alternative, less invasive diagnostic approach has curative potential.

The diagnostic challenge of adenocarcinoma in pulmonary nodular lymphoid hyperplasia

Pulmonary nodular lymphoid hyperplasia is a rare, nonneoplastic lymphoproliferative disorder mostly manifesting as one or more nodules or localized lung infiltrates. The lesion comprises reactive germinal centers with well-preserved mantle zones and sheets of interfollicular mature plasma cells, lymphocytes, histiocytes, and neutrophils. The radiological finding is not specific, and the diagnosis of pulmonary nodular lymphoid hyperplasia relies generally on pathohistological and immunohistochemical analyses. The most important differential diagnoses are extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue and immunoglobulin G4–related sclerosing disease. Nonetheless, we present a case of pulmonary nodular lymphoid hyperplasia in a 69-year-old woman with the diagnostic challenge of cytological atypia in alveolar spaces inside the lymphoid tissue, coexisting with the diagnosis of adenocarcinoma of the lepidic pattern. Therefore, this case highlights the importance of identifying these rare benign and reactive lymphoproliferative diseases given the risk of developing not only lymphoma but also carcinoma.

Non-neoplastic inflammatory pseudotumor of the lung after immunotherapy for melanoma: A diagnostic pitfall on fine needle aspiration biopsy of lung

Nivolumab is commonly used as monotherapy or in combination therapy for management of locally advanced or metastatic melanoma; however, it is also associated with immunotherapy-related adverse events concerning for disease progression or tumor flare reaction. This report presents a case of a non-neoplastic pseudotumor of the lung initially mistaken for malignancy that occurred in a patient receiving adjuvant nivolumab therapy following complete resection of stage IIIB melanoma. The diagnosis was made by lung biopsy and confirmed by a wedge resection, with findings consistent with organizing pneumonia type of pulmonary inflammatory pseudotumor rather than malignancy.

Abdominal elastotic lesions. A clinicopathologic study of 23 cases

Abdominal elastotic deposits are uncommon lesions that often presents as polyps. They show three histological patterns: fibroelastosis, angioelastosis, and elastofibroma. We describe 23 cases including rare locations, such as mesentery, greater omentum, hernia sac, spleen, peripancreatic fat, and hypodermal fat. The age of the patients ranged from 49 to 93 years (mean, 76.8 years). Most lesions were discovered incidentally in the microscopic study. The most frequent locations were peritoneal subserosa (43.5%) and mesentery/mesocolon/greater omentum (39.1%). The most common pattern was fibroelastosis (69.6%) followed by angioelastosis (26.1%). We observed one case of omental elastofibroma. A review of the 14 abdominal elastofibromas described including our case revealed that the age of the patients ranged from 45 to 88 years (mean, 68.5 years). Female predominance is striking (M:F, 1:12). The most common site was the stomach (50%). The greater omentum (14.3%), small intestine (7.1%), and pancreas (7.1%) are very rare sites for this lesion. Only one case before ours has been published in the greater omentum. The size of the lesions ranged from 0.7 cm to 8 cm (mean 3.2 cm). In 36.4% of the cases located in the digestive tract, the mucosa did not show alterations. Ulcerations (36.4%) or polypoid excrescences (18.2%) were mostly observed. Six (42.9%) cases were asymptomatic and six (42.9%) cases simulated a neoplasm. Two cases were associated with elastofibromas in other locations. Differential diagnosis includes amyloidoma, elastofibrolipoma, mesenteric elastic vascular sclerosis in neuroendocrine tumors, diverticular disease elastosis, pseudoxanthoma elasticum, pulse granuloma, and digestive lesions in patients treated with D-Penicillamine.

Mesenteric inflammatory myofibroblastic tumor as a rare cause of small intestinal intussusception

Inflammatory myofibroblastic tumor (IMT) is an uncommon, usually benign, mesenchymal tumor. IMT affects people of all ages, but it more commonly occurs in children and adolescents. Also, it has the potential to arise in any part of the body, though, it frequently develops in the lungs and mesentery. In this report, we discuss a rare clinical manifestation of mesenteric IMT presented as intussusception of the small intestine in a 7-year-old child.

Syphilitic Pulmonary Inflammatory Pseudotumor: A Diagnostic Challenge

A 46-year-old man presented with nonproductive cough and lower limb swelling. Chest radiograph showed a left lower lobe lung mass and multiple subpleural nodules. Other investigations revealed that he had nephrotic syndrome. Core biopsies of the left lower lobe lung mass showed features of inflammatory pseudotumor with endarteritis obliterans and a lymphoplasmacytic infiltrate. Immunohistochemical stain for Treponema pallidum was positive. Resolution of the lung mass and nephrotic syndrome was achieved after treatment with intramuscular benzathine benzylpenicillin. The differential diagnosis of pulmonary inflammatory pseudotumor, manifestations of pulmonary syphilis, and a literature review of secondary syphilis of the lung are discussed.

Sclerosing Mediastinitis Causing Unilateral Pulmonary Edema Due to Left Atrial and Pulmonary Venous Compression. A Case Report and Literature Review

Sclerosing mediastinitis (SM), previously named chronic fibrosing mediastinitis, is an inflammatory process that in its end-stage results to sclerosis around the mediastinal structures. SM is quite rare and has been correlated with inflammatory and autoimmune diseases, as well as malignancy. SM may either present in a mild form, with minor symptoms and a benign course or in a more aggressive form with severe pulmonary hypertension and subsequent higher morbidity and mortality. The diagnosis of SM may be difficult and quite challenging, as symptoms depend on the mediastinal structure that is mainly involved; quite often the superior vena cava. However, practically any mediastinal structure may be involved by the fibrotic process, such as the central airways, as well as the pulmonary arteries and veins, leading to obstruction or total occlusion. The latter may be impossible to undergo proper surgical excision of the lesion, and is considered to be a real challenge to the surgeon. We herein report a case of SM that presented with arterial and venous compression. The imaging appearance was that of unilateral pulmonary edema, associated with lung collapse. The case is supplemented by a non-systematic review of the relevant literature.

Pulmonary Nodular Lymphoid Hyperplasia

Pulmonary nodular lymphoid hyperplasia is an uncommon reactive lymphoproliferative disorder that presents as an asymptomatic lung mass. The histopathologic diagnosis of pulmonary nodular lymphoid hyperplasia may be challenging because of its morphologic overlap with other diseases, such as extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue and immunoglobulin G4-related sclerosing disease. Despite the similarities, there are distinctive morphologic and phenotypic features that allow for the correct diagnosis in the majority of cases. This review aims to discuss the clinicopathologic features of pulmonary nodular lymphoid hyperplasia and contrast them with its histopathologic mimickers.

Reprint of: Pathologic manifestations of Immunoglobulin(Ig)G4-related lung disease

Immunoglobulin(Ig)G4-related disease (IgG4-RD) is a fibroinflammatory condition that can affect virtually any organ and usually presents as tumefactive lesions involving multiple sites. Characteristic histopathology of IgG4-RD consists of dense lymphoplasmacytic infiltrate, fibrosis (often in storiform pattern), and obliterative phlebitis, accompanied by tissue infiltration of IgG4-positive plasma cells with or without elevation of serum IgG4 level. Despite a general similarity in the morphologic manifestations of IgG4-RD, site-specific unique morphologic features have been described in some organs including the lung. Compared with other sites, pulmonary involvement by IgG4-RD has been recognized more recently, and lung biopsy interpretation for this condition is often challenging, as both a relative paucity of pathognomonic features and a plethora of overlapping findings with other fibroinflammatory processes of the lung. This review is focused on the morphologic spectrum of IgG4-related lung disease documented in the current literature and on the pertinent issues in the differential diagnoses with other conditions encountered in the lung.

Pulmonary Nodular Lymphoid Hyperplasia with Mass-Formation: Clinicopathologic Characteristics of Nine Cases and Review of the Literature

Background

Pulmonary nodular lymphoid hyperplasia (PNLH) is a non-neoplastic pulmonary lymphoid disorder that can be mistaken for malignancy on radiography. Herein, we present nine cases of PNLH, emphasizing clinicoradiological findings and histological features.

Methods

We analyzed radiological and clinicopathological features from the electronic medical records of nine patients (eight females and one male) diagnosed with PNLH. IgG and IgG4 immunohistochemical staining was performed in three patients.

Results

Two of the nine patients had experienced tuberculosis 40 and 30 years prior, respectively. Interestingly, none were current smokers, although two were ex-smokers. Three patients complaining of persistent cough underwent computed tomography of the chest. PNLH was incidentally discovered in five patients during examination for other reasons. The remaining patient was diagnosed with the disease following treatment for pneumonia. Imaging studies revealed consolidation or a mass-like lesion in eight patients. First impressions included invasive adenocarcinoma and mucosal-associated lymphoid tissue‒type lymphoma. Aspergillosis was suspected in the remaining patient based on radiological images. Resection was performed in all patients. Microscopically, the lesions consisted of nodular proliferation of reactive germinal centers accompanied by infiltration of neutrophils and macrophages in various degrees and surrounding fibrosis. Ultimately, all nine patients were diagnosed with PNLH and showed no evidence of recurrence on follow-up.

Conclusions

PNLH is an uncommon but distinct entity with a benign nature, and understanding the radiological and clinicopathological characteristics of PNLH is important.

Possible relationship between fibrosis of IgG4-related thymitis and the profibrotic cytokines, transforming growth factor beta 1, interleukin 1 beta and interferon gamma: a case report

BACKGROUND

IgG4-related disease often forms a mass and the affected lesion is clinically removed because the mass cannot be differentiated from a neoplasm. Affected lesions commonly occur in the pancreas, hepatobiliary tract, kidney, and retroperitoneum. However, the lesion rarely occurs in the thymus. A histological worldwide consensus of IgG4-related disease proposed that pathological diagnosis of IgG4-related disease should meet more than two of three major features: 1) dense lymphoplasmacytic infiltration with greater than 40% IgG4+/IgG+ plasma cells, 2) storiform fibrosis; and 3) obliterative phlebitis. Currently, fibrosis of IgG4-related disease is thought to be induced by profibrotic cytokines such as transforming growth factor beta 1 (TGFB1), interleukin 1 beta (IL1B) and interferon gamma (IFNG), which are secreted by regulatory T cells (Tregs) and CD4-positive cytotoxic T cells. However, it is unclear whether profibrotic cytokines are associated with the fibrosis seen in IgG4-related thymitis. Here we examined whether cytokines in the mass were increased compared with those in the surrounding thymus, and whether Tregs were present in the mass, using reverse transcription absolute quantitative polymerase chain reaction (RT-ab-qPCR) and immunohistochemistry.

CASE PRESENTATION

A 70-year-old Japanese man contracted IgG4-letated thymitis. Histological and immunohistochemical analyses demonstrated his mass had massive fibrosis with a focally storiform pattern and lymphoplasmacytic infiltration with 40% IgG4+/IgG+ plasma cells, but not obliterative phlebitis. The mass was surrounded by atrophic thymus. We diagnosed the mass as IgG4-related thymitis. Immunohistochemically, Tregs were scattered throughout the mass. RT-ab-qPCR showed that messenger RNA expressions of TGFB1, IL1B and IFNG in the mass were 270-, 158- and 5.5- fold higher than in the surrounding thymus. His serum IgG4 level after surgery was within the normal range (83.4 mg/dl soon after surgery, 89.3 mg/dl 2 weeks after surgery).

CONCLUSIONS

Our results suggested the profibrotic cytokines TGFB1, IL1B and IFNG induce fibrosis and that Tregs might produce some of these cytokines in IgG4-related thymitis as well as in the other affected lesions of IgG4-related disease.

Sclerosing Mediastinitis Presenting as Complete Heart Block

Sclerosing Mediastinitis (SM) is a rare condition which is characterized by the presence of dense fibrosis which infiltrates and encroaches upon various structures in the mediastinal cavity. Depending on the extent and the predominant organ of involvement, the patient presents with symptomatology of dysphagia, superior vena cava compression syndrome or dyspnoea. However, the involvement of the heart is rarely seen. Aetiologies of SM are several, with infections being the most common. We discuss a case of SM involving the oesophagus, descending aorta, hilum of lungs and the heart secondary to mucormycosis in an immunocompetent male.

Extranodal Marginal Zone Lymphoma of the Lung: Evolution from an Underlying Reactive Lymphoproliferative Disorder

Extranodal Marginal Zone Lymphoma (ENMZL) of Mucosa-Associated Lymphoid Tissue (MALT) is a problematic and sometimes controversial diagnosis. While commonly seen in the stomach in the setting of chronic Helicobacter pylori infection, other extranodal sites, such as the lung, may also present with disease. ENMZL is clinically and morphologically heterogeneous; however, regardless of presentation, the etiology lies in the accumulation of lymphoid tissue in non-traditional sites. This phenomenon is typically secondary to an underlying inflammatory stimulus such as chronic infection or autoimmune states. The current case report details the clinical history of a patient with Sjögren syndrome over a four year period who eventually developed ENMZL. The patient initially presented with an atypical, but polyclonal, lymphoproliferative process diagnosed as lymphocytic interstitial pneumonia. Over time, the patient showed evolution to a monoclonal process with associated radiologic progression of disease. This evolution manifested as a dense lymphoid infiltrate with prominent plasmacytic differentiation and the development of a lung mass radiologically. This case contributes to the growing body of knowledge that suggests ENMZL lies along a biological spectrum of lymphoproliferative disorders whereby a benign, reactive process may eventually undergo malignant transformation. This evolution likely represents the acquisition of genetic abnormalities that allow autonomous proliferation in the absence of the initial immune stimulus. In practice, determining when this event occurs and, thus, distinguishing between reactive and neoplastic disorders within this spectrum may be difficult as no single clinicopathologic feature may be present to establish the diagnosis. This case further illustrates the importance of correlating the clinical, radiologic and pathologic data to evaluate patients with atypical pulmonary lymphoproliferative disorders and to allow the optimal management of their disease.

Inflammatory pseudotumor of the pleura

Inflammatory pseudotumors are rare solid, non-neoplastic masses that can mimic pulmonary malignancy. It occurs most commonly in children and young adults and is usually found incidentally. There are many reports of the existence of this tumor in various organs in the human body. The occurrence of this tumor exclusively in the pleura has not been described before. We present a case of inflammatory pseudotumor of the pleura and its successful management.

A 60-year-old woman with PET scan-avid lung nodules and a history of a ruptured silicone breast implant

A 60-year-old woman was referred to the pulmonary clinic for evaluation of lung nodules. Her medical history was notable for hypothyroidism, anxiety, and a ruptured breast implant for which incomplete surgical resection and evacuation had been performed 10 years previously. She was a lifelong nonsmoker and worked as a gym instructor. The patient denied occupational exposures and had not traveled recently. Medications included levothyroxine and alprazolam. Except for a 1-month history of occasional dry cough, the review of systems was negative. The patient's physician queried whether the previously ruptured silicone breast implant may have played a role in the genesis of the nodules and referred the patient to our institution for further management. The lack of systemic symptoms relative to the degree of lung involvement provided an early diagnostic clue.

Encapsulating peritoneal sclerosis--correlation of radiological findings at CT with underlying pathogenesis

Encapsulating peritoneal sclerosis (EPS) is a rare entity most commonly associated with peritoneal dialysis (PD). Several imaging features at computed tomography (CT) are common to many diseases; however, appreciation of the features unique to this condition interpreted with the appropriate clinical findings is crucial to diagnosis.

Diagnostic and therapeutic challenges of a large pleural inflammatory myofibroblastic tumor

We report a 48-year-old woman with a pleural pseudoneoplasm requiring different diagnostic and therapeutic strategies. After initial presentation with increasing dyspnoea, temperature, dry cough, and interscapular pain diagnostic processing showed a large mediastinal mass with marked pleural effusion and high metabolic activity in the 18F-FDG-PET/CT. Extensive CT-guided biopsy of the tumor reaching from the visceral pleura into the right upper lobe revealed no malignancy, but a marked inflammatory tissue reaction containing foam cells. Initial empiric antibiotic therapy was temporarily successful. However, in the further course the mass relapsed and was resistant to antibiotics and a corticosteroid trial. With the working hypothesis of an inflammatory myofibroblastic tumor the patient underwent surgical tumor resection, finally confirming the suspected diagnosis. Due to residual disease intravenous immunoglobulins were administered leading to sustained response. This case with a pleural localisation of a large inflammatory pseudotumor with responsiveness to immunomodulation after incomplete resection extends the reported spectrum of thoracopulmonary manifestations of this rare entity.

Pathologic manifestations of Immunoglobulin(Ig)G4-related lung disease

Immunoglobulin(Ig)G4-related disease (IgG4-RD) is a fibroinflammatory condition that can affect virtually any organ and usually presents as tumefactive lesions involving multiple sites. Characteristic histopathology of IgG4-RD consists of dense lymphoplasmacytic infiltrate, fibrosis (often in storiform pattern), and obliterative phlebitis, accompanied by tissue infiltration of IgG4-positive plasma cells with or without elevation of serum IgG4 level. Despite a general similarity in the morphologic manifestations of IgG4-RD, site-specific unique morphologic features have been described in some organs including the lung. Compared with other sites, pulmonary involvement by IgG4-RD has been recognized more recently, and lung biopsy interpretation for this condition is often challenging, as both a relative paucity of pathognomonic features and a plethora of overlapping findings with other fibroinflammatory processes of the lung. This review is focused on the morphologic spectrum of IgG4-related lung disease documented in the current literature and on the pertinent issues in the differential diagnoses with other conditions encountered in the lung.

Pulmonary histoplasmosis producing a spindle cell "pseudotumor"

Pulmonary spindle cell proliferations have been reported in association with a limited group of infectious agents. These lesions are rare and identified most often in the setting of immunosuppression. Because their appearance can simulate a spindle cell neoplasm, they are diagnostically treacherous, sometimes delaying antimicrobial therapy or resulting in unnecessary surgery. We report a case of a spindle pseudotumor of the lung resulting from Histoplasma capsulatum infection, a previously unreported cause of a spindle cell lesion in the lung. The patient was a 67-year-old woman in whom positron emission tomography-positive nodules developed in the left lung and left mediastinum. The patient had undergone renal transplantation and was receiving immunosuppressive therapy with mycophenolate, tacrolimus, and low-dose prednisone. Infection with H capsulatum was confirmed by culture of pleural effusion fluid, DNA probe analysis of the pleural fluid culture isolate, urinary Histoplasma antigen detection, and Grocott methenamine silver stains of tissue sections. To our knowledge, this is the first case of a spindle cell "pseudotumor" of the lung resulting from histoplasmosis. It highlights the importance of performing special stains for organisms when evaluating pulmonary spindle cell lesions in an immunocompromised host.

Round atelectasis in sarcoidosis

Round atelectasis is a benign inflammatory condition most frequently observed in patients with asbestos exposure but it can also result from a variety of chronic pleural diseases like infection. It has not previously been described in sarcoidosis. We report the occurrence of round atelectasis in four previously diagnosed sarcoidosis patients who were under follow up at our outpatient clinic. Three patients had symptoms consisting of thoracic pain, dry cough and sensation of fullness at the posterior thorax, respectively. Chest roentgenogram showed subpleural or pleural based opacity with diameters ranging from 2 to 3 cm in each of the patients. Chest computerized tomography (CT) revealed features of round atelectasis. Fiberoptic bronchoscopy with transbronchial lung biopsy was performed. Diagnosis was confirmed by the histopathologic examination of the biopsy samples. The mechanical influence of a prior pleural effusion due to sarcoidosis may be the predominant mechanism underlying the onset of round atelectasis in these patients. Clinicians should bear in mind the possibility of sarcoidosis as an etiologic factor for round atelectasis.