GABAA receptor and anti-titin antibody encephalitis in a patient with thymoma.

Autoimmune encephalitis (AE) associated to antibodies against GABA A R is a rare form of encephalitis. On the other hand, thymoma has been linked to antibodies against both muscular and neuronal epitopes, even if concurrent positivity for more than one antibody is exceptional, and their contribution to the clinical course and treatment decision is unclear. We report a case of a 73-year-old male with AE associated with thymoma secreting both anti-GABAaR and anti-titin antibodies. Clinical presentation included status epilepticus, behavioural changes and cognitive decline. While the status was stopped with lacosamide, AE treatment included first- and second-line immunomodulation, in addition to thymoma's removal. Nonetheless, the patient experienced a worsening in cognitive and behavioural status.

Mediastinal Rosai-Dorfman Disease With Widespread Lesions: When Surgical Biopsy Is Needed.

Rosai-Dorfman disease (RDD) is a rare benign disorder of the histiocytes, affecting lymph nodes in its classic form. Extranodal RDD is considered the uncommon subtype and potentially impairs all tissues and intrathoracic organs. In our report, a 18F-fluorodeoxyglucose positron emission tomography scan of a mediastinal mass infiltrating the lungs and of widespread lesions suggested the presence of a metastatic disease. Open thoracic biopsy was required for immunochemistry and histopathology. Mediastinal mass with lesions disseminated throughout the body is an unusual presentation of extranodal RDD that calls for a challenging differential diagnosis to rule out the suspicion of metastatic malignancy.

The role of macrophages in interstitial lung diseases: Number 3 in the Series "Pathology for the clinician" Edited by Peter Dorfmüller and Alberto Cavazza.

The finding of collections of macrophages/histiocytes in lung biopsy and bronchoalveolar lavage is relatively common in routine practice. This morphological feature in itself is pathological, but the exact clinical significance and underlying disease should be evaluated together with clinical data, functional respiratory and laboratory tests and imaging studies.Morphological characteristics of macrophages and their distribution along the different pulmonary structures should be examined carefully by pathologists. Indeed, haemosiderin-laden macrophages are associated with smoking-related diseases when pigment is fine and distribution is bronchiolocentric, while alveolar haemorrhage or pneumoconiosis are the main concerns when pigment is chunky or coarse and the macrophages show an intra-alveolar or perilymphatic location, respectively. In the same way, pulmonary accumulation of macrophages with foamy cytoplasm is generally associated with pathologies leading to broncho-bronchiolar obstruction (e.g. diffuse panbronchiolitis, hypersensitivity pneumonia or cryptogenic organising pneumonia) or alternatively to exogenous lipoid pneumonia, some drug toxicity (e.g. amiodarone exposure or toxicity) and metabolic disorders (e.g. type B Niemann-Pick disease).This pathology-based perspectives article is aimed at concisely describing the diagnostic possibilities when faced with collection of macrophages in lung biopsy and cytology.

Thymus neuroendocrine tumors with CTNNB1 gene mutations, disarrayed ß-catenin expression, and dual intra-tumor Ki-67 labeling index compartmentalization challenge the concept of secondary high-grade neuroendocrine tumor: a paradigm shift.

We herein report an uncommon association of intimately admixed atypical carcinoid (AC) and large cell neuroendocrine (NE) carcinoma (LCNEC) of the thymus, occurring in two 20- and 39-year-old Caucasian males. Both tumors were treated by maximal thymectomy. The younger patient presented with a synchronous lesion and died of disease after 9 months, while the other patient was associated with a recurrent ectopic adrenocorticotropic hormone Cushing's syndrome and is alive with disease at the 2-year follow-up. MEN1 syndrome was excluded in either case. Immunohistochemically, disarrayed cytoplasmic and nuclear ß-catenin expression was seen alongside an intra-tumor Ki-67 antigen labeling index (LI) ranging from 2 to 80% in the younger patient's tumor and from 3 to 45% in the other. Both exhibited upregulated cyclin D1 and retinoblastoma, while vimentin was overexpressed in the recurrent LCNEC only. Next-generation sequencing revealed CTNNB1, TP53, and JAK3 mutations in the synchronous tumor and CTNNB1 mutation alone in the metachronous tumor (the latter with the same mutation as the first tumor of 17 years prior). None of the 23 T-NET controls exhibited this hallmarking triple alteration (p = 0.003). These findings suggested that LCNEC components developed from pre-existing CTNNB1-mutated AC upon loss-of-function TP53 and gain-of-function JAK3 mutations in one case and an epithelial-mesenchymal transition upon vimentin overexpression in the other case. Both tumors maintained intact cyclin D1-retinoblastoma machinery. Our report challenges the concept of secondary LCNEC as an entity that develops from pre-existing AC as a result of tumor progression, suggesting a paradigm shift to the current pathogenesis of NET.

Asymptomatic Pulmonary Allograft Kaposi Sarcoma: A Case Report.

Solid-organ transplant recipients are at high risk of developing malignancies. A greater risk of Kaposi sarcoma has been reported in lung recipients in our country, particularly in those from Southern Italy, probably due to the high prevalence of Human herpes virus 8 infection. Kaposi sarcoma affecting only the lung allograft is extremely rare. We describe a case of a lung recipient who developed Kaposi sarcoma only in the graft, 22 months after transplant. The patient, a 65-year-old man from Southern Italy, underwent bilateral lung transplant for idiopathic pulmonary fibrosis in January 2009. He developed mild/moderate acute cellular rejection (≥A2) in 4 of 6 scheduled transbronchial biopsies thus was treated with increased immunosuppressive therapy, shifting from cyclosporine to tacrolimus and mycophenolate mofetil. In July 2010, a high-resolution computed tomography scan showed small bilateral lung nodules, despite a generally good condition. After 2 months, his condition worsened with a severe weight loss. A positron emission tomography scan showed mild metabolic activity in the lesions with no other localizations. In October 2010, a lung biopsy was performed, with results showing typical histologic and immunohistochemical features of Kaposi sarcoma. Molecular tissue evaluations and serologic analyses were positive for Human herpes virus 8. The patient's immunosuppressive therapy was suspended, and he started liposomal doxorubicin treatment; however, after the first cycle, he developed severe respiratory dysfunction. The patient died 27 months after lung transplant for neoplasm. Our report highlights the importance of considering Kaposi sarcoma in the differential diagnosis for lung nodules in lung transplant recipients, even in the absence of any initial specific symptom or cutaneous lesion.

Idiopathic pulmonary fibrosis: Are any of the morphological-molecular markers useful in clinical management?

Idiopathic pulmonary fibrosis (IPF), the most common form of chronic interstitial lung disease, is a severe progressive fibrotic disorder of unknown aetiology. The disease has a heterogeneous clinical course, with frequent poor prognosis, similar to malignant disease. Correctly diagnosing IPF has become particularly important in view of the availability of more precise therapeutic indications, thus avoiding steroid treatment and allowing new approaches with novel drugs. To date we have limited information about biomarkers predictive of progressive disease and associated complications. Efforts should be made in the future to more appropriately study lung tissue and then to extrapolate the most clinically fitting biomarkers. This approach is already used in routine management of many cancers and provides a potential road map for more appropriate clinical care of IPF. This review will mainly focus on histology and etiopathogenesis highlighting some morphological and molecular features that may influence the overall management of IPF.

Conflicting or complementary role of computed tomography (CT) and positron emission tomography (PET)/CT in the assessment of thymic cancer and thymoma: our experience and literature review.

BACKGROUND: To evaluate the role of computed tomography (CT) and positron emission tomography (PET)/CT in patients with thymic cancer and thymoma at initial staging. METHODS: We retrospectively reviewed CT and PET/CT scans of 26 patients with a thymic cancer (n = 9) or thymoma (n = 17). Chest CT findings documented were qualitative and quantitative. Both qualitative and semiquantitative data were recovered by PET/CT. The comparisons among histological entities, outcome, and qualitative data from CT and PET/CT were made by non-parametric analysis. RESULTS: PET/CT resulted positive in 15/17 patients with thymoma. CT was available in 5/9 (56%) patients with thymic cancer and in 3/17 with thymoma. All quantitative CT parameters were significantly higher in patients with thymic cancer than thymoma (maximum axial diameter: 45 vs. 20 mm, maximum longitudinal diameter: 69 vs. 21 mm and volume: 77.91 vs. 4.52 mL; all P < 0.05). Conversely, only metabolic tumor volume (MTV) and total lesion glycolysis were significantly different in patients with thymic cancer than thymoma (126.53 vs. 6.03 cm3 and 246.05 vs. 20.32, respectively; both P < 0.05). After a median follow-up time of 17.45 months, four recurrences of disease occurred: three in patients with thymic cancer and one with a type B2 thymoma. CT volume in patients with recurrent disease was 102.19 mL versus a median value of 62.5 mL in six disease-free patients. MTV was higher in the recurrent than disease-free patient subset (143.3 vs. 81.13 cm(3)), although not statistically significant (P = 0.075). CONCLUSION: Our preliminary results demonstrated that both morphological and metabolic volume could be useful from a diagnostic and prognostic point of view in thymic cancer and thymoma patients. A large multi-center clinical trial experience for confirming the findings of this study seems mandatory.

A 72-Year-Old Woman With Previous Pulmonary Metastasis and New Peripheral Nodule.

A 72-year-old female nonsmoker was admitted to our Thoracic Surgery Unit in 2013 because of a lesion detected on chest CT scan during oncologic follow-up. Her medical history was significant for the development of a single pulmonary metastasis discovered 1 year after sigmoidectomy for colic adenocarcinoma. At that time, the patient was treated with six cycles of neoadjuvant chemotherapy followed by left lower lobectomy. Histologic examination demonstrated a pulmonary metastasis of colic adenocarcinoma with diffuse necrotic areas. The patient underwent subsequent adjuvant chemotherapy with capecitabine and was followed annually with biohumoral oncologic screening (carcinoembryonic antigen, carbohydrate antigen 19-9), chest-abdomen CT scan, and colonoscopy.

Higher Risk of Acute Cellular Rejection in Lung Transplant Recipients with Cystic Fibrosis.

BACKGROUND Acute cellular rejection (ACR) affects up to 40% of recipients within the first year after lung transplant (LTx). The aim of this study was to determine the frequency of ACR and associated major risk factors in cystic fibrosis (CF) recipients. Bronchiolitis obliterans syndrome (BOS) and 1-year/long-term survival were also evaluated. MATERIAL AND METHODS ACR was reviewed in 643 scheduled biopsies from 44 CF (Group 1) versus 89 other recipients (Group 2). We performed univariate/multivariate analyses of risk factors for ACR and BOS, and survival analysis. RESULTS Group 1 showed higher ACR frequency, especially for ACR ≥ A2. Multivariable generalized linear models considering both native lung disease and age showed that higher values of ACR index were significantly related to the pretransplant diagnosis of CF. BOS and long-term survival were not influenced by the increased incidence of ACR. Poorer long-term survival was observed in Group 2. CONCLUSIONS CF recipients have a higher ACR risk, which may be due to enhanced immune activation related to a genetic disorder, and younger age.

COPD-related adenocarcinoma presents low aggressiveness morphological and molecular features compared to smoker tumours.

OBJECTIVES: Adenocarcinoma comprises a group of diseases with heterogeneous clinical and molecular characteristics. COPD and lung cancer are strictly related; to date it is unknown if COPD-associated cancers have different features from tumours arising in non-COPD patients. Our aim was to study COPD-associated adenocarcinoma phenotypes mainly focusing on morphological and molecular aspects, in comparison to smoke-related cancer without COPD. MATERIALS AND METHODS: From 2010 to 2013, 54 patients with adenocarcinoma (20 COPD and 34 smokers) were prospectively studied. Each patient underwent a complete clinical and instrumental assessment. Morphological studies included analysis of growth pattern, cell proliferation (Ki-67/MIB1 expression) and parameters of intra- and peri-tumoral remodelling (inflammation, fibrosis and necrosis). Genetic analysis of EGFR and KRAS mutations was also performed. RESULTS: The two groups were comparable for the main demographic and biohumoral parameters except for increased blood basophil cell count in the COPD group. Compared to COPD, tumours of smokers presented an increased percentage of solid component (median: 20% vs 5%, p=0.02), a reduced percentage of lepidic pattern (median: 0% vs 10%, p=0.06) and higher Ki-67/MIB1 median value (55% vs 30%, p=0.02). In multivariate analysis lepidic and solid histological pattern were significantly influenced by clinical group (p=0.03 and 0.05, respectively). Concerning EGFR mutation, no differences were found between groups while KRAS mutation presented a trend of higher percentage in smokers compared to COPD (41% vs 20%, p=NS). Adenocarcinoma with KRAS mutation showed a higher value of Ki-67/MIB1 (65% vs 35%, p=0.048) and prevalent solid pattern (35% vs 10%, p=0.019) in comparison to wild-type form. CONCLUSIONS: COPD-related adenocarcinoma presents molecular and morphological features of lower aggressiveness (increased lepidic component, reduced solid pattern, lower cell proliferation and less frequent KRAS mutation) compared to smokers. Different molecular mechanisms could be associated with the development of COPD associated cancer.

Synergistic antitumor activity of recombinant human Apo2L/tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in combination with carboplatin and pemetrexed in malignant pleural mesothelioma.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is an aggressive, currently incurable tumor with increasing incidence in industrialized countries. Tumor necrosis factor-related, apoptosis-inducing ligand (TRAIL) is a member of the TNF family, which induces cancer cell death through extrinsic apoptotic pathway, while sparing normal cells. The aim of this study was to investigate the antitumor activity of recombinant human Apo2L/TRAIL (dulanermin) in combination with chemotherapy in MPM in vitro and in vivo. METHODS: In the present studies, we employed a panel of MPM cell lines to test the antitumor activity of recombinant human Apo2L/TRAIL (T) in combination with carboplatin and pemetrexed (CP) in vitro and SCID mice. RESULTS: Results demonstrated a significant increase of apoptosis in cell lines treated with CPT compared with those receiving CP or T as single agents. This synergistic effect was dependent on the ability of CP to increase the expression of the TRAIL receptors DR4 and DR5 in a p53 manner. The CPT combination was also effective in blocking the growth of MPM cell lines in a SCID mice preclinical model. CONCLUSIONS: CPT increases MPM cell death in vitro and in vivo compared with CP. In vitro results suggest that chemotherapy sensitizes MPM to TRAIL-dependent apoptosis through p53 activation and subsequent upregulation of DRs.

Necrotizing sarcoid granulomatosis with an uncommon manifestation: clinicopathological features and review of literature.

We report a rare case of an incidental diagnosis of necrotizing sarcoid granulomatosis (NSG) in a 60-y-old non-smoking male. The patient was admitted to the hospital for sudden back pain. Chest x-ray revealed areas of parenchymal consolidation and high-resolution computed tomography demonstrated a pulmonary nodular pattern with no lymph node enlargement. All laboratory and pulmonary function tests were normal. Bronchoscopy with bronchoalveolar lavage showed no sign of infection or specific inflammation. The diagnosis of NSG was made by histopathological examination of a surgical lung biopsy and by excluding other causes of granulomatous disease. In paucisymptomatic/asymptomatic patients, as in our case, therapy is not necessary, with a good prognosis and complete recovery. NSG is a rare systemic disease similar to sarcoidosis and Wegener's granulomatosis with a benign clinical course and should always be considered for patients with nodular pulmonary lesions even with subclinical or uncommon features.

The mitochondrial chaperone TRAP1 promotes neoplastic growth by inhibiting succinate dehydrogenase.

We report that the mitochondrial chaperone TRAP1, which is induced in most tumor types, is required for neoplastic growth and confers transforming potential to noncancerous cells. TRAP1 binds to and inhibits succinate dehydrogenase (SDH), the complex II of the respiratory chain. The respiratory downregulation elicited by TRAP1 interaction with SDH promotes tumorigenesis by priming the succinate-dependent stabilization of the proneoplastic transcription factor HIF1α independently of hypoxic conditions. These findings provide a mechanistic clue to explain the switch to aerobic glycolysis of tumors and identify TRAP1 as a promising antineoplastic target.

Localized pleuropulmonary crystal-storing histiocytosis: 5 cases of a rare histiocytic disorder with variable clinicoradiologic features.

Crystal-storing histiocytosis (CSH) localized to the thoracic region is a rare occurrence, often secondary to lymphoproliferative or plasma cell diseases. About 10 case reports have been previously published, and 3 of these have no relationship with clonal hematologic disorders. We collected here the first series of 5 consecutive cases of CSH involving lungs (4 cases) and pleura (1 case). There were 3 women and 2 men with a mean age at diagnosis of 65 years. All cases had an underlying hematologic disorder (2 B-cell marginal-zone lymphomas, 2 monoclonal gammopathy of undetermined significance and 1 pulmonary plasmacytoma). Despite a common morphology characterized by a dense and irregular growth of large eosinophilic histiocytes with intracytoplasmic refractile crystals, 2 cases presented with cystic changes at gross and imaging examinations, calcified amyloid was found in 2 cases, and 1 case showed an interstitial lung disease with nonspecific interstitial pneumonia pattern. Histiocytes were immunoreactive for CD68 (clones PGM-1 and KP-1) but were not for CD1a and S100; the associated lymphoplasmacellular disorder had a clonal profile on molecular analysis with κ light-chain restriction. Two cases were originally misdiagnosed as cystic fibrohistiocytic tumor and carcinoid tumor, thus confirming that CSH localized to this site may result in a diagnostic challenge with a broad spectrum of differential diagnoses. The presence of intracytoplasmic crystals and a plasma cell infiltrate around a histiocytic proliferation should alert the pathologist to consider CSH and to carefully investigate the presence of clonal hematologic disease.

Herpes virus infection is associated with vascular remodeling and pulmonary hypertension in idiopathic pulmonary fibrosis.

BACKGROUND: Pulmonary hypertension (PH) represents an important complication of idiopathic pulmonary fibrosis (IPF) with a negative impact on patient survival. Herpes viruses are thought to play an etiological role in the development and/or progression of IPF. The influence of viruses on PH associated with IPF is unknown. We aimed to investigate the influence of viruses in IPF patients focusing on aspects related to PH. A laboratory mouse model of gamma-herpesvirus (MHV-68) induced pulmonary fibrosis was also assessed. METHODS: Lung tissue samples from 55 IPF patients and 41 controls were studied by molecular analysis to detect various viral genomes. Viral molecular data obtained were correlated with mean pulmonary arterial pressure (mPAP) and arterial remodelling. Different clinical and morphological variables were studied by univariate and multivariate analyses at time of transplant and in the early post-transplant period. The same lung tissue analyses were performed in MHV-68 infected mice. RESULTS: A higher frequency of virus positive cases was found in IPF patients than in controls (p = 0.0003) and only herpes virus genomes were detected. Viral cases showed higher mPAP (p = 0.01), poorer performance in the six minute walking test (6MWT; p = 0.002) and higher frequency of primary graft (PGD) dysfunction after lung transplant (p = 0.02). Increased arterial thickening, particularly of the intimal layer (p = 0.002 and p = 0.004) and higher TGF-ß expression (p = 0.002) were demonstrated in viral cases. The remodelled vessels showed increased vessel cell proliferation (Ki-67 positive cells) in the proximity to metaplastic epithelial cells and macrophages. Viral infection was associated with higher mPAP (p = 0.03), poorer performance in the 6MWT (p = 0.008) and PGD (p = 0.02) after adjusting for other covariates/intermediate factors. In MHV-68 infected mice, morphological features were similar to those of patients. CONCLUSION: Herpesviral infections may contribute to the development of PH in IPF patients.

Serpin B4 isoform overexpression is associated with aberrant epithelial proliferation and lung cancer in idiopathic pulmonary fibrosis.

AIMS: The aim of the study was to evaluate the role of Serpin B3/B4 in advanced idiopathic pulmonary fibrosis (IPF) patients, mainly focusing on epithelial proliferation. METHODS: Lungs from 48 IPF patients (including cases with cancer or high-grade epithelial dysplasia) were studied and compared with other diffuse parenchymal diseases and normal lungs. Immunohistochemistry for Serpin B3/B4 and Ki-67 was quantified in all cases, distinguishing stained metaplastic cells. In IPF patients correlations between Serpin expression and several clinicopathological data, including fibrotic remodelling [fibrosis extension and transforming growth factor ß expression (TGF-ß)] were performed. Molecular analysis was used for Serpin isoform characterisation. RESULTS: In IPF patients Serpin B3/B4 and Ki-67 were significantly overexpressed in many metaplastic cells (mainly squamous type) compared to control cases. Higher Serpin B3/B4 was found in older patients and cases with more impaired respiratory function. Serpin B3/B4 expression was related to both TGF-ß and Ki-67 and was higher in patients with cancer/high-grade dysplasia. Serpin B3 was expressed in all cases, whereas Serpin B4 was expressed only in IPF. CONCLUSIONS: Serpin B3/B4, particularly Serpin B4, appears to play an important role in aberrant epithelial proliferation. Evaluation of Serpin B3/B4 could have prognostic value in predicting disease progression, especially in patients with increased susceptibility to lung cancer.

Clear cell carcinoid of the appendix: an uncommon variant of lipid-rich neuroendocrine tumor with a broad differential diagnosis.

The designation of clear cell/lipid-rich refers to an unusual variant of neuroendocrine tumor ("carcinoid") described in several organs, but only recently observed in the appendix. In this study, we report the morphologic, immunohistochemical, and ultrastructural features of an incidentally discovered appendiceal clear cell/lipid-rich carcinoid in a 32-year-old man without any evidence of von Hippel-Lindau disease. Differential diagnosis with mimicking neoplastic and non-tumor lesions, epidemiology, and clinical behavior of this exceedingly rare variant of carcinoid of the appendix are also discussed.