DNA methylation as a new tool for the differential diagnosis between T-LBL and lymphocyte-rich thymoma.

T-lymphoblastic lymphoma (T-LBL) and thymoma are two rare primary tumors of the thymus deriving either from T-cell precursors or from thymic epithelial cells, respectively. Some thymoma subtypes (AB, B1, and B2) display numerous reactive terminal deoxynucleotidyl transferase-positive (TdT+) T-cell precursors masking epithelial tumor cells. Therefore, the differential diagnosis between T-LBL and TdT+ T-lymphocyte-rich thymoma could be challenging, especially in the case of needle biopsy. To distinguish between T-LBL and thymoma-associated lymphoid proliferations, we analyzed the global DNA methylation using two different technologies, namely MeDIP array and EPIC array, in independent samples series [17 T-LBLs compared with one TdT+ lymphocyte-rich thymoma (B1 subtype) and three normal thymi, and seven lymphocyte-rich thymomas compared with 24 T-LBLs, respectively]. In unsupervised principal component analysis (PCA), T-LBL and thymoma samples clustered separately. We identified differentially methylated regions (DMRs) using MeDIP-array and EPIC-array datasets and nine overlapping genes between the two datasets considering the top 100 DMRs including ZIC1, TSHZ2, CDC42BPB, RBM24, C10orf53, and MACROD2. In order to explore the DNA methylation profiles in larger series, we defined a classifier based on these six differentially methylated gene promoters, developed an MS-MLPA assay, and demonstrated a significant differential methylation between thymomas (hypomethylated; n = 48) and T-LBLs (hypermethylated; n = 54) (methylation ratio median 0.03 versus 0.66, respectively; p < 0.0001), with MACROD2 methylation status the most discriminating. Using a machine learning strategy, we built a prediction model trained with the EPIC-array dataset and defined a cumulative score taking into account the weight of each feature. A score above or equal to 0.4 was predictive of T-LBL and conversely. Applied to the MS-MLPA dataset, this prediction model accurately predicted diagnoses of T-LBL and thymoma. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

A novel Chr1-miR-200 driven whole transcriptome signature shapes tumor immune microenvironment and predicts relapse in early-stage lung adenocarcinoma.

BACKGROUND: In Lung adenocarcinoma (LUAD), targeted therapies and immunotherapies have moved from metastatic to early stage and stratification of the relapse risk becomes mandatory. Here we identified a miR-200 based RNA signature that delineates Epithelial-to-mesenchymal transition (EMT) heterogeneity and predicts survival beyond current classification systems. METHODS: A miR-200 signature was identified using RNA sequencing. We scored the miR-200 signature by WISP (Weighted In Silico Pathology), used GSEA to identify pathway enrichments and MCP-counter to characterize immune cell infiltrates. We evaluate the clinical value of this signature in our series of LUAD and using TCGA and 7 published datasets. RESULTS: We identified 3 clusters based on supervised classification: I is miR-200-sign-down and enriched in TP53 mutations IIA and IIB are miR-200-sign-up: IIA is enriched in EGFR (p < 0.001), IIB is enriched in KRAS mutation (p < 0.001). WISP stratified patients into miR-200-sign-down (n = 65) and miR-200-sign-up (n = 42). Several biological processes were enriched in MiR-200-sign-down tumors, focal adhesion, actin cytoskeleton, cytokine/receptor interaction, TP53 signaling and cell cycle pathways. Fibroblast, immune cell infiltration and PDL1 expression were also significantly higher suggesting immune exhaustion. This signature stratified patients into high-vs low-risk groups, miR-200-sign-up had higher DFS, median not reached at 60 vs 41 months and within subpopulations with stage I, IA, IB, or II. Results were validated on TCGA data on 7 public datasets. CONCLUSION: This EMT and miR-200-related prognostic signature refines prognosis evaluation independently of tumor stage and paves the way towards assessing the predictive value of this LUAD clustering to optimize perioperative treatment.

Clinical assessment of the miR-34, miR-200, ZEB1 and SNAIL EMT regulation hub underlines the differential prognostic value of EMT miRs to drive mesenchymal transition and prognosis in resected NSCLC.

BACKGROUND: Patients with non-small cell lung cancer (NSCLC) receiving curative surgery have a risk of relapse, and adjuvant treatments only translate into a 5% increase in 5-year survival. We assessed the clinical significance of epithelial-mesenchymal transition (EMT) and explored its association with the [SNAIL/miR-34]:[ZEB/miR-200] regulation hub to refine prognostic information. METHODS: We validated a 7-gene EMT score using a consecutive series of 176 resected NSCLC. We quantified EMT transcription factors, microRNAs (miRs) of the miR-200, miR-34 families and miR-200 promoter hypermethylation to identify outcome predictors. RESULTS: Most tumours presented with an EMT-hybrid state and the EMT score was not predictive of outcome. Individually, all miR-200 were inversely associated with the EMT score, but only chromosome-1 miRs, miR-200a, b, 429, were associated with disease-free survival (p = 0.08, 0.05 and 0.025) and overall survival (p = 0.013, 0.003 and 0.006). We validated these associations on The Cancer Genome Atlas data. Tumour unsupervised clustering based on miR expression identified two good prognostic groups, unrelated to the EMT score, suggesting that miR profiling may have an important clinical value. CONCLUSION: miR-200 family members do not have similar predictive value. Core EMT-miR, regulators and not EMT itself, identify NSCLC patients with a low risk of relapse after surgery.

Vascular Ehlers-Danlos syndrome (vEDS): CT and histologic findings of pleural and lung parenchymal damage.

OBJECTIVES: To describe CT features of lung involvement in patients with vascular Ehlers-Danlos syndrome (vEDS), a rare genetic condition caused by pathogenic variants within the COL3A1 gene, characterized by recurrent arterial, digestive, and pulmonary events. MATERIAL AND METHODS: All consecutive vEDS patients referred to the national tertiary referral center for vEDS, between 2004 and 2016, were included. Chest CT scans obtained during the initial vascular work-up were reviewed retrospectively by two chest radiologists for lung involvement. Five surgical samples underwent histologic examination. RESULTS: Among 136 enrolled patients (83 women, 53 men; mean age 37 years) with molecularly confirmed vEDS, 24 (17.6%) had a history of respiratory events: 17 with pneumothorax, 4 with hemothorax, and 3 with hemoptysis that required thoracic surgery in 11. CT scans detected lung parenchymal abnormalities in 78 (57.3%) patients: emphysema (mostly centrilobular and paraseptal) in 44 (32.3%), comparable for smokers and non-smokers; clusters of calcified small pulmonary nodules in 9 (6.6%); and cavitated nodules in 4 (2.9%). Histologic examination of surgical samples found arterial abnormalities, emphysema with alveolar ruptures in 3, accompanied by diffuse hemorrhage and increased hemosiderin resorption. CONCLUSION: In vEDS patients, identification of lung parenchymal abnormalities is common on CT. The most frequently observed CT finding was emphysema suggesting alveolar wall rupture which might facilitate the diagnostic screening of the disease in asymptomatic carriers of a genetic COL3A1 gene mutation. The prognostic value and evolution of these parenchymal abnormalities remain to be evaluated. KEY POINTS: • Patients with vEDS can have lung parenchymal changes on top of or next to thoracal vascular abnormalities and that these changes can be present in asymptomatic cases. • The presence of these parenchymal changes is associated with a slightly higher incidence of respiratory events (although not statistically significant). • Identification of the described CT pattern by radiologists and chest physicians may facilitate diagnostic screening.

[Toxic hydroxychloroquine-induced cardiomyopathy complicating systemic lupus treatment]. / Cardiomyopathie toxique induite par l'hydroxychloroquine compliquant le traitement d'un lupus systémique.

Hydroxychloroquine (HCQ) is considered as efficient and safe to treat systemic lupus. We report a case of fatal toxic cardiomyopathy, an underrecognized adverse effect of HCQ. A 72-year-old woman with systemic lupus erythematosus treated for 24 years by HCQ received a kidney allograft. One year later she developed a cardiomyopathy with conductive disorders. An endomyocardial biopsy showed severe non-specific myocardial fibrosis and hypertrophic vacuolated myocytes. Transmission electron microscopy showed curvilinear bodies and pseudomyelin figures consistent with HCQ-induced cardiomyopathy. At immunohistochemistry LC3b, p62 and beclin-1 accumulated in vacuolated cardiac myocytes suggesting impaired cell autophagy. When unexplained cardiac disease develops in patients receiving long-term HCQ treatment, toxic cardiomyopathy should be considered leading to a diagnostic endomyocardial biopsy.

In situ BCL2 expression is an independent prognostic factor in HIV-associated DLBCL, a LYMPHOVIR cohort study.

The prognostic value of cell of origin (COO) classification and BCL2 expression is not well established in diffuse large B-cell lymphoma (DLBCL) patients with human immunodeficiency virus (HIV) infection in the recent era. Phenotypic patterns were determined by immunohistochemistry (IHC) of pathological samples from patients with HIV-associated DLBCL prospectively enrolled in the French AIDS and Viral Hepatitis CO16 Lymphovir cohort between 2008 and 2015. Molecular subgroup classification into germinal centre B-cell (GCB) and non-GCB subtypes was determined using the Hans algorithm. Among 52 samples of systemic DLBCL subjected to centralized pathological analysis, 25 of the 42 tested for BCL2 expression were positive. Samples were further classified into GCB (n = 19) and non-GCB (n = 16) subtypes and 17 remained unclassified. In multivariable analysis, BCL2 expression was an independent pejorative prognostic biomarker [4-year progression-free survival (PFS): 52% for BCL2+ vs. 88% for BCL2- , P = 0·02] and tended to reduce 4-year overall survival (OS) (63% for BCL2+ vs. 88% for BCL2- , P = 0·06). The difference between CGB and non-GCB subtypes on PFS and OS did not reach significance (4-year PFS: 79% for GCB vs. 53% for non-GCB, P = 0·24 and 4-year OS: 78% for GCB vs. 69% for non-GCB, P = 0·34). BCL2 expression determined by IHC is an independent pejorative prognostic biomarker in HIV-associated DLBCL in the recent era. This supports the investigation of new therapeutic strategies in patients with BCL2 expression.

[Guidelines for the macroscopic management of surgically resected lung carcinoma]. / Recommandations SFP pour la prise en charge macroscopique des pièces de résections de tumeurs pulmonaires.

Gross examination is an essential step for pathological report of a surgical sample. It includes the description of the surgical specimen and their disease(s), the precise and exhaustive sampling of tumoral and adjacent tumoral tissue areas. This examination requires a good knowledge of the updated pTNM classification. Pathologists from the PATTERN group have collaborated with thoracic surgeons, under the auspices of the Sociéte française de pathologie, to propose guidelines for resected specimen management. This approach fits into the context of the elaboration of structured pathological report proposed by the société française de pathologie, which is necessary for a standardized management of patients.

[PD-L1 testing in non-small cell lung carcinoma: Guidelines from the PATTERN group of thoracic pathologists]. / Tests immunohistochimiques PD-L1 dans les cancers du poumon non à petites cellules : recommandations par le groupe PATTERN de pathologistes thoraciques.

Lung cancer is the leading cause of cancer death in France with low response rates to conventional chemotherapy. Nevertheless, new therapies have emerged recently, among which PD1 immune checkpoint inhibitors (ICI), such as nivolumab (OPDIVO®, Bristol-Myers Squibb) and pembrolizumab (KEYTRUDA®, Merck & Co), or PD-L1 ICI, such as atezolizumab (TECENTRIQ®, Genentech), durvalumab (IMFINZI®, Astra-Zeneca), and avelumab (BAVENCIO®, EMD Serono). The prescription of pembrolizumab for advanced stage non-small cell lung carcinoma (NSCLC) patients requires the demonstration of PD-L1 expression by tumor cells by immunohistochemistry (IHC) (minimum of 50% of positive tumor cells is required for first-line setting, and of 1% for second-line and beyond) and PD-L1 assay is now considered as a companion diagnostic tool for this drug. Numerous standardized PD-L1 assays performed on dedicated platforms have been validated in clinical trials, each antibody being associated to one specific PD1 or PD-L1 inhibitor. However, not all pathologists have access to the dedicated platforms and the high cost of these assays is still a limitation to their implementation; in addition, the small size of the NSCLC tumor samples does not allow to perform at the same time multiple assays for multiple drugs. The use of laboratory-developed tests seems feasible but their validation must guarantee the same sensitivities and specificities as standardized tests. In this context, the French group of thoracic pathologists PATTERN has teamed up with thoracic oncologists to provide recommendations on the indication, the critical technical steps and the interpretation of the PD-L1 IHC test to help pathologists to implement quickly and in the best conditions this new theranostic test.

Morphologic and molecular study of lung cancers associated with idiopathic pulmonary fibrosis and other pulmonary fibroses.

BACKGROUND: Primitive lung cancers developed on lung fibroses are both diagnostic and therapeutic challenges. Their incidence may increase with new more efficient lung fibrosis treatments. Our aim was to describe a cohort of lung cancers associated with idiopathic pulmonary fibrosis (IPF) and other lung fibrotic disorders (non-IPF), and to characterize their molecular alterations using immunohistochemistry and next-generation sequencing (NGS). METHODS: Thirty-one cancer samples were collected from 2001 to 2016 in two French reference centers for pulmonary fibrosis - 18 for IPF group and 13 for non-IPF group. NGS was performed using an ampliseq panel to analyze hotspots and targeted regions in 22 cancer-associated genes. ALK, ROS1 and PD-L1 expressions were assessed by immunohistochemistry. RESULTS: Squamous cell carcinoma was the most frequent histologic subtype in the IPF group (44%), adenocarcinoma was the most frequent subtype in the non-IPF group (62%). Forty-one mutations in 13 genes and one EGFR amplification were identified in 25 samples. Two samples had no mutation in the selected panel. Mutations were identified in TP53 (n = 20), MET (n = 4), BRAF (n = 3), FGFR3, PIK3CA, PTEN, STK11 (n = 2), SMAD4, CTNNB1, DDR2, ERBB4, FBXW7 and KRAS (n = 1) genes. No ALK and ROS1 expressions were identified. PD-L1 was expressed in 10 cases (62%) with only one (6%) case >50%. CONCLUSIONS: This extensive characterization of lung fibrosis-associated cancers evidenced molecular alterations which could represent either potential therapeutic targets either clues to the pathophysiology of these particular tumors. These findings support the relevance of large molecular characterization of every lung fibrosis-associated cancer.

Doege-Potter syndrome: hypoglycaemic coma in a 90-year old due to a solitary fibrous tumour.

Solitary fibrous tumour of the pleura (SFTP) is a rare primary tumour of the pleura associated with 4% of cases with a paraneoplastic hypoglycaemia, termed Doege-Potter syndrome (DPS). We report a case of DPS presenting with severe coma in a 90-year-old woman. The cause was a malignant SFTP treated with surgical resection, from which the patient made a full recovery with prevention of recurrent hypoglycaemia. Surgical resection of the SFTP presenting with symptomatic hypoglycaemia should be considered even in elderly patients.

Fatal Pulmonary Mucormycosis due to Rhizopus homothallicus.

We report here a case of cavitary pneumonia due to Rhizopus homothallicus in a diabetic patient. This is the first proven case of R. homothallicus infection in Western countries and the third case described worldwide. The organism was isolated from lung biopsy and identified after amplification and sequencing of the internal transcribed spacer region.

[Efficacy of PD-1/PD-L1 immune checkpoint inhibitors and PD-L1 testing in thoracic cancers]. / Efficacité des inhibiteurs du checkpoint immunitaire PD-1/PD-L1 et testing PD-L1 dans les cancers thoraciques.

Tumoral immune environment is a major component of cancer. Its composition and its organization represent a reproducible characteristic of tumors and a validated prognostic factor. In non-small cell lung cancer (NSCLC), cytotoxic T CD8+ lymphocyte density, associated with a Th1 environment and tertiary lymphoid structures impacts survival. Tumor cell-immune cell interaction is targeted by PD1/PD-L1 inhibitors. In advanced NSCLC, PD1/PD-L1 inhibitors are more effective than second-line chemotherapy. Pembrolizumab outperforms first-line chemotherapy in NSCLC strongly positive for PD-L1. PD1/PD-L1 inhibitors are currently tested in mesothelioma and thymic tumors. PD-L1 expression evaluated with immunochemistry is the most studied predictive biomarker of PD1/PD-L1 inhibitor efficacy. Tumor and immune cell expression of PD-L1 is still difficult to evaluate because of intra-tumoral heterogeneity and expression modulation by the microenvironment. Four commercial diagnostic antibodies are in development, with differences concerning recognized epitopes, methodology of evaluation of PD-L1 expression, positivity threshold, kit and platforms used. Clinical trials in NSCLC have shown that patients with tumors strongly positive for PD-L1 derived the best clinical benefit with PD1/PD-L1 inhibitors whereas clinical benefit is less common in tumors negative for PD-L1. PD-L1 expression is not a perfect biomarker since some PD-L1 negative NSCLC respond to PD1/PD-L1 inhibitors and some PD-L1 positive NSCLC do not. PD-L1 testing is likely to be implemented in daily practice for selection of advanced NSCLC that will be treated with pembrolizumab, underscoring the relevance of ongoing harmonization studies of the use of the different antibodies available for PD-L1 testing.

[The "immune checkpoints", how does it work]. / Les « immune checkpoints ¼, comment ça marche.

Costimulatory molecules allow the full lymphocyte activation, whereas co-inhibitory molecules are negative counterparts that act as immune regulators, avoiding excessive response. In some context of chronic inflammation such as cancer, co-inhibitory immune checkpoint as CTLA-4, PD-1, Lag-3, Tim-3 can accumulate at the membrane of T cells leading to a state of anergy and therefore the loss of tumor growth control. Consequently, these immune checkpoints are considered as potential target in the treatment of cancer. Immunotherapy by anti-CTLA-4 and anti-PD-1/PD-L1 early demonstrated very good proof of efficacy in the setting of several cancers types, supporting the role of these molecules in tumor immune escape. The aim of this review is to summarize the pathophysiology of immune checkpoints and their therapeutic applications in cancer.

Base-Position Error Rate Analysis of Next-Generation Sequencing Applied to Circulating Tumor DNA in Non-Small Cell Lung Cancer: A Prospective Study.

BACKGROUND: Circulating tumor DNA (ctDNA) is an approved noninvasive biomarker to test for the presence of EGFR mutations at diagnosis or recurrence of lung cancer. However, studies evaluating ctDNA as a noninvasive "real-time" biomarker to provide prognostic and predictive information in treatment monitoring have given inconsistent results, mainly due to methodological differences. We have recently validated a next-generation sequencing (NGS) approach to detect ctDNA. Using this new approach, we evaluated the clinical usefulness of ctDNA monitoring in a prospective observational series of patients with non-small cell lung cancer (NSCLC). METHODS AND FINDINGS: We recruited 124 patients with newly diagnosed advanced NSCLC for ctDNA monitoring. The primary objective was to analyze the prognostic value of baseline ctDNA on overall survival. ctDNA was assessed by ultra-deep targeted NGS using our dedicated variant caller algorithm. Common mutations were validated by digital PCR. Out of the 109 patients with at least one follow-up marker mutation, plasma samples were contributive at baseline (n = 105), at first evaluation (n = 85), and at tumor progression (n = 66). We found that the presence of ctDNA at baseline was an independent marker of poor prognosis, with a median overall survival of 13.6 versus 21.5 mo (adjusted hazard ratio [HR] 1.82, 95% CI 1.01-3.55, p = 0.045) and a median progression-free survival of 4.9 versus 10.4 mo (adjusted HR 2.14, 95% CI 1.30-3.67, p = 0.002). It was also related to the presence of bone and liver metastasis. At first evaluation (E1) after treatment initiation, residual ctDNA was an early predictor of treatment benefit as judged by best radiological response and progression-free survival. Finally, negative ctDNA at E1 was associated with overall survival independently of Response Evaluation Criteria in Solid Tumors (RECIST) (HR 3.27, 95% CI 1.66-6.40, p < 0.001). Study population heterogeneity, over-representation of EGFR-mutated patients, and heterogeneous treatment types might limit the conclusions of this study, which require future validation in independent populations. CONCLUSIONS: In this study of patients with newly diagnosed NSCLC, we found that ctDNA detection using targeted NGS was associated with poor prognosis. The heterogeneity of lung cancer molecular alterations, particularly at time of progression, impairs the ability of individual gene testing to accurately detect ctDNA in unselected patients. Further investigations are needed to evaluate the clinical impact of earlier evaluation times at 1 or 2 wk. Supporting clinical decisions, such as early treatment switching based on ctDNA positivity at first evaluation, will require dedicated interventional studies.

Analysis of Base-Position Error Rate of Next-Generation Sequencing to Detect Tumor Mutations in Circulating DNA.

BACKGROUND: Detecting single-nucleotide variations and insertions/deletions in circulating tumor DNA is challenging because of their low allele frequency. The clinical use of circulating tumor DNA to characterize tumor genetic alterations requires new methods based on next-generation sequencing. METHODS: We developed a method based on quantification of error rate of each base position [position error rate (PER)]. To identify mutations, a binomial test was used to compare the minor-allele frequency to the measured PER at each base position. This process was validated in control samples and in 373 plasma samples from patients with lung or pancreatic cancer. RESULTS: Minimal mutated allele frequencies were 0.003 for single-nucleotide variations and 0.001 for insertions/deletions. Independent testing performed by droplet digital PCR (n = 231 plasma samples) showed strong agreement with the base-PER method (κ = 0.90). CONCLUSIONS: Targeted next-generation sequencing analyzed with the base-PER method represents a robust and low cost method to detect circulating tumor DNA in patients with cancer.

[Salivary gland-type lung tumor: An update]. / Tumeurs de type glandes salivaires du poumon.

"Salivary gland-type" tumors arising from the bronchi and lung are rare but not exceptional entities. They are mostly represented by malignant entities such as cystic adenoid carcinoma, mucoepidermoid carcinoma and epithelial/myoepithelial carcinoma. Benign tumors are rare, mainly encompassing pleomorphic adenomas, which are to differentiate from mucous gland adenomas, another entity arising specifically from the peri-bronchial glands. These tumours develop in the proximal bronchi and are not associated with smoke abuse. Their main treatment is surgery. It is important to differentiate them from other broncho-pulmonary tumours as they do not share the same prognosis and therapeutic. This article will review the WHO 2015 classification of these tumours as well as recent updates from the literature to help define diagnosis criteria for these uncommon entities.

Successive next-generation sequencing strategy for optimal fusion gene detection in non-small-cell lung cancer in clinical practice.

Metastatic non-small-cell lung cancer (NSCLC) displays various molecular alterations in the RAS-MAPK pathway. In particular, NSCLCs show high rates of targetable gene fusion in ALK, RET, ROS1, NRG1 and NTRK, or MET exon 14 skipping. Rapid and accurate detection of gene fusion in EGFR/KRAS/BRAF mutations is important for treatment selection especially for first-line indications. RNA-based next-generation sequencing (NGS) panels appear to be the most appropriate as all targets are multiplexed in a single run. While comprehensive NGS panels remain costly for daily practice, optimal sequencing strategies using targeted DNA/RNA panel approaches need to be validated. Here, we describe our lung cancer screening strategy using DNA and RNA targeted approaches in a real-life cohort of 589 NSCLC patients assessed for molecular testing. Gene fusions were analysed in 174 patients negative for oncogene driver mutations or ALK immunohistochemistry in a two-step strategy. Targetable alterations were identified in 28% of contributive samples. Non-smokers had a 63.7% probability to have a targetable alteration as compared to 21.5% for smokers. Overall survival was significantly higher (p=0.03) for patients who received a molecularly matched therapy. Our study shows the feasibility in routine testing of NSCLC DNA/RNA molecular screening for all samples in a cost- and time-controlled manner. The significant high fusion detection rate in patients with wild-type RAS-MAPK tumours highlights the importance of amending testing strategies in NSCLC.

Infectious native aortic aneurysm with negative blood cultures: do not forget the pneumococcal urinary antigen test!

Infectious native aortic aneurysm (INAA) are rare but life-threatening infections. Early microbiological identification is crucial to initiate adequate therapy and decrease the peri-operative risk, but can be challenging when blood cultures remain negative. We describe two cases of pneumococcal INAA with negative blood cultures, diagnosed in the with the pneumococcal urinary antigen test.

Transbronchial cryobiopsy proven amyloid diffuse cystic lung disease complicating a transthyretin mutated (ATTRm) amyloidosis: a case report.

We present a case report of transbronchial cryobiopsy proven diffuse amyloid cystic lung disease complicating a homozygous Val122Ile (V122I) transthyretin mutated amyloidosis (ATTRm). To the best of our knowledge, this is the first case in the literature reporting such pulmonary lesions in ATTRm amyloidosis, and notably diagnosed through cryobiopsy. A 51-year-old man from Mali with a past medical history of bilateral carpal tunnel syndrome presented erectile dysfunction, asthenia and worsening dyspnoea over the past year. He presented signs of cardiac failure; histological and radiological investigations diagnosed cardiac amyloidosis. He was found homozygote for the V122I mutation in transthyretin. A diffuse cystic lung disease (DCLD) was noted on computed tomography (CT) scan. We performed a transbronchial pulmonary cryobiopsy that revealed histological transthyretin amyloid deposits. This case report illustrates the safety and usefulness of cryobiopsy in the setting of DCLD and extends ATTRm amyloidosis as a possible cause of DCLD.