[Pulmonary blastomycosis]. / Blastomycose pulmonaire.

Blastomycosis is a rare fungal disease in Africa which is often due to inhalation of "Blastomyces dermatitidis". Pulmonary blastomycosis is the most common clinical manifestation which presents with a variety of clinical features, ranging from asymptomatic to rapidly fatal. We report the case of a Tunisian patient aged 35 years with no previous medical history, hospitalized with chronic cough, bilateral basithoracic pain, fever and weight loss. Clincal examination showed fever and left paravertebral subcutaneous swelling next to the tenth thoracic vertebra (T10). Chest imaging objectified bilateral alveolar and nodular opacities with excavations in some places. Sputum stain for Koch bacillus (BK) was negative (direct examination and culture). Bronchial fibroscopy was normal. Anatomopathological examination of dorsal mass biopsy revealed blastomycosis. The diagnosis was confirmed by cultures of the biopsic fragments of the mass. Antifungal therapy with itraconazole was started with clinical and radiological improvement. This case study highlights challenges in the diagnosis of blastomycosis in our country, in particular when lesions mimick tuberculosis; hence delayed therapy.

Classifying multiple lung cancers using morphological features: a meta-analysis.

Multiple lung cancers may be intrapulmonary metastases or multiple primaries. Management and prognosis of both entities are different and make the pathologist's role challenging. In fact, distinguishing both entities may be difficult especially when the tumors present the same microscopic subtype. The microscopic diagnoses of these tumors have been improved based on the 2015 WHO classification. The aim of the authors was to assess the diagnostic value of morphologic features in comparison to the gold standard test represented by molecular testing in the distinction between intrapulmonary metastases and multiple lung primaries. To retrieve all eligible articles, PubMed and Embase databases and Cochrane Library were comprehensively searched from 1999 to 2020 with limitation to French andEnglish language. The Meta-Disc software 5.1.32 was used to conduct this meta-analysis. The pSEN, pSPE, NLR, PLR, and DOR with the 95% confidence intervals were calculated. The area under the SROC was calculated based on the SEN and SPE of each study. Q test and I2 statistics were carried out to explore the heterogeneity among studies. P value <.1 for q test or I2 value >50% represented substantial between-study heterogeneity. Meta-regressions were performed to explore the sources of heterogeneity if necessary. Twelve eligible articles with 309 patients were included. pSEN was estimated to 65% with I-square estimated to 53%. pSPE reached 49% with I-square estimated to 56%. PLR was estimated to 1.23 with I-square estimated to 33%. NLR was estimated to 0.65 with I-square estimated to 23.1%. dOR was estimated to 2.13 [1.07-4.25] with I-square estimated to 26.5%. AUC was estimated to 0.63. The meta-regression analysis showed non-significant effect of the WHO classification, next-generation sequencing, or nucleotide-specific sequencing with p reaching respectively 0.38, 0.06, and 0.36. These results highlight that morphologic features may be useful in the diagnosis of multiple lung cancers especially when dealing with surgical specimen. The mild heterogeneity observed in this meta-analysis may be due to other covariates that were not described in the different articles including the sample nature.

About the diagnostic value of BAP-1 antibody in malignant pleural mesothelioma: a meta-analysis.

BACKGROUND: The positive diagnosis of MPM is based on morphologic features coupled with immunohistochemical findings. Many antibodies have been published especially in order to differentiate between malignant tumors and atypical mesothelial hyperplasia. BAP-1 is a BRCA1-binding protein whose loss of expression was frequently reported in MPM. Our aim was to assess the diagnostic value of this antibody in comparison to the most sensitive diagnostic antibody represented by the calretinin antibody. METHODS: We performed a meta-analysis using the Meta-Disc software 5.1.32. RESULTS: According to our inclusion criteria, 19 studies with 11 studies dealing with BAP1 antibody and 8 studies dealing with calretinin antibody were included. The SEN of BAP 1 and calretinin antibodies was respectively estimated to 54.6% and 86.5%. The SPE reached respectively 95.7% and 76.6%. The dOR was estimated respectively to 23.664 and 38.8. The I-square revealed a heterogeneity of the parameters studied. The metaregression analysis revealed as covariates the amplification system and the histologic subtype as causing effects of heterogeneity for BAP1 antibodies and histologic subtype and chromogene as causing effects of heterogeneity for calretinin antibody. CONCLUSION: This meta-analysis revealed that BAP1 antibody should be associated with more sensitive antibodies in order to assess the diagnosis.

The utility of bronchoalveolar lavage in the evaluation of interstitial lung diseases: A clinicopathological perspective.

Bronchoalveolar lavage (BAL) is a noninvasive and well-tolerated procedure that is performed with a fiberoptic bronchoscope in the wedged position within a selected bronchopulmonary segment. After it was introduced to clinical practice, BAL rapidly gained acceptance in a large number of centers as a procedure that could be applied to the clinical evaluation of patients with various pulmonary disorders, especially the group of interstitial lung diseases (ILD). Cytological and flow cytometric analysis of BAL fluid in ILD is done with knowledge of the clinical presentation and radiological findings. BAL typically reveals variations in the types and numbers of nucleated immune cells and acellular components in patients with ILD, which differ from those seen in normal control subjects. Many clinicians currently use this technique as a guide in the differential diagnoses of ILD; it can also be used to monitor the course of disease and possible response to therapeutic interventions. This article summarizes current clinicopathological information concerning the use of BAL by pulmonologists and pathologists.

How to assess the best immunohistochemical panel in the diagnosis of malignant pleural mesothelioma in a pathology lab.

BACKGROUND: malignant pleural mesothelioma (MPM) is a rare tumor with a challenging diagnosis. Even if, clinical data are mandatory to suspect the diagnosis, the positive diagnosis is based on microscopic features. Morphologic features are still the port of call of the diagnosis but their non specific character and the multiplicity of differential diagnoses made the immunohistochemical markers mandatory for the diagnosis. Many antibodies with a positive diagnostic value including claretinin, mesothelin, WT1 and antibodies with a negative diagnostic value including TTF1, EMA, CD15 are recommended by the scientific societies. This is due to the diagnostic limits of every antibody which necessitate the association of multiple antibodies. In the diagnostic demarch, pathologists deal with different antibodies and clones. Even if many recommendations are available, every pathology lab has to experiment its own antibodies in order to optimize the routine diagnostic demarch especially in low-income country. Our aim was to assess the diagnostic value of different antibodies available in our lab and to recommend a decisional flowchart. PATIENTS AND METHODS: we conducted a retrospective study about 30 MPM diagnosed over a 20-year-period. The different techniques were realized manually. The different antibodies used were anti-calretinin, anti-Epithelial Membrane Antigen (EMA), anti-mesothelin, anti-Thyroid Transcription Factor 1 (TTF1), anti-ACE, anti-cytokeratin, anti-vimentin, anti-CD15, anti-cytokeratin 5/6, anti-bcl2, and anti-CD99 and anti-CD34 antibodies. The sensitivity and specificity of these antibodies were assessed. RESULTS: the microscopic exam concluded to an epithelioid mesothelioma (EM) in 17 cases, sarcomatoid mesothelioma (SM) in four cases and biphasic mesothelioma (BM) in nine cases. The immunohistochemical study was performed in all cases. A mean of eight antibodies was used in every case, average 4 to 20 antibodies. The immunohistochemical study was repeated from 2 to 5 times in 15 cases and concerned a mean of 3 antibodies per case. In EM and BM, the antibodies with positive predictive value and highest sensitivity were calretinin, EMA, cytokeratin, and vimentin reaching respectively a sensitivity of 86.2%, 89.7%, 92.9% and 89.3%. The most valuable antibodies with negative predictive value were TTF1, CD15 and ACE that presented a specificity reaching respectively 100%. In sarcomatoid mesothelima, the most sensitive antibody was the cytokeratin antibody. CONCLUSION: these results yielded to a diagnostic flowchart that we can use in routine practice and that is in accordance with the literature findings. Many diagnostic and technical pitfalls have to be known by pathologists when dealing with MPM.

[Which technique should be used in the phenotyping of lymphocytic alveolitis: Immunocytochemistry or flow cytometry]. / Quelle technique adopter pour le phénotypage des alvéolites lymphocytaires : immunocytochimie ou cytométrie en flux ?

BACKGROUND: Diffuse interstitial pneumonias are considered as a group of multiple affections characterized by challenging diagnoses because of the lack of specific clinical signs. Radiologic investigations highlight the diagnoses in most of the cases but bronchoalveolar lavage plays a key role in the diagnostic diagram. We aim to compare the immunocytochemical technique and the flow cytometry in the phenotyping of lymphocytic alveolitis. METHODS: We described a series of 32 lymphocytic alveolitis, which were analyzed using immunocytochemistry and flow cytometry. RESULTS: We found a good reproducibility between the immunocytochemistry performed on smears and cytoblocks (kappa=0.7) and a poor reproducibility between immunocytochemistry and flow cytometry (kappa=0.35). CONCLUSION: Our study emphasized on the poor reproducibility between immunocytochemistry and flow cytometry. Further studies about the reliability of both techniques are needed especially in discordant cases.

[Post-traumatic fibro-osseous lesion of the rib]. / Lésion fibro-osseuse post-traumatique de la côte : une entité rare à ne pas méconnaître.

Post-traumatic fibro-osseous lesion is a rare benign osseous lesion usually affecting the ribs and relatively under-recognised. Histologically, it showed a bland fibrous stroma in which resided an anastomosing network of bone trabeculae, having a zonal pattern of maturation from metaplastic woven to mature lamellar bone, with or without an associated xanthomatous component. We report a well-documented case of mixed variant post-traumatic fibro-osseous lesion of the sixth rib, which was initially misdiagnosed as particular form of fibrous dysplasia associated with a xanthoma.