Background Primary endobronchial smooth muscle tumors (SMTs), which are extremely rare, include endobronchial leiomyomas and leiomyosarcomas. Clinically, SMTs present with signs and symptoms of bronchial obstruction, and lack specific radiological findings. Thus, histopathological examination is required for accurate diagnosis as well as for tumor grading. We examined the histomorphological and immunohistochemical features of endobronchial SMTs and highlighted pitfalls in diagnosis, particularly when using small biopsies.
Methods Cases of primary endobronchial SMTs diagnosed at our Institute over the last 6 years (2012–2017) were retrieved from the departmental archives. Histopathological features and immunohistochemistry performed for establishing the diagnosis were reviewed.
Results Five cases of SMTs occurring in endobronchial locations were identified. These included three cases of leiomyoma, and two cases of leiomyosarcoma. The age distribution of patients ranged from 13 to 65 years. Leiomyomas showed more consistent staining with smooth muscle markers (smooth muscle actin, desmin, and smooth muscle myosin heavy chain), while tumors of higher grade showed variable, focal staining, leading to erroneous diagnosis, especially on small biopsies.
Conclusions The diagnosis of endobronchial SMTs relies on histopathological examination, for both confirmation of smooth muscle lineage and determination of the malignant potential of the lesion. Appropriate immunohistochemical panels including more than one marker of smooth muscle differentiation are extremely valuable for differential diagnosis from morphological mimics, which is necessary for instituting appropriate management.
Citations
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Case report: Successful bronchoscopic interventional treatment of endobronchial leiomyomas Yinfeng Wang, Yixiang Zhang, Ruirui Tong Open Life Sciences.2024;[Epub] CrossRef
Pediatric endobronchial tumors with a mimicker: A case series Kulwiwat Promsawasdi, Teerasak Phewplung Pediatric Pulmonology.2024; 59(10): 2669. CrossRef
Smooth Muscle Conditions of the Chest Matthew R. McCann, Lucas R. Massoth, Carlos A. Rojas, Yin P. Hung, John P. Lichtenberger, Gerald F. Abbott, Justin T. Stowell Journal of Thoracic Imaging.2021; 36(5): 263. CrossRef
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Actinomycosis causes a chronic suppurative infection most commonly involving the cervico-facial region, thorax, and the abdomen. Thoracic infection results from an aspiration of contaminated material from mouth or oropharynx. Actinomyces was known to have a predilection for the periphery of the lung and the endobronchial lesion is extremely rare. We report two cases of actinomycosis presenting as an endobronchial mass which arose in 53-year-old and 44-year-old women. The first case presented with cough, sputum, weight loss and had a history of pulmonary tuberculosis 24 years ago.
Chest CT revealed a right lobe collapse simulating mass and suggested carcinoma. The second case presented with hemoptysis for 2 years. Chest CT revealed cystic bronchiectasis of both lungs and intracystic soft tissue mass in the anterior segment of the right upper lobe which suggested aspergilloma. The gross features of them were similar to those of aspergilloma. Characteristic sulphur granules consisting of a granular basophilic center surrounded by a radiating zone of eosinophilic, hyaline, club-shaped projection were histologically confirmed in both cases.
Granulomas containing P.
westermani eggs were present in the second case.
Staphylococcus, true fungal organism, nocardia, and streptomyces shoud be distinguished by analysing their morphologic characteristics in the appropriate stains. Actinomycosis should be included in the differential diagnoses of an endobronchial mass.
Inflammatory pseudotumors of the bronchus have been reported infrequently. Histologic diagnosis remains difficult because of their Polymorphic histologic characteristics and confusing terminology, which are also the problems in the diagnosis of intrapulmonary pseudotumors. We report a case of inflammatory pseudotumor in the left main bronchus which occurred in a 37-year-old man. Histologically, the main portion of the tumor was composed of pale eosinophilic spindle shaped cells covered by respiratory epithelium with squamous metaplasia. Mononuclear inflammatory cells, including plasma cells but acute inflammatory cells were also present in the superficial portion.
Endobronchial tuberculosis is granulomatous inflammation of the bronchial mucosa characterized by bronchial ulceration due to caseous necrosis. There is a good chance to expectorate cellular components of granulomas in the sputum.
The author studied a cytologic series from 46 patients with endo-bronchial tuberculosis confirmed on fiberoptic bronchoscopic biopsy. The cytologic series consisted of 32 sputa, 41 washings, and 17 bronchial brushings, and were carefully screened for elongated epithelioid cells, Langhan's type giant cells, other multinucleated giant cells and caseous material. Elongated epithelioid cells were demonstrated in 9 sputa (28.1%), 30 bronchial washings (73.2%) and 11 brushing smears (64.7%). Langhans' giant cells were observed in two of 32 sputa (6.2%), six of 41 bronchial washings (14.6%) and four of 17 bronchial brushings (23.5%). The caseous materials were noted in 19 of 32 sputa (59.4%), 32 of 41 bronchial washings (78.0%), and 14 of 17 bronchial burshings (82.4%). It appeared that the pertinent cellular components of granulomas in sputa or bronchial secretions indicated a strong evidence of endobronchial tuberculosis of the lung.