Granulomatosis with polyangiitis is a form of vasculitis that affects the kidneys and the lower and upper respiratory tracts, and progresses with pathologically necrotizing granulomatous inflammation. Patients can present with such nonspecific symptoms as malaise, fever, weight loss and hemoptysis. Diagnosis is based on radiological, pathological and laboratory examinations. Lung involvement usually presents in the form of bilateral nodules, and cavitary lesions and pulmonary infiltrates may also be seen. Tuberculosis and granulomatosis with polyangiitis share common clinical symptoms, radiological findings and immunopathological features. In our country, where the incidence of tuberculosis (TB) is high, necrotizing granulomatous inflammation are often evaluated initially as TB. We present here two cases of nodular lung disease to draw attention to the need for careful differential diagnosis between granulomatosis with polyangiitis and tuberculosis.

This case report presents an uncommon manifestation of microscopic polyangiitis (MPA) characterized by an initial reversed halo sign (RHS) on chest computed tomography (CT). A 49-year-old female patient with a history of sensorineural hearing loss presented with progressive respiratory symptoms. Comprehensive clinical investigations, including chest CT, laboratory tests and renal biopsy, confirmed a diagnosis of MPA, and targeted treatment with glucocorticoids and cyclophosphamide resulted in significant improvement in the lung lesions. This report aims to increase clinical awareness of atypical presentations of MPA and to reduce potential diagnostic challenges.

Sjögren’s syndrome (SS) is a chronic autoimmune disease characterized by systemic involvement that primarily affects the exocrine glands. Although pulmonary involvement is often asymptomatic, it can present with interstitial lung disease, airway abnormalities and, in rare cases, pulmonary amyloidosis and lymphoma. A 69-year-old female with a history of SS and a previous diagnosis of extranodal marginal zone B-cell lymphoma (EMZBCL) following a parotidectomy presented with pleuritic chest pain and unintentional weight loss. Imaging revealed multiple pulmonary nodules and ground-glass opacities, and the nodules were assessed to be at high risk for malignancy. A biopsy and segmentectomy decision was made based on a multidisciplinary evaluation of PET-CT findings, and the resulting pathology revealed EMBCL and widespread AL amyloidosis. Chemotherapy was subsequently planned. This case highlights that pulmonary involvement in SS can remain hidden, requiring the careful monitoring of pulmonary symptoms in recognition of the high malignancy risk. A multidisciplinary approach can play a critical role in the management of such complex cases.

Cryptogenic Organizing Pneumonia (COP) is a lung disease characterized by multiple areas of consolidation with a subpleural distribution or ground-glass opacities, various atypical presentations of which have been reported in the literature. A 47-year-old male who presented with a cough underwent thoracic computed tomography, revealing multiple bilateral pulmonary nodules, located predominantly in the upper lobes. The nodules, the largest of which measured 20 mm, had varying border characteristics and some had frosted-glass densities. Positron emission tomography/computed tomography revealed several small lymph nodes without mediastinal pathological FDG uptake. A large number of nodules were identified in both lung parenchyma, some of which were calcified and with mildly elevated FDG uptake (early SUV max: 2.18, late SUV max: 3.14). The patient presented with an unusual radiological pattern of bilateral pulmonary nodules mimicking pulmonary metastases, however, histopathological findings were consistent with COP. This case highlights how the radiological and nuclear imaging characteristics of COP can potentially lead to misdiagnosis, such as malignancy.

Invasive pulmonary aspergillosis (IPA) is typically seen in immunocompromised patients, but may also develop in immunocompetent individuals, and is associated with high mortality rates. We report here on the case of a 47-year-old male patient with a history of asthma who presented with fever, cough and sputum production. He was initially diagnosed with hospital-acquired pneumonia and started on appropriate treatment, however, his symptoms persisted. Further investigations revealed Aspergillus spp., leading to a diagnosis of invasive aspergillosis. Radiological imaging revealed a lesion in the left upper lobe, and the diagnosis was confirmed through transthoracic needle biopsy. The patient was started on intravenous voriconazole, but developed thrombosis in the right cephalic vein. Anticoagulation therapy with enoxaparin was added to the protocol, however, balancing the treatment of thrombosis with the risk of bleeding presented a challenge. This case highlights the challenges that can be encountered in clinical diagnosis and treatment, and shows that aspergillosis should be considered even in immunocompetent patients. It further clarifies the need to find the optimum balance between thrombosis treatment and bleeding risk, as a critical aspect of the treatment process in cases of invasive aspergillosis.

A 41-year-old woman with Anaplastic Lymphoma Kinase (ALK) gene positive adenocarcinoma of the lung presented with dyspnea in the 4th month of Crizotinib therapy with a prominent finding of bilateral mild pleural effusion. A comprehensive radiological and laboratory investigation discounted infection, rheumatological diseases and malignancies, while the symptoms and pleural effusion regressed after pausing Crizotinib medication. We present this unusual case of lymphocytic pleural effusion associated with Crizotinib, which is a novel tyrosine kinase inhibitor.

The solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm derived from CD34+ dendritic stromal cells, primarily found in the pleura but also occurring in other sites like the lung and peritoneum. It accounts for approximately 5% of pleural tumors. Respiratory symptoms, such as cough and dyspnea, typically result from the compression of adjacent structures. The treatment of choice remains surgical, involving complete excision of the tumor, often requiring extensive resections. The prognosis is generally favorable for benign forms, although postoperative monitoring is crucial due to a risk of recurrence, particularly in more aggressive cases; surgery should also be considered in the event of local recurrence, if technically feasible. This study aims to analyze the clinical presentation, pathological findings, and outcomes of five patients diagnosed with SFT, emphasizing the importance of early diagnosis and effective management.

Myiasis has been more frequently studied as an animal disease caused by fly larvae, although it may also affect humans. Bacteria and viruses are the most common nosocomial pathogens in intensive care units, although it is necessary to be aware of the potential for nosocomial parasitic infections. We present here a case of oral myiasis in a 96-year-old patient with Alzheimer's disease who was intubated while being treated for aspiration pneumonia. Our intention in this regard is to clarify the specific clinical features of the disease, especially hospital-acquired myiasis, and to raise awareness of the potential for nosocomial parasitic infections among physicians, as preventable and treatable diseases.

Birt-Hogg-Dubé Syndrome (BHDS) is characterized by benign cutaneous lesions in the head and neck region, pulmonary cysts or spontaneous pneumothorax. It is a rare disorder associated with a mutation in the folliculin (FLCN) gene. A 53-year-old male patient who presented with exertional dyspnea was identified with multiple cystic lesions in a computed tomography (CT) scan, as well as pneumothorax in the right lung. The patient presented again 2 years later complaining of left-side chest pain, and left-sided pneumothorax was identified on imaging. The patient had 2–3 mm papules on his shoulders, cheeks and forehead, and a pathological examination confirmed a diagnosis of trichodiscoma. The patient, who had bullous lung disease, trichodiscoma and a positive FLCN gene sequencing result, was diagnosed with BHDS. We share this case to emphasize the need to consider BHDS in the differential diagnosis of rare cystic lung diseases in patients presenting with recurrent pneumothorax and distinctive cutaneous findings.