Risks of segmentectomy for interstitial pneumonia with diffuse pulmonary ossification.

An 84-year-old man with a history of progressive interstitial pneumonia presented to our department with lung cancer (cT2aN0M0-IB) in right S6. Moreover, computed tomography revealed progressive diffuse pulmonary ossification in the bilateral lower pulmonary lobes. S6 segmentectomy was performed via video-assisted thoracoscopic surgery. It was difficult to divide the intersegmental plane using a stapler because of severe fibrosis and pulmonary ossification with bone marrow formation. Pulmonary ossification may be an important finding for surgical planning because of severe fibrosis or inflammation associated with severe lung condition. We suggest that the surgical indications and approaches for such cases should be reconsidered because pulmonary ossification can be associated with severe lung conditions.

Idiopathic dendriform pulmonary ossification as the phenotype of interstitial lung abnormalities: CT-pathologic correlation and prevalence.

BACKGROUND AND PURPOSE: Idiopathic dendriform pulmonary ossification (DPO) is mostly asymptomatic, and detected incidentally in lung CT. There have been no reports on the precise CT-pathologic correlation and the prevalence of idiopathic DPO. This study aimed to clarify the histological background and prevalence of idiopathic DPO. MATERIALS AND METHODS: Sixteen patients with histologically confirmed idiopathic DPO (12 men and 4 women; mean age, 38.8 years; range 22-56 years) were identified in a nationwide epidemiological survey. Local HRCT findings of pre-biopsy examinations, such as branching, round, linear structures with or without high attenuation were compared side by side with histological findings. The attenuation of branching, round, and linear structures was classified into three-point levels on bone window images (width, 2500 HU; level, 500 HU). Furthermore, we collected continuous pulmonary CT images of 8111 cases for checking up metastasis from extrathoracic malignancy at a single institution, and evaluated the prevalence of interstitial lung abnormalities (ILAs) and DPO. RESULTS: In all 16 cases, branching (n = 15, 93%), round (n = 5, 31%), or linear (n = 5, 31%) structures were identified, histologically corresponding to dendriform ossification and cicatricial organizing pneumonia (OP)/fibrosis. Histologically, ossification was confirmed in all the 16 patients. However, in two cases, a highly attenuated structure could not be detected on the pre-biopsy CT of the same area. Regarding the prevalence of idiopathic DPO, 283 (3.5%) of 8111 patients had ILAs, of which a total of 26 (0.3% of all cases, 9.2% of ILAs cases) had DPO. CONCLUSION: Idiopathic DPO showed linear or branching structures with or without high attenuation on CT, corresponded to ossification, cicatricial OP/fibrosis. DPO was seen in 9.2% of ILAs cases. Idiopathic DPO is one of pathologic phenotypes of ILAs.

An Autopsy Case of COVID-19 with New Diffuse Pulmonary Ossification.

We present the case of a 61-year-old man who developed coronavirus disease 2019 (COVID-19) and died during treatment for relapsing polychondritis. The patient was intubated and treated with steroid pulse therapy, remdecivir, antibacterial agents, baricitinib, and tocilizumab. However, his respiratory condition worsened, and he died 108 days after disease onset. An autopsy revealed diffuse alveolar damage in the fibrotic phase in all lung lobes, diffuse pulmonary ossification, and cytomegalovirus-infected cells in the middle lobe of the right lung. We herein discuss the clinical features and pathological findings of COVID-19 in immunosuppressed patients.

Myeloid osseous metaplasia of the lung: A case report.

Pulmonary osseous metaplasia is a disease in which mature bone is found within the parenchyma of the lung. The current study presents a case of pulmonary osseous metaplasia in a 64-year-old female. The patient was previously diagnosed with transitional cell carcinoma (TCC) of the lower ureter. During a routine check-up, an enhancing basal lung nodule was found on chest computed tomography scan, which was suspected to be metastatic lung disease. The patient underwent a thoracoscopic resection of the nodule. The histopathological examination of the specimen confirmed it to be myeloid osseous metaplasia. The disease usually has no significant complications and can also be found in association with other pulmonary diseases. Very limited information is available on the phenomenon; therefore, there is no exact treatment guide for clinicians to follow. In conclusion, myeloid osseous metaplasia of the lung is a rare finding, and based on this report, it may be associated with TCC.

Idiopathic Fibrotic Nonspecific Interstitial Pneumonia with Cicatricial Organizing Pneumonia and Intraluminal Pulmonary Ossification Containing Bone Marrow.

A 72-year-old man presented with bilateral ground-glass opacities in the lower lung fields on chest radiography. Computed chest tomography showed ground-glass opacities and micronodules in both lower lungs. A video-assisted thoracoscopic biopsy of the right lower lung showed homogeneous thickening of the alveolar septa with fibrosis and inflammatory cell infiltration consistent with fibrotic non-specific interstitial pneumonia (fNSIP). Cicatricial organizing pneumonia and intraluminal pulmonary ossification containing bone marrow that was considered to represent dendriform pulmonary ossification. Idiopathic fNSIP was diagnosed. The patient remains stable under antifibrotic treatment.

Diffuse pulmonary ossification: A case report unveiling clinical and histopathological challenges.

Diffuse pulmonary ossification (DPO) is a rare pulmonary condition characterized by the diffuse formation of mature bone in the lungs. Pulmonary ossification, in general, can be subdivided into diffuse pulmonary ossification (DPO) and nodular pulmonary ossification (NPO). DPO occurs most commonly in the settings of chronic pulmonary conditions; however, idiopathic cases have been reported. We present a case of DPO in a 36-year-old man with progressive exertional dyspnea, productive cough, and occasional hemoptysis. Imaging studies showed innumerable pulmonary nodules scattered throughout both lungs. Initially, the diagnoses of pulmonary alveolar microlithiasis (PAM) or, less likely miliary tuberculosis (TB) were considered. However, Quantiferon TB test was negative and genetic testing was negative for SLC34A2, lowering the probability of PAM. The patient underwent a segmentectomy. Microscopic examination showed ramifying spicules of mature woven bone and fatty marrow consistent with DPO. There were no significant underlying pathologic findings, such as interstitial fibrosis, granulomas, organizing pneumonia, or significant inflammation in the background lung parenchyma. In conclusion, clinicians and radiologists need to be aware of DPO in the differential diagnosis of miliary tuberculosis and pulmonary alveolar microlithiasis. The absence of an underlying chronic pulmonary condition does not exclude the possibility of DPO.

Interstitial Pulmonary Fibrosis and Extensive Dendriform Ossification with Persistent Viral Load: A Rare Presentation of Post-COVID-19 Condition in Need of Lung Transplantation.

The incidence, presentation, and predisposing factors of post-acute sequelae of COVID-19 (PASC) are currently poorly understood. Lung explants may provide a rare insight into terminal SARS-CoV-2-associated lung damage and its pathophysiology. A 62-year-old man presented with progressively worsening respiratory symptoms after recovering from mild COVID-19 3 months earlier. No underlying pulmonary comorbidities were reported. A chest CT revealed bilateral extensive ground-glass and reticular opacities, suspicious of pulmonary fibrosis. Despite initial high-dose glucocorticoid therapy, the interstitial lung disease progressed, and after exhausting all viable therapeutic options, bilateral lung transplantation was successfully conducted. Histological analysis revealed extensive end-stage interstitial fibrosis with diffuse dendriform ossification and bronchiolar and transitional cell metaplasia. Signs of interstitial remodeling such as an increased interstitial collagen deposition, a pathological accumulation of CD163+/CD206+ M2-polarized macrophages with an increased expression of phosphorylated ERK, and an increased density of CD105+ newly formed capillaries were observed. qRT-PCR and immunohistochemistry for SARS-CoV-2 N-protein in the endothelium of medium-sized vessels confirmed a persistence of SARS-CoV-2. Our findings highlight a highly unusual presentation of SARS-CoV-2-associated lung fibrosis, implying that incomplete viral clearance in the vascular compartment may play a vital pathophysiological role in the development of PASC.

A rare case and review of pulmonary ossification.

Pulmonary ossification (PO) is a rare metastatic disease characterized by the formation of diffuse heterotopic bone units in the lung parenchyma. Herein, we describe a 45-year-old Filipino male with dendriform pulmonary ossification in combination with gastroesophageal reflux disease and chronic dust exposure, a notably unique association. Radiographic imaging and pathology findings are examined with discussion of various pulmonary disease entities from current literature. Further recognition of PO will facilitate appropriate treatment and better outcomes for patients diagnosed with this enigmatic condition.

Proceedings of the 2022 National Toxicology Program Satellite Symposium.

The 2022 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri," was held in Austin, Texas at the Society of Toxicologic Pathology's 40th annual meeting during a half-day session on Sunday, June 19. The goal of this symposium was to present and discuss challenging diagnostic pathology and/or nomenclature issues. This article presents summaries of the speakers' talks along with select images that were used by the audience for voting and discussion. Various lesions and topics covered during the symposium included induced and spontaneous neoplastic and nonneoplastic lesions in the mouse lung, spontaneous lesions in the reproductive tract of a female cynomolgus macaque, induced vascular lesions in a mouse asthma model and interesting case studies in a rhesus macaque, dog and genetically engineered mouse model.

Nothing but lung and bones: Longitudinal evolution and quantitative analysis in a case of idiopathic diffuse pulmonary ossification.

A 77-year-old Caucasian man, a former surveyor in a chemical company, underwent a chest X-ray (CXR) as a follow-up exam for a melanoma of the back, surgically removed. CXR showed interstitial thickening in both lower lobes; then, a high-resolution computed tomography of the chest (HRCT) was performed to further investigate these findings, revealing multiple small, calcified nodules with branching appearance at both lung bases. Clinical examination and exposure history were negative, except for a decrease in diffusing capacity for carbon monoxide resulting from pulmonary function tests. Surgical lung biopsy was performed; histology revealed numerous nodules and branching tubules of bone tissue, some of which with marrow elements. After multidisciplinary discussion of the case, a diagnosis of idiopathic diffuse pulmonary ossification (DPO) was considered. Clinical status of the patient was stable over time, despite the increase in extent of calcifications. DPO is an uncommon condition that should be considered in different clinical-radiological settings; multidisciplinary discussion is essential for the final diagnosis.