A Case of Thoracic Empyema Caused by Actinomyces naeslundii.

BACKGROUND Actinomycosis is a clinically significant but uncommon infectious disease caused by anaerobic commensals of Actinomyces species, and the incidence of thoracic empyema is rare. We report an extremely rare case of empyema caused by Actinomyces naeslundii (A. naeslundii). CASE REPORT A 39-year-old man presented to our hospital with fever and dyspnea. He had massive pleural effusion and was diagnosed with a left lower-lobe abscess and left thoracic empyema. Thoracic drainage was performed and Ampicillin/Sulbactam was administered for 3 weeks. Four years later, the patient presented with back pain, and chest X-ray showed increased left pleural effusion. After close examination, malignant pleural mesothelioma was suspected, and computed tomography-guided needle biopsy was performed, which yielded a viscous purulent pleural effusion with numerous greenish-yellow sulfur granules. A. naeslundii was identified through anaerobic culture. Thoracoscopic surgery of the empyema cavity was conducted, and Ampicillin/Sulbactam followed by Amoxicillin/Clavulanate was administered for approximately 6 months. No recurrence has been observed for 1 year since the surgical procedure. CONCLUSIONS Actinomyces empyema is a rare condition, and this case is the second reported occurrence of empyema caused by A. naeslundii. The visual identification of sulfur granules contributed to the diagnosis. Long-term antibiotic therapy plays a crucial role in treatment.

Intrapulmonary solitary fibrous tumor with malignant potential: A case report.

Intrapulmonary solitary fibrous tumor is rare, and its clinical course has not been sufficiently reported. We presented a case of an 80-year-old male non-smoker and discussed the surgical procedure selection and the recurrence risk assessment. A solid nodule, 1.1 cm in diameter, was identified in the left lower lobe on chest computed tomography and showed no accumulation on positron emission tomography. A wedge resection with a sufficient surgical margin under video-assisted thoracoscopic surgery was performed. Based on histological morphology and immunohistochemical examination, this case was considered an intrapulmonary solitary fibrous tumor with malignancy potential, requiring cautious follow-up observation.

Traumatic tumor hemorrhage of inflammatory myofibroblastic tumor of the lung.

A 23-year-old female with a history of idiopathic epilepsy was found to have a right chest cavity shadow in a school health checkup 5 years before. CT revealed a thin-walled cavity lesion in the right middle lobe containing a ball-like mass, showing air crescent sign. After falling due to a seizure, she was transported by ambulance and admitted. CT revealed diffuse ground-glass opacities throughout the right lung field. Bronchoscopy revealed bloody bronchial alveolar lavage fluid. Due to the tumor hemorrhage, an elective simple right middle lobe resection was performed without complications. The initial immunohistochemical staining was negative for ALK using ALK1 clone; however, subsequent staining of ALK by D5F3 and 5A4 clone was positive. Immunostaining findings led to a diagnosis of inflammatory myofibroblastic tumor. The patient remains under regular observation and has experienced no recurrence over the 6-year postoperative period. This case contains two different points: the first is that a cavity lesion of inflammatory myofibroblastic tumor may cause traumatic bleeding and should be treated with caution; the second is that attention should be paid to differences in stainability among clones when diagnosing inflammatory myofibroblastic tumor.

Intrapleural findings of pulmonary light-chain deposition disease.

Light-chain deposition disease is accompanied not only by characteristic CT findings but also by characteristic gross findings of the visceral pleura. Medical thoracoscopy could diagnose LCDD by the findings of the thoracic cavity.

Thyroid transcription factor-1 expression in rectal adenocarcinoma metastatic to the lung.

Distinguishing metastatic lung tumors from primary lung cancer is essential for planning the appropriate treatment strategy. Thyroid transcription factor-1 (TTF-1) is a reliable immunohistochemistry (IHC) marker for differentiating between primary lung adenocarcinomas and metastatic lung tumors originating from colorectal adenocarcinomas. Herein, we report a rare case of TTF-1 expression in both the metastatic lung tumor and primary rectal adenocarcinoma. Aside from the similar histological characteristics of both tumors when stained with hematoxylin-eosin, the IHC patterns, including negative results for alveolar epithelium markers (napsin A and CK7) and positive results for intestinal markers (CK20, CDX2, SATB2, and ß-catenin), of the lung tumor and the primary rectal adenocarcinoma strongly supported the final diagnosis. Considering the non-negligible frequency of TTF-1 positivity in colorectal adenocarcinomas, applying the IHC panel including multiple markers for alveolar epithelium and intestinal differentiation, would be helpful to support the diagnosis of metastatic lung tumor from a rectal adenocarcinoma.

Left upper lobectomy with combined distal aortic arch and left subclavian artery resection after neoadjuvant chemoradiotherapy for locally advanced lung squamous cell carcinoma.

T4 locally advanced non-small cell lung cancer (NSCLC) is a heterogeneous group with a great variety of involved organs and is associated with a poor prognosis. However, appropriately selected patients benefit from surgical resection. The surgical indication must be carefully considered based on the risk-benefit between high surgical stress and expected prognosis, particularly in cases with probable aortic involvement. Here, we report a long-term survival case of left upper lobe squamous cell carcinoma, in which lobectomy and combined distal aortic arch and left subclavian artery resection achieved a complete resection after induction chemoradiotherapy (CRT). Appropriate patient selection considering expected prognosis, induction CRT and complete resection under well-planned cardiopulmonary bypass are essential to achieve a long-term survival on T4 NSCLC with a probable aortic involvement.