Benign Intrapulmonary Schwannoma: Aspect on F-18 Fluorodeoxyglucose PET/CT

Benign Intrapulmonary Schwannoma With High Uptake on Fluorodeoxyglucose-18 (FDG-18 PET) Presenting as a Pancoast Tumor

A 46-year-old female patient was diagnosed with a rare and benign intrapulmonary schwannoma, a neurogenic tumor that represents approximately 20% of adult mediastinal tumors, with schwannomas being the most common subtype. The patient was initially asymptomatic; however, after a period of four years, the patient presented with bilateral extremity edema, chronic venous stasis, elevated right ventricular systolic pressure, and a slightly enlarged inferior vena cava. These symptoms were caused by the lung tumor compressing intrathoracic structures. This case highlights the need for early evaluation and proper management of neurogenic tumors to avoid serious symptoms and complications. It also emphasizes the importance of vigilant monitoring and prompt surgery to achieve the best outcome for patients with neurogenic tumors.

A Rare Case of Primary Intrapulmonary Neurilemmoma Diagnosed in a 43-Year-Old Asymptomatic Man with a Well-defined Intrapulmonary Mass

Neurilemmoma (NL), also termed schwannoma, presents as a well-circumscribed and encapsulated mass in the human body and is almost always solitary. CT scan of a patient with NL shows a round, ovoid, or lobulated well-demarcated solid mass of soft tissue density. Primary intrathoracic neurogenic tumors location varies. However, the development of such tumors is by far more common in the costovertebral angle of the posterior mediastinum. Here, we report a rare case of a 43-year-old patient, never smoker and previously healthy, who presented with a mass adjacent to the right pulmonary hilum. This was an incidental finding on a chest X-ray after annual checkup at his workplace. The diagnosis was primary intrapulmonary NL. Primary intrapulmonary NL is an extremely rare tumor. However, based on the above, chest CT findings of a well-defined solid mass in an asymptomatic patient should raise the suspicion of NL, irrespective of the tumor localization.

Intrathoracic peripheral nerve sheath tumors-a clinicopathological study of 75 cases

Although peripheral nerve sheath tumors (PNSTs) are common in the posterior mediastinum, they are rare in other mediastinal compartments and in the pleuropulmonary parenchyma. We sought to characterize the clinicopathological features of PNSTs occurring in the lung, pleura, and mediastinum. Diagnoses were confirmed by slide review. Study cases include 21 benign pleuropulmonary PNSTs, 49 benign mediastinal PNSTs, and 5 malignant PNSTs. Benign pleuropulmonary tumors comprised 13 schwannomas, 6 neurofibromas, 1 perineurioma, and 1 ganglioneuroma. Six lesions were endobronchial (3 neurofibromas, 1 schwannoma, 1 perineurioma, 1 ganglioneuroma), whereas the remaining schwannomas and neurofibromas formed parenchymal masses (usually pleural based). Benign mediastinal PNSTs (46 posterior, 2 middle, and 1 anterior) were all schwannomas and showed a female predominance. None of the patients with benign PNSTs experienced recurrence. Of the 5 malignant PNSTs, 4 were pleuropulmonary (3 pleural based) and 1 occurred in the anterior mediastinum. Two of the 5 patients had a history of neurofibromatosis type 1 (aged 27 and 45 years). At last follow-up, 3 of the 5 patients had died of disease, 1 was alive with disease, and 1 was alive with no evidence of disease (41 months). Although rare, a wide histologic range of PNSTs occur in the lung. Although neurofibroma, perineurioma, and ganglioneuroma were observed as endobronchial lesions, most pulmonary schwannomas were pleural-based masses. Mediastinal PNSTs are dominated by posterior mediastinal schwannomas, although schwannomas rarely occur in the other mediastinal compartments as well. Malignant PNSTs are very rare in the thorax, where they show aggressive behavior.