Abstract:

Objective

To analyze a case of pulmonary sarcomatoid carcinoma （PSC） presented as spontaneous pneumothorax （SP） in our hospital and review the literature，and enhance clinical awareness to reduce the rates of missed diagnosis and misdiagnosis.

Methods

A retrospective analysis was conducted on the clinical data of a patient with PSC who presented with SP as the initial manifestation at our hospital on August 26，2022，and it was explored that the clinical manifestations，pathological characteristics，diagnostic points and treatment strategies of PSC，and relevant literature was analyzed.

Results

A 74-year-old male presented with SP. Preoperative chest CT showed right pneumothorax and right lung compression of about 30%；Soft tissue nodular shadow in the upper lobe of the right lung，about 2.0 cm×1.8 cm in size，and another thick-walled cavity shadow was seen around the lesion. Right upper lobectomy and systematic lymph node dissection were performed with single port thoracoscopic surgery. Postoperative pathological examination：PSC. TNM stage was pT1bN0M0 IA2. The whole gene detection results based on second-generation sequencing：microsatellite stability （MSS） and tumor mutation burden low （TMB-L）. Targeted drug use related mutation results：TP53 splice region mutation，NF1 nonsense mutation，NF1 missense mutation，ATR missense mutation，ALK missense mutation，SDHA missense mutation，KMT2C missense mutation. The patient died after 2 months of follow-up with progressive disease.

Conclusion

PSC progresses rapidly and has a poor prognosis. PSC with SP as the first manifestation is extremely rare. The combination of SP may be one of the risk factors for poor prognosis of PSC.

Key words: Pulmonary sarcomatoid carcinoma, Spontaneous pneumothorax, Second-generation sequencing, Full genetic testing