Endobronchial ultrasound-guided Transbronchial needle aspiration (EBUS-TBNA) in simulator lesions of pulmonary pathology: a case report of pulmonary Myospherulosis.

Background: Myospherulosis develops as the result of a reaction between exogenous lipids and red blood cells (RBC) of the patient, being the latter injured when perceived as a foreign body by the immune system, triggering an intense inflammatory response.

Case Presentation: A 63-year-old man with a history of dyslipidemia, Barret's esophagus, and coronary disease, who was taken to thoracoscopy and left inferior lobectomy due to the presence of a pulmonary mass. A primary pulmonary adenocarcinoma was diagnosed. On follow up a PET-CT was performed, in which a metabolically active lesion was described adjacent to the prior lobectomy, suggesting a local relapse. EBUS-TBNA was then performed, obtaining a sample from which histopathological pattern compatible with myospherulosis was obtained.

Conclusions: Although it is a rare entity, myospherulosis has a well-defined morphological pattern. By not recognizing myospherulosis as a benign lesion, a patient's risk of invasive cancer can be overestimated. It is a phenomenon found with increasing frequency and has been reported in different tissues, however, this is the first report in the literature of myospherulosis of the lung. Greater awareness is required regarding the existence of this phenomenon.