A Case Report of False Positive FDG- PET/CT Mediastinal Lymph Node in Oesophageal Adenocarcinoma Revealed to be an Anthracotic and Anthracosilicotic Spindle Cell Pseudotumor (AASCP)

Abstract

Anthracotic and anthracosilicotic spindle cell proliferation (AASCP) is a rare reactive proliferative entity of phagocytic histiocytes which can affect hilar and mediastinal lymph nodes. Fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used for the clinical diagnosis and staging of oesophageal adenocarcinoma. We report the first case of AASCP exhibiting false positivity on FDG-PET imaging. A 76-year-old man with distal esophageal adenocarcinoma underwent PET/CT for staging revealing a positive mediastinal lymph node involvement. The patient underwent Endobronchial Ultrasound Fine Needle Aspiration Biopsy (EBUS-FNA) followed by an oesophagectomy with lymph node dissection. The histological diagnosis of the mediastinal lymphadenopathy was AASCP. In mediastinal lymph nodes of esophageal adenocarcinoma, AASCP could be a cause of false-positivity on FDG-PET imaging.