CASE REPORT Case Report: Sarcoidosis with azygos vein enlargement mimicking metastatic cancer [version 1; peer review: 1 approved, 1 approved with reservations] Abdallah Qasim 1 , Omar Kousa 1 , Mohamed Mansour 2 , Ahmad K. Aly 3 , Dana Awad 1 , Hamza Kousa 4 , Yazan Addasi 1 , Bader Abuhazeem 1 , Venkata Andukuri 1 1 Internal Medicine, Creighton University Medical Center, Omaha, NE, 68154, USA 2 Internal Medicine, Sheikh shakhbout medical city, Abu Dhabi, Abu Dhabi, 11001, United Arab Emirates 3 Department of Radiology, Creighton University Medical Center, Omaha, NE, 68154, USA 4 University of Sharjah, Sharjah, 27272, United Arab Emirates First published: 30 Jun 2020, 9:661 https://doi.org/10.12688/f1000research.24041.1 Latest published: 30 Jun 2020, 9:661 https://doi.org/10.12688/f1000research.24041.1 v1 Abstract Sarcoidosis is a systemic disease with heterogeneous clinical manifestations that is characterized histologically by the presence of noncaseating granulomas in the affected organs. It can be a diagnostic challenge, especially when mimicking malignancy or fungal infections. Previous case reports of sarcoidosis presenting with multiple masses are highly suggestive of infectious or malignant etiology. In this case, our patient presented with enlarged lymph node and was found to have innumerable nodules in the mediastinum, lungs, and liver. Azygos vein enlargement was also seen on radiological imaging, and malignancy was highly suspected; hence, an extensive workup was conducted, including laboratory, radiology and biopsy evaluation, which were diagnostic of sarcoidosis. Our case showed the importance of correlation of the history, physical examination, radiological and histopathologic studies in confirming the diagnosis and the need to rule out other serious infections and malignancies, especially with azygous vein enlargement, which can sometimes be missed in chest radiograph. Keywords Sarcoidosis, Malignancy, Liver mass, Azygous vein Open Peer Review Reviewer Status Invited Reviewers 1 2 version 1 30 Jun 2020 report report Marios Rossides , Karolinska Institutet, Stockholm, Sweden 1. Ichiro Mizushima, Kanazawa University Hospital, Kanazawa, Japan 2. Any reports and responses or comments on the article can be found at the end of the article. Page 1 of 11 F1000Research 2020, 9:661 Last updated: 04 AUG 2021