Current Thoracic Surgery 2018 , Vol 3 , Issue 1
The differential diagnostic role of PET-CT in sarcoidosis and lymphoma
Ahmet Bülent Kargi1,Harun Süslü2,Çağatay Ünsal3,Osman Fatih Boztepe4,Yener Koç3
1Department of Thoracic Surgery, Medicalpark Hospital Antalya, Turkey
2Department of Nuclear Medicine, Medicalpark Hospital Antalya, Turkey
3Department of Hematology and Stem Cell Transplantation Unit, Medicalpark Hospital Antalya, Turkey
4Department of Otolaryngology, Istinye University Health Sciences Faculty, Istanbul, Turkey
DOI : 10.26663/cts.2018.0001 Background: Mediastinal lymphadenopathy (MLAP) is observed in various conditions of malignant or benign diseases. The two common diseases leading to MLAP are mediastinal lymphomas and sarcoidosis. The aim of study is to describe distinctive lymph node involvement patterns with sarcoidosis and lymphoma defined by PET-CT.

Materials and Methods: 82 patients (45 women and 37 men) with a median age of 53.5 (21-88) years who had PET-CT for differential diagnose for MLAP were evaluated retrospectively. 31 (37.8%) patients diagnosed sarcoidosis, and 51 (62.2%) lymphoma that had histologically proven by various surgical procedures.

Results: There were no statistical difference between gender, age and average SUV max of groups (p = 0.068, p = 0.846, p = 0.338). 26 of 31 patient (83.9%) of sarcoidosis group had abnormal findings compared the lymphoma group (51.0%) which showed statistically significant difference (p = 0.003). Meanwhile there were no statistical difference between hilar lymph nodes and liver involvement among the groups (p = 0.239 and p = 0.917), cervical, axillary, abdominal lymph nodes and spleen involvement was significantly higher in the lymphoma group (p = 0.008, p < 0.001, p < 0.001 and p = 0.001). Bone marrow (BM) involvement were also significantly higher in lymphoma group (p < 0.001).

Conclusions: There are no specific MLAP findings to differentiate sarcoidosis from lymphomas by PET-CT. It is more likely that the pathological conclusion will be consistent with lymphoma rather than sarcoidosis, in case of involvement of cervical, abdominal and axillary lymph nodes, spleen and BM involvement; however abnormal pulmonary parenchymal findings are in the favor of the diagnosis of sarcoidosis. Keywords : mediastinal lymphadenopathy, sarcoidosis, lymphoma, PET-CT