OBJECTIVES: This study aims to evaluate the extent of the correlation between positron emission tomography-computed tomography (PET-CT) and histopathological and/or cytological evaluations in demonstrating malignancy and identifying the primary in patients with head and neck tumors of unknown primary. PATIENTS AND METHODS: The excision records and files of 32 patients (24 males and 8 females; mean age 54.2 years; range 24 to 75 years) with previous PET-CT evaluations performed due to a mass with an unknown origin and to identify the primary were retrospectively analyzed. Positron emission tomography-computed tomography results and neck dissection (ND) materials were compared and PET-CT's ability to provide localization of the primer was determined by standardizing the study data. RESULTS: In respect of determining primary localization, PET-CT's sensitivity was determined as 66.6%, its specificity as 33.3%, its positive predictive value as 80%, and its negative predictive value as 20%. When the neck dissection specimens were considered according to the different regions they were obtained from: PET-CT's specificity was determined as 63.6%, its sensitivity as 94.5%, its positive predictive value as 87.5%, and its negative predictive value as 58.1%. CONCLUSION: Positron emission tomography-computed tomography sensitivity in determine the regions with pathologic lymph node involvement according to the BD specimen results and positive predictive value in identifying primary localization was found to be in accordance with the literature. Based on these results, PET-CT is a valuable method for early diagnosis and treatment in difficult cases.
OBJECTIVES: This study aims to evaluate the extent of the correlation between positron emission tomography-computed tomography (PET-CT) and histopathological and/or cytological evaluations in demonstrating malignancy and identifying the primary in patients with head and neck tumors of unknown primary. PATIENTS AND METHODS: The excision records and files of 32 patients (24 males and 8 females; mean age 54.2 years; range 24 to 75 years) with previous PET-CT evaluations performed due to a mass with an unknown origin and to identify the primary were retrospectively analyzed. Positron emission tomography-computed tomography results and neck dissection (ND) materials were compared and PET-CT's ability to provide localization of the primer was determined by standardizing the study data. RESULTS: In respect of determining primary localization, PET-CT's sensitivity was determined as 66.6%, its specificity as 33.3%, its positive predictive value as 80%, and its negative predictive value as 20%. When the neck dissection specimens were considered according to the different regions they were obtained from: PET-CT's specificity was determined as 63.6%, its sensitivity as 94.5%, its positive predictive value as 87.5%, and its negative predictive value as 58.1%. CONCLUSION: Positron emission tomography-computed tomography sensitivity in determine the regions with pathologic lymph node involvement according to the BD specimen results and positive predictive value in identifying primary localization was found to be in accordance with the literature. Based on these results, PET-CT is a valuable method for early diagnosis and treatment in difficult cases.