Endocrine Abstracts

Background: The nature of adrenal tumors can occasionally be difficult to determine using only laboratory and radiological findings. In those rare cases, obtaining a cytological sample by fine needle aspiration (FNA) can be valuable. Transabdominal ultrasound, endoscopic ultrasound (EUS), and computerized tomography (CT) guided biopsy are the most used methods for obtaining a cytological sample from an adrenal lesion.

Methods: Adrenal FNAs performed between the years 2000–2022 at the Karolinska University Hospital were identified using a search function incorporated in our institutional pathology database. Clinical and histological data were retrieved from medical records.

Results: Of 241 adrenal FNAs identified, 113 (46.9%) were obtained by transabdominal ultrasound, 72 (29.9%) were obtained by EUS, 53 (22%) using CT-guided technique, one FNA was obtained during surgery (0.4%) and in two cases (0.8%) the modality was not mentioned in the available medical charts. Preceding imaging indicated suspected malignant lesions in 184 cases (76.3%). Malignancy was confirmed by cytology in 139 cases (57.6%). A new FNA was performed to obtain the correct diagnosis in 10 cases (4.1%). Adequate material for diagnosis was retrieved in 98 cases (86.7%) by transabdominal ultrasound, 69 cases (95.8%) by EUS and in 47 cases (88.7%) by CT-guided biopsies. An endocrinological assessment of adrenal function was performed before cytology in 122 cases (50.6%). Using FNA, adrenal lesions were diagnosed as adrenal metastases in 127 cases (52.7%) and adrenocortical cells (indicative of an adrenal cortical lesion) were found in 92 cases (38.1%). Of the latter ones, 4 (1.7%) received a diagnosis of adrenal cortical carcinoma. The remaining FNAs showed lymphoma in 7 cases (2.9%), tuberculosis and acute myeloid leukemia in one case each (0.4%). The diagnosis was unclear in 13 cases (5.4%). Most metastases were from lung carcinoma (71 cases, 55.9%) followed by malignant melanoma (10 cases, 7.9%), renal cell carcinoma (9 cases, 7.1%), gynecological cancers (7 cases, 5.5%), and other malignancies (30 cases, 23.6%) (e.g., breast, prostate, hepatocellular, and gastrointestinal carcinoma). Complications due to the biopsy procedure, such as bleeding and pneumothorax, were reported in 19 cases (7.5%).

Conclusions: Complication rates for FNA were low and an adequate sample was obtained in most cases regardless of imaging method used. FNA of the adrenal glands is a useful tool for diagnosis of adrenal tumors, especially when a metastasis is suspected.

Keywords: fine needle aspiration, adrenal glands.