The clinical consequences of functional adrenal uptake in the absence of cross-sectional mass on FDG-PET/CT in oncology patients.

PURPOSE: Oncology patients undergoing positron emission tomography/computed tomography (PET/CT) occasionally show discrete adrenal [18F]-fluorodeoxyglucose (FDG) uptake without an associated nodule on CT, leaving the clinician uncertain about the need to proceed with biopsy or surgical referral. This study aimed to identify the prevalence of this radiological finding and to evaluate the effectiveness of FDG uptake values in risk stratification for adrenal metastasis. METHODS: From 2014 to 2015, oncology patients who underwent FDG-PET/CT and demonstrated elevated FDG uptake in the adrenal gland without discrete nodularity on cross-sectional imaging were included in a retrospective cohort analysis. Clinical records and FDG-PET/CT scans were reviewed for clinicopathological data, follow-up data, SUVmax (highest SUV of either adrenal gland), and SUVratio (SUVmax/background liver uptake). A receiver operating characteristic analysis was conducted to evaluate the associations between SUV values and the progression to adrenal metastasis. RESULTS: Of 3040 oncology patients who underwent FDG-PET/CT scans, 92 (3.0%) showed elevated adrenal uptake without associated mass. From the final study cohort of 66 patients with comprehensive follow-up data, 5 patients (7.6%) developed evidence of adrenal metastasis. At SUVmax < 3.25 (AUC = 0.757) and SUVratio < 1.27 (AUC = 0.907), 34.8% and 60.6% of patients could be excluded with 100% negative predictive value, respectively. CONCLUSIONS: Thresholds of SUVmax and SUVratio identified a significant proportion of patients who did not develop adrenal metastasis. In oncology patients who demonstrate increased adrenal FDG uptake without a discrete lesion on FDG-PET/CT, quantitative uptake values may be useful in selecting those not at risk of developing adrenal metastatic disease.

Preoperative Computed Tomography Changes Surgical Management for Clinically Low-Risk Well-Differentiated Thyroid Cancer.

BACKGROUND: In the current guidelines for differentiated thyroid cancer (DTC), computed tomography (CT) of the neck has a limited role. The authors hypothesized that adding CT to the workup of clinically low-risk DTC size 4 cm or smaller changes the surgical management for a portion of patients due to detection of clinically significant lymph node metastases not located by ultrasound of the neck. METHODS: A prospective cohort of DTC patients at an academic referral center between 2012 and 2016 was reviewed. All the patients with fine-needle aspiration cytopathology results suspicious for malignancy or malignant tumor (Bethesda category 5 or 6, respectively) underwent CT before surgery. Clinically low-risk DTC patients were selected if they had a tumor diameter of 4 cm or less and no evidence for local invasion or suspicious lymph nodes seen on ultrasound. Outcomes focused on alteration of the surgical plan based on CT and correlation with pathology. RESULTS: The CT findings for 25 (22.5%) of 111 patients with clinically low-risk DTC led to a change in surgical management. Of these 25 patients, 16 (14.4% of the entire cohort) benefited due to the removal of clinically significant lymph node disease not seen on ultrasound. Categorization of the group that had a change in management showed that 6 (85.7%) of 7 lateral neck dissections and 10 (55.6%) of 18 central neck dissections (CND) harbored metastatic nodes larger than 2 mm. CONCLUSIONS: In the group with clinically low-risk DTC, CT changed surgical management for a substantial number of the patients with clinically significant nodal disease not detected by ultrasound. This highlights the fact that in certain practice settings, adding CT to the preoperative staging may be favorable for the detection of nodal metastasis.

Papillary Thyroid Cancers with Focal Tall Cell Change are as Aggressive as Tall Cell Variants and Should Not be Considered as Low-Risk Disease.

BACKGROUND: The tall cell variant of papillary thyroid carcinoma (PTC) is as an aggressive histological variant. The proportion of tall cells needed to influence prognosis is debated. METHODS: Patients with PTC and tall cells, defined as having a height-to-width ratio of ≥ 3:1, seen at a high-volume center between 2001 and 2015, were reviewed. Specimens were classified as (1) focal tall cell change, containing < 30% of tall cells; (2) tall cell variant, ≥ 30% of tall cells; and (3) control cases selected from infiltrative classical PTCs without adverse cytologic features. Univariate, sensitivity, and multivariate analyses were performed with persistent/recurrent disease as the primary outcome. RESULTS: We identified 96 PTCs with focal tall cell change, 35 with the tall cell variant and 104 control cases. Factors associated with poor clinical prognosis were significantly greater in those with focal tall cell change and tall cell variants. Regarding primary outcome, hazard ratios were 2.3 (95% confidence interval [CI] 1.0-5.7) for focal tall cell change, and 3.4 (95% CI 1.2-8.7) for tall cell variants compared with controls. Five-year disease-free survival was higher for the control group (92.7%, CI 87.4-98.0) compared with focal tall cell change (76.3%, CI 66.1-86.5) and the tall cell variant (62.2%, CI 43.2-81.2). When stratified in groups consisting of tall cell proportions (< 10%, 10-19%, 20-29% and ≥ 30%), identification of ≥ 10% tall cell change was associated with worse outcome (p = 0.002). CONCLUSIONS: PTCs with ≥ 10% tall cell change have worse prognosis than those without tall cells. Our data indicate that thyroid cancer management guidelines should consider PTCs with focal tall cell change outside of the low-risk classification.

Autoinfarction of Giant Parathyroid Adenoma after Preoperative Withdrawal of Anticoagulants.

A 71-year-old man with known history of atrial fibrillation (treated with routine rivaroxaban therapy) was found to have incidental biochemical elevated calcium and parathyroid hormone (PTH) levels. His physical examination demonstrated the presence of a palpable right neck mass. Subsequent imaging studies revealed a large parathyroid mass as well as multiple bone lesions, raising the suspicion of parathyroid carcinoma. The anticoagulant therapy was stopped 5 days prior to his elective surgery. The night before his elective surgery, he presented to the emergency room with profound hypocalcemia. The surgery was postponed and rescheduled after calcium correction. Intraoperative findings and detailed histopathological examination revealed an infarcted 4.0 cm parathyroid adenoma with cystic change. His bony changes were related to brown tumors associated with long-standing hyperparathyroidism. Autoinfarction of a large parathyroid adenoma causing severe hypocalcemia is a rare phenomenon and may be considered in patients with large parathyroid adenomas after withdrawal of anticoagulants.

Clinical Safety of Renaming Encapsulated Follicular Variant of Papillary Thyroid Carcinoma: Is NIFTP Truly Benign?

BACKGROUND: Renaming encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) to noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was recently suggested to prevent the overtreatment, cost and stigma associated with this low-risk entity. The purpose of this study is to document the incidence and further assess the clinical outcomes of reclassifying EFVPTC to NIFTP. METHODS: We searched synoptic pathologic reports from a high-volume academic endocrine surgery hospital from 2004 to 2013. The standard of surgical pathology practice was based on complete submission of malignant thyroid nodules along with the nontumorous thyroid parenchyma. Rigid morphological criteria were used for the diagnosis of noninvasive EFVPTC, currently known as NIFTP. A retrospective chart review was conducted looking for evidence of malignant behavior. RESULTS: One hundred and two patients met the strict inclusion criteria of NIFTP. The incidence of NIFTP in our cohort was 2.1% of papillary thyroid cancer cases during the studied time period. Mean follow-up was 5.7 years (range 0-11). Five patients were identified with nodal metastasis and one patient with distant metastasis. Overall, six patients showed evidence of malignant behavior representing 6% of patients with NIFTP. CONCLUSION: Our study demonstrates that the incidence of NIFTP is significantly lower than previously thought. Furthermore, evidence of malignant behavior was seen in a significant number of NIFTP patients. Although the authors fully support the de-escalation of aggressive treatment for low-risk thyroid cancers, NIFTP behaves as a low-risk thyroid cancer rather than a benign entity and ongoing surveillance is warranted.