We do not have any affiliations or financial interests in any of the corporate organizations involved with the products to which our case study will refer.
Continuing Medical Education (CME): The American Society of Cytopathology is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.
The American Society of Cytopathology designates this enduring educational activity for a maximum of 1 AMA PRA Category 1 credit(s).TM Physicians should only claim credit commensurate with the extent of their participation in the activity.
American Board of Pathology Maintenance of Certification (MOC): This product can help fulfill the CME requirements and Self-Assessment Modules (SAMs) mandated by the American Board of Pathology MOC process.
Continuing Medical Laboratory Education (CMLE): The ASC designates this activity for the indicated number of CMLE credit hours and also fulfills requirements of the ABMS to participate in the Maintenance of Certification program.
This program is approved for continuing education credits in the State of Florida for 1 credit and the State of California for ½ credit.
Review the Case Study and visit the ASC Web site (https://education.cytopathology.org/) to take the test for Continuing Education Credit.
A 62-year-old man presented to our thyroid clinic with thyroiditis and a multinodular goiter. He had known renal cell carcinoma. A chest computed tomographic (CT) scan was performed to rule out metastatic disease and revealed a 1.8 cm thyroid nodule (Figure 1A). TSH and free thyroxine (T4) were within the normal ranges. Ultrasound of the thyroid revealed nodules in the right isthmus and right lower lobe that were well-circumscribed, hypoechoic, and solid nodules. Both were greater than 1.0 cm in diameter (Figure 1B). An ultrasound-guided FNA was performed.
The direct smears were cellular, with many small, loose clusters of epithelial cells with abundant pale to granular cytoplasm with ill-defined borders (Figure 2). The nuclei were relatively round with irregular nuclear borders, abnormal chromatin pattern, and prominent nucleoli (Figure 3). The epithelial clusters were mixed with vascular and stromal components (Figure 4). Metastatic clear cell renal cell carcinoma was diagnosed after comparison to the patient’s right renal tumor (Figure 5), which had been resected 9 months earlier.
Figure 1. (A) Computed tomography (CT) scan of the thyroid demonstrates a 1.8 cm isthmic nodule (arrow). (B) Ultrasound shows solid nodules in the right isthmus (arrowhead) and right midpole of the thyroid gland. The image demonstrates the radiologic features of the nodule.
Figure 2. Thyroid gland FNA, prepared on an ethanol-fixed slide, Papanicolaou stain, 40x: The tumor cells display irregular nuclear borders, abnormal chromatin and prominent nucleoli with granular cytoplasm.
Figure 3. Thyroid gland FNA, prepared on an ethanol-fixed, Papanicolaou stain, 40x: The tumor cells are clinging to vessels, indicating a vascular tumor.
Figure 4. Thyroid gland FNA, prepared on an ethanol-fixed slide, Papanicolaou stain, 60x: The tumor cells show abundant pale, granular cytoplasm with ill-defined borders and round nuclei with macronucleoli.
Figure 5. Section from the patient’s prior right kidney nephrectomy, Hematoxylin & Eosin stain, 40x: Classic clear cell renal cell carcinoma, with solid growth of nested tumor cells with round nuclei, prominent nucleoli, abnormal chromatin, clear cytoplasm and crisp cellular membranes.