Case History
The patient is a 57-year-old male with a history of squamous cell carcinoma of the tonsil now presenting with a left neck mass.
What is the diagnosis?
- Squamous cell carcinoma
- Acinic cell carcinoma
- PTC
- Basal cell adenoma
Answer: B. Papillary thyroid carcinoma
Discussion:
PTC is the most common thyroid malignancy in the United States. It can happen at any age with a female to male ratio of 3:1. The smear are usually cellular with sheets of follicular cells exhibiting nuclear overlapping and/or molding. The cytoplasm can be scant or abundant [squamoid, oncocytic (Picture #2) or vacuolated]. Intranuclear pseudoinclusions (black arrow) are specific to PTC and represent cytoplasmic invaginations. Other non-specific nuclear features include grooves (blue arrow) and nucleoli. Another highly specific feature is the presence of papillae with fibrovascular cores (Picture #3).