N1a

A 49 year old woman presents to the office after her PCP noted a nodule on her thyroid. Although her thyroid was diffusely enlarged last visit - the nodule is new. It is noted in her chart that she was exposed to radiation as a child.  She notes that “it feels like something is stuck in my throat.” She has a dry cough and some difficulty swallowing.

This is from a previous biopsy of the patients thyroid: What does she likely have a history of?

Hashimoto's

gross specimen of Thyroid from a patient with the same Dx as our patient

If you were to palpate her neck what would you expect to feel?

• solitary mass of hard consistancy
• fixed to tissue 
• moves with swallowing
• ill-defined borders - not encapsulated!
• probably < 5 cm

Describe the histologic findings:

• papillary: finger like projections
• note: fibrovascular core with single cell layer
• psammoma bodies
• orphan annie (ground glass) nuclei: finely dispersed chromatin

What is the Dx?

·         Papillary thyroid cancer

What are three ways tumors tend to spread? How about this type in particular?

·         Through the lymphatics, through the blood, direct seeding

·         Papillary throid cancer tends invade lymphatics (less likely invade blood vessels)

Activation of which protooncogene is associated with this type of cancer?

·         RET/PTC gene rearrangement

What in her history puts her at risk for this type of cancer?

•       Most common thyroid tumor post radiation exposure
•            Hashimotos
•      Note: >70% thyroid cancer is papillary in USA- overall thyroid cancer is rare (1.5% adult cancers)