Endocrine Pathology,Case 2

The patient is a 42-year-old female who noticed a painless lump in her neck about a month ago. It has not seemed to increase or decrease in size.

A painless 3cm mass is palpated in the left neck. The mass moves when the patient swallows and seems contiguous with the thyroid gland. The remainder of the thyroid gland is normal.

Identify the organDescribe the gross findingsWhat is the most probable diagnosis?

Thyroid AdenomaThe surgical specimen consists of a lobe of the thyroid gland containing an adenoma. The adenoma is round, light brown, and sharply demarcated from the deep red thyroid tissue.

Describe the histologic changes

Thyroid AdenomaA microscopic section of thyroid gland reveals a follicular adenoma. The neoplasm is composed of small follicles and is surrounded in part by a thin fibrous capsule. The expanding neoplasm compresses the adjacent normal thyroid.

A – adenoma

B – normal thyroid

C - capsule

How does one differentiate follicular carcinoma from follicular adenoma?

Follicular carinoma shows

A. evidence of capsular or blood vessel invasion

or

B. documented metastases

Thyroid: Follicular carcinomaA microscopic section of thyroid gland reveals a carcinoma composed of well differentiated follicles.

Thyroid: Follicular carcinomaThe microscopic section of thyroid gland reveals a follicular carcinoma. The neoplasm is composed of follicles and invades the lumen of a blood vessel. The wall of the vessel is highlighted by a special stain for elastic fibers (black).

A – blood vessel wall

B - carcinoma