PATH - Hypothyroidism

Question 1

Hashimoto thyroiditis

Answer 1

Most common cause of hypothyroidism in iodine-sufficient regions;

an autoimmune disorder:
*antithyroid peroxidase and *antithyroglobulin antibodies

Associated with HLA-DR5.

HISTO
*Hürthle cells, lymphoid aggregates with germinal centers

SX
moderately enlarged, *nontender thyroid.

INC risk of non-Hodgkin lymphoma (typically of B-cell origin).

Question 2

Congenital hypothyroidism (cretinism)

Answer 2

Severe fetal hypothyroidism due to maternal hypothyroidism, thyroid agenesis, thyroid dysgenesis
(most common cause in US), iodine deficiency, dyshormonogenetic goiter.

SX
The 6 P's:
Pot-bellied
Pale
Puffy-faced child
Protruding umbilicus, Protuberant tongue
Poor brain development

Question 3

Subacute granulomatous thyroiditis (de Quervain)

Answer 3

Self-limited disease often following a flu-like illness

HISTO
granulomatous inflammation

SX
INC ESR
jaw pain, very *tender thyroid. (de Quervain is associated with pain.)

May be hyperthyroid early in course, followed by hypothyroidism

Question 4

Riedel thyroiditis

Answer 4

Thyroid replaced by fibrous tissue with inflammatory infiltrate

Considered a manifestation of IgG4-related systemic disease

SX
fixed, hard (rock-like), painless goiter