Table 6.7-2. Differential diagnosis of autoimmune and nonautoimmune hyperthyroidism


Graves disease

Nonautoimmune hyperthyroidism (toxic MNG, solitary autonomously functioning nodule)


Recurrent hyperthyroidism; family history of autoimmune thyroid disease or other autoimmune diseases

Previous nontoxic MNG

Signs and symptoms of thyrotoxicosis

No differential features


Features of vascular goiterb

MNG or solitary nodule

Ocular signs and symptoms

Features of orbitopathy (immunologic inflammation), overt orbitopathy in 20%-30% of patients, severe form of progressive ophthalmopathy with infiltrates and edema in 2%-3% of patients

Ocular signs and symptoms of sympathetic hyperactivity (lid lag and stare) do not preclude the diagnosis

Pretibial myxedema

1%-3% of patients


Laboratory thyroid function tests

↓ TSH and ↑ FT4 (less commonly ↑ FT3), no differential features


95% of patients


↑ Anti-TPOc

70% of patients

15% of patients (elderly)

Thyroid Doppler ultrasonography

Diffuse vascularity of thyroid parenchymab


Thyroid radionuclide scintigraphy

High uptake and homogeneous concentration of tracer

Autonomously functioning (hot) nodules and nonfunctioning (cold) areas

a Lack of goiter is not a differential feature.

b Nodules may be present in one-fourth of patients.

c Usually not indicated as not helpful in clarifying etiology (may also be present in healthy individuals and patients with nonautoimmune thyroid diseases).

↑, increased level; ↓, decreased level; anti-TPO, anti-thyroperoxidase; FT3, free triiodothyronine; FT4, free thyroxine; MNG, multinodular goiter; TRAb, thyroid-stimulating hormone receptor antibodies; TSH, thyroid-stimulating hormone.