COMSAE PHASE 1 ENDOCRINE PATHOLOGY
PRACTICE EXAM WITH QUESTIONS AND
VERIFIED ANSWERS, PLUS DETAILED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
Question 1
A 34-year-old woman presents with weight loss despite increased
appetite, heat intolerance, tremulousness, anxiety, and palpitations.
Examination reveals a diffusely enlarged thyroid and bilateral
prominence of the eyes. Laboratory studies show a suppressed TSH and
markedly elevated free T4. Which pathologic process most directly
accounts for the thyroid enlargement?
A. Destruction of thyroid follicles by cytotoxic T cells
B. Autonomous proliferation of parafollicular cells
C. TSH-receptor stimulation by an IgG autoantibody
D. Iodine-induced inhibition of thyroid hormone synthesis
E. Activating mutation of the TSH gene
Answer: C. TSH-receptor stimulation by an IgG autoantibody
Rationale: Graves disease results from IgG autoantibodies that bind
and stimulate the TSH receptor on thyroid follicular cells. This
produces diffuse follicular hyperplasia and increased synthesis and
secretion of T3 and T4. The same autoimmune process can produce
extrathyroidal manifestations such as ophthalmopathy.
Question 2
A 46-year-old woman has fatigue, weight gain, constipation, and cold
intolerance. Her thyroid is firm and diffusely enlarged. Laboratory
1
,studies show elevated TSH and low free T4. A thyroid biopsy
demonstrates dense lymphocytic infiltration, germinal centers, and
destruction of thyroid follicles with extensive Hurthle cell metaplasia.
Which diagnosis is most likely?
A. Graves disease
B. Hashimoto thyroiditis
C. Subacute granulomatous thyroiditis
D. Riedel thyroiditis
E. Toxic multinodular goiter
Answer: B. Hashimoto thyroiditis
Rationale: Hashimoto thyroiditis is an autoimmune destruction of
thyroid tissue characterized histologically by lymphocytic infiltration,
germinal centers, follicular destruction, and Hurthle cell change. It
commonly produces hypothyroidism with elevated TSH and decreased
thyroid hormone levels.
Question 3
A 39-year-old woman develops severe anterior neck pain following an
upper respiratory infection. She has fever, tenderness over the thyroid,
and transient thyrotoxicosis. Biopsy reveals granulomatous
inflammation containing multinucleated giant cells surrounding
fragments of colloid. Which diagnosis is most likely?
A. Hashimoto thyroiditis
B. Graves disease
C. Subacute granulomatous thyroiditis
D. Riedel thyroiditis
E. Acute suppurative thyroiditis
Answer: C. Subacute granulomatous thyroiditis
2
,Rationale: Subacute granulomatous, or de Quervain, thyroiditis often
follows a viral respiratory infection and causes painful thyroid
enlargement. Follicular destruction releases preformed thyroid
hormone, producing a transient thyrotoxic phase. Histology shows
granulomas and multinucleated giant cells surrounding colloid.
Question 4
A patient with chronic autoimmune thyroid disease has thyroid
enlargement followed years later by progressive hypothyroidism. Which
antibody is most strongly associated with the underlying pathology?
A. Anti-thyroid peroxidase antibody
B. Anti-insulin receptor antibody
C. Anti-acetylcholine receptor antibody
D. Anti-mitochondrial antibody
E. Anti-21-hydroxylase antibody
Answer: A. Anti-thyroid peroxidase antibody
Rationale: Anti-thyroid peroxidase antibodies are highly characteristic
of Hashimoto thyroiditis and participate in autoimmune thyroid
destruction. Antithyroglobulin antibodies may also be present. The
resulting follicular destruction ultimately causes hypothyroidism.
Question 5
A 52-year-old man presents with a slowly enlarging thyroid nodule.
Fine-needle aspiration demonstrates cells with clear nuclei containing
nuclear grooves and intranuclear cytoplasmic inclusions. Psammoma
bodies are also identified. Which thyroid malignancy is most likely?
A. Follicular carcinoma
B. Medullary carcinoma
3
, C. Anaplastic carcinoma
D. Papillary thyroid carcinoma
E. Thyroid lymphoma
Answer: D. Papillary thyroid carcinoma
Rationale: Papillary thyroid carcinoma is characterized by nuclear
clearing, nuclear grooves, and intranuclear cytoplasmic inclusions.
Psammoma bodies may also occur. It typically spreads through
lymphatics to cervical lymph nodes and generally has an excellent
prognosis, especially in younger patients.
Question 6
A thyroid mass demonstrates a follicular growth pattern and invasion
through the thyroid capsule and into blood vessels. Which diagnosis is
most appropriate?
A. Follicular adenoma
B. Follicular carcinoma
C. Papillary carcinoma
D. Medullary carcinoma
E. Hurthle cell thyroiditis
Answer: B. Follicular carcinoma
Rationale: Follicular carcinoma cannot reliably be diagnosed by
cytologic appearance alone. The defining pathologic features are
capsular and/or vascular invasion. Follicular carcinoma tends to
spread hematogenously, particularly to bone and lungs, unlike
papillary carcinoma, which commonly spreads through lymphatics.
Question 7
4
PRACTICE EXAM WITH QUESTIONS AND
VERIFIED ANSWERS, PLUS DETAILED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
Question 1
A 34-year-old woman presents with weight loss despite increased
appetite, heat intolerance, tremulousness, anxiety, and palpitations.
Examination reveals a diffusely enlarged thyroid and bilateral
prominence of the eyes. Laboratory studies show a suppressed TSH and
markedly elevated free T4. Which pathologic process most directly
accounts for the thyroid enlargement?
A. Destruction of thyroid follicles by cytotoxic T cells
B. Autonomous proliferation of parafollicular cells
C. TSH-receptor stimulation by an IgG autoantibody
D. Iodine-induced inhibition of thyroid hormone synthesis
E. Activating mutation of the TSH gene
Answer: C. TSH-receptor stimulation by an IgG autoantibody
Rationale: Graves disease results from IgG autoantibodies that bind
and stimulate the TSH receptor on thyroid follicular cells. This
produces diffuse follicular hyperplasia and increased synthesis and
secretion of T3 and T4. The same autoimmune process can produce
extrathyroidal manifestations such as ophthalmopathy.
Question 2
A 46-year-old woman has fatigue, weight gain, constipation, and cold
intolerance. Her thyroid is firm and diffusely enlarged. Laboratory
1
,studies show elevated TSH and low free T4. A thyroid biopsy
demonstrates dense lymphocytic infiltration, germinal centers, and
destruction of thyroid follicles with extensive Hurthle cell metaplasia.
Which diagnosis is most likely?
A. Graves disease
B. Hashimoto thyroiditis
C. Subacute granulomatous thyroiditis
D. Riedel thyroiditis
E. Toxic multinodular goiter
Answer: B. Hashimoto thyroiditis
Rationale: Hashimoto thyroiditis is an autoimmune destruction of
thyroid tissue characterized histologically by lymphocytic infiltration,
germinal centers, follicular destruction, and Hurthle cell change. It
commonly produces hypothyroidism with elevated TSH and decreased
thyroid hormone levels.
Question 3
A 39-year-old woman develops severe anterior neck pain following an
upper respiratory infection. She has fever, tenderness over the thyroid,
and transient thyrotoxicosis. Biopsy reveals granulomatous
inflammation containing multinucleated giant cells surrounding
fragments of colloid. Which diagnosis is most likely?
A. Hashimoto thyroiditis
B. Graves disease
C. Subacute granulomatous thyroiditis
D. Riedel thyroiditis
E. Acute suppurative thyroiditis
Answer: C. Subacute granulomatous thyroiditis
2
,Rationale: Subacute granulomatous, or de Quervain, thyroiditis often
follows a viral respiratory infection and causes painful thyroid
enlargement. Follicular destruction releases preformed thyroid
hormone, producing a transient thyrotoxic phase. Histology shows
granulomas and multinucleated giant cells surrounding colloid.
Question 4
A patient with chronic autoimmune thyroid disease has thyroid
enlargement followed years later by progressive hypothyroidism. Which
antibody is most strongly associated with the underlying pathology?
A. Anti-thyroid peroxidase antibody
B. Anti-insulin receptor antibody
C. Anti-acetylcholine receptor antibody
D. Anti-mitochondrial antibody
E. Anti-21-hydroxylase antibody
Answer: A. Anti-thyroid peroxidase antibody
Rationale: Anti-thyroid peroxidase antibodies are highly characteristic
of Hashimoto thyroiditis and participate in autoimmune thyroid
destruction. Antithyroglobulin antibodies may also be present. The
resulting follicular destruction ultimately causes hypothyroidism.
Question 5
A 52-year-old man presents with a slowly enlarging thyroid nodule.
Fine-needle aspiration demonstrates cells with clear nuclei containing
nuclear grooves and intranuclear cytoplasmic inclusions. Psammoma
bodies are also identified. Which thyroid malignancy is most likely?
A. Follicular carcinoma
B. Medullary carcinoma
3
, C. Anaplastic carcinoma
D. Papillary thyroid carcinoma
E. Thyroid lymphoma
Answer: D. Papillary thyroid carcinoma
Rationale: Papillary thyroid carcinoma is characterized by nuclear
clearing, nuclear grooves, and intranuclear cytoplasmic inclusions.
Psammoma bodies may also occur. It typically spreads through
lymphatics to cervical lymph nodes and generally has an excellent
prognosis, especially in younger patients.
Question 6
A thyroid mass demonstrates a follicular growth pattern and invasion
through the thyroid capsule and into blood vessels. Which diagnosis is
most appropriate?
A. Follicular adenoma
B. Follicular carcinoma
C. Papillary carcinoma
D. Medullary carcinoma
E. Hurthle cell thyroiditis
Answer: B. Follicular carcinoma
Rationale: Follicular carcinoma cannot reliably be diagnosed by
cytologic appearance alone. The defining pathologic features are
capsular and/or vascular invasion. Follicular carcinoma tends to
spread hematogenously, particularly to bone and lungs, unlike
papillary carcinoma, which commonly spreads through lymphatics.
Question 7
4
