Review Question - QID 100384

The histological sample shows a psammoma body. Psammoma bodies are dystrophically calcified cancer cells seen in papillary thyroid cancer.

Psamomma bodies are a common feature of papillary carcinoma and are also seen in ovarian dysgerminomas and meningiomas. Papillary carcinoma has a papillary architecture with stalks lined by cuboidal epithelium. Other histological features include ground glass nuclei and nuclear grooves. Papillary carcinomas account for 75-90% of thyroid cancers. Prognosis is excellent.

Welker and Orlov discuss the clinical assessment of thyroid nodules. Most thyroid nodules are asymptomatic. About 5 percent of all palpable nodules are malignant. Work-up of nodules begins with thyroid function studies, followed by fine-needle aspiration in euthyroid patients.

Bai et al. reviewed the impact of pathological features on survival in 229 patients with papillary carcinoma. Psammoma bodies were significantly correlated with gross lymph node metastasis and advanced stage grouping. The presence of psamomma bodies indicated poorer disease-free survival.

Figure A shows a psammoma body in a tissue sample of papillary thyroid carcinoma.

Incorrect answers:
Answer 1: Lymphomas are typically solid tumors of lymphatic cells. Thyroid lymphoma is associated with Hashimoto’s thyroiditis.
Answer 2: Uniform follicles are characteristic of follicular carcinoma.
Answer 3: Medullary carcinoma originates from parafollicular C cells that produce calcitonin. Histologically, amyloid deposition is a prominent characteristic of medullary carcinoma.
Answer 5: Undifferentiated thyroid cancer is rare. It occurs in older patients and is often unresponsive to treatment.