Case of the Month: March 2024
Clinical history
A 35-year-old female patient has an asymptomatic thyroid mass that was diagnosed 6 years ago as a 10 mm “cyst” that was followed by surveillance. It recently became larger in size, to “almost double the size”, and prompted the patient to seek medical care. Thyroid hormone and TSH levels were within normal limits, and there was no cervical lymphadenopathy. The physical examination revealed a palpable neck mass on the left side of the neck, but was otherwise unremarkable. Ultrasound showed a left 2.0 x 1.7 cm mass, TIRADS 4. The patient underwent a fine needle aspiration of the thyroid mass.
Questions:
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How are thyroid cytology specimens reported by pathologists?
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How would you describe the cells in this cytology sample?
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What is your differential diagnosis?
How to participate
Take a look at the images.
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If you are a medical student at the University of Toronto, you can also:
If you do, you are in for a chance to win a $100 gift card! (UofT Med students only).
Discover the answer to March's Case of the Month challenge!
The answer to March’s Case of the Month is medullary thyroid carcinoma!
Medullary thyroid carcinomas are neuroendocrine tumours derived from the C cells (calcitonin producing cells) in the thyroid gland. Most cases are sporadic (70%) and others are due to hereditary syndromes such as MEN2A and MEN 2B, familial medullary thyroid carcinoma, von Hippel-Lindau disease, and neurofibromatosis.
Thyroid cytology specimen reporting is based on the Bethesda System. Reporting categories in this system are: I - Non-diagnostic or inadequate (e.g. if a sample contains only colloid or blood), II - Benign, III - Atypia/follicular lesion of undetermined significance, IV - Follicular neoplasm or suspicious for follicular neoplasm, V - Suspicious for malignancy, and VI – Malignant. Medullary thyroid carcinoma has fairly specific cytomorphology and would fall into category VI – malignant.
If you are a current medical student at U of T, you can register to join the March case of the month lecture online or in person and have a chance to win a $100 gift card!
You can also join the Special Interest Group in Laboratory Medicine to learn more about Laboratory Medicine.
