Solitary Thyroid Nodule

CLINICAL DIAGNOSIS MANUAL

A solitary thyroid nodule is a palpable mass in the thyroid gland that presents without other evident nodules on physical examination or imaging. These nodules can be either benign or malignant, and their discovery may cause concern for both the patient and the physician.

The evaluation of a solitary thyroid nodule involves a series of studies to determine its aetiology, assess its functionality, and rule out malignancy. Solitary thyroid nodules may be associated with various pathologies, each with specific clinical and diagnostic characteristics.

Pathology	Symptoms and Clinical Signs	Diagnosis of Suspicion	Diagnosis of Confirmation
Toxic Autonomous Thyroid Nodule	Weight loss, nervousness, palpitations, heat intolerance. Palpable nodule in the thyroid gland, tachycardia, warm and moist skin, possible signs of hyperthyroidism.	Clinical history and physical examination. Thyroid function tests (TSH, T3, T4): Suppressed TSH, elevated T3 and T4.	Thyroid scan: Increased focal uptake in the nodule (“hot” nodule). Thyroid ultrasound: Nodule characteristics and vascularisation assessment.
Thyroid Carcinoma	Neck mass that may grow rapidly, dysphagia, hoarseness, neck pain in advanced cases. Hard and fixed thyroid nodule, cervical lymphadenopathy, possible vocal cord paralysis.	Clinical history and physical examination. Thyroid ultrasound: Features suggestive of malignancy (hypoechoic, irregular margins, microcalcifications).	Fine needle aspiration biopsy (FNA): Cytology to assess malignancy. CT/MRI: Evaluation of local extension and metastasis.
Thyroid Adenoma	Generally asymptomatic, may have a feeling of pressure in the neck. Palpable nodule in the thyroid gland, mobile and well-defined, generally painless.	Clinical history and physical examination. Thyroid ultrasound: Well-defined, homogeneous nodule.	FNA: Confirmation of benign nature. Thyroid scan: Normal or focal uptake if toxic.
Thyroid Cyst	Feeling of a mass in the neck, occasional pain if associated with haemorrhage within the cyst. Palpable thyroid nodule, soft and fluctuant, possible rapid growth in case of haemorrhage.	Clinical history and physical examination. Thyroid ultrasound: Anechoic mass with thin walls and fluid content.	FNA: Aspiration of content for cytological analysis. Ultrasound follow-up: To assess changes in size or characteristics.