Differential Diagnosis for Rapid Neck Enlargement and Difficulty Swallowing

Single Most Likely Diagnosis

• Multiple Endocrine Neoplasia Type 2B (MEN 2B): This diagnosis is highly suggested due to the combination of a family history of thyroid cancer, rapid neck enlargement, difficulty swallowing, an enlarged thyroid nodule, and the presence of multiple facial neuromas. MEN 2B is characterized by medullary thyroid carcinoma, pheochromocytoma, and distinct physical features including mucosal neuromas.

Other Likely Diagnoses

• Medullary Thyroid Carcinoma (MTC): Given the family history of thyroid cancer and the presence of an enlarged thyroid nodule, MTC is a strong consideration. It can occur sporadically or as part of MEN syndromes.
• Papillary Thyroid Carcinoma: Although less likely than MTC given the specific constellation of symptoms and family history, papillary thyroid carcinoma is a common form of thyroid cancer and could present with a rapidly enlarging neck mass.
• Thyroid Lymphoma: This is a less common malignancy of the thyroid gland but could explain rapid thyroid enlargement and difficulty swallowing, especially in the context of a pre-existing goiter or Hashimoto's thyroiditis.

Do Not Miss Diagnoses

• Anaplastic Thyroid Cancer: Although rare, this aggressive form of thyroid cancer can present with rapid neck enlargement and difficulty swallowing. It is crucial to consider due to its poor prognosis and the need for urgent treatment.
• Metastatic Disease to the Thyroid: Metastases to the thyroid from other primary cancers (e.g., breast, lung, kidney) can cause rapid thyroid enlargement. Given the patient's age and presentation, this might be less likely, but it's a diagnosis that could have significant implications for treatment and prognosis.

Rare Diagnoses

• Familial Adenomatous Polyposis (FAP) with Thyroid Carcinoma: FAP is associated with an increased risk of thyroid cancer, particularly papillary thyroid carcinoma. While the presence of facial neuromas is not typical for FAP, the combination of a family history of cancer and thyroid findings might warrant consideration of this diagnosis.
• Cowden Syndrome: This rare genetic disorder can increase the risk of thyroid diseases, including goiter and thyroid cancer, and is characterized by multiple hamartomas. However, the specific symptoms and signs presented do not strongly suggest Cowden syndrome as a primary diagnosis.