Tirzepatide use linked to new diagnosis of mixed medullary and papillary thyroid carcinoma in 68-year-old female.
Background
Medullary thyroid cancer (MTC), a rare neuroendocrine tumor originating from thyroid parafollicular C cells, can be inherited (e.g., familial medullary thyroid cancer (FMTC), multiple endocrine neoplasia type 2 (MEN 2)) or sporadic. GLP-1 receptor agonist (GLP1 RA) drugs, including semaglutide and tirzepatide, carry an FDA black box warning against use in patients with a personal or family history of MTC or MEN2. This warning is based on rodent studies showing thyroid C-cell tumors. However, human studies have not yet confirmed an association between GLP1RAs and differentiated thyroid cancer risk, and there is no consensus on pre-treatment or on-treatment screening for thyroid cancer.
Study Design
This report details a case of a 68-year-old female with type 2 diabetes who was receiving tirzepatide treatment. She presented with a newly identified neck mass. The patient's medical history and current medication regimen, specifically the use of tirzepatide, were noted. Subsequent diagnostic evaluation, including imaging and biopsy, was performed to characterize the nature of the neck mass and establish a definitive diagnosis. The abstract does not specify the duration of tirzepatide treatment or the exact dose administered prior to the presentation of the neck mass.
Results
The diagnostic workup of the 68-year-old female patient revealed a complex thyroid malignancy. Pathological examination confirmed a diagnosis of mixed medullary and papillary thyroid carcinoma. This finding is significant given the patient's ongoing treatment with tirzepatide, a GLP-1 receptor agonist. The presence of both medullary and papillary components is notable, as the black box warning for GLP-1RAs specifically pertains to MTC due to C-cell hyperplasia observed in preclinical rodent models. The abstract does not provide specific tumor size, staging information, or details on the patient's calcitonin levels, which are typically elevated in MTC. This case represents a clinical observation that aligns with the theoretical concern outlined in the FDA warning.
The patient was newly diagnosed with mixed medullary and papillary thyroid carcinoma while on tirzepatide for type 2 diabetes.
Key Findings
- A 68-year-old female on tirzepatide for type 2 diabetes presented with a neck mass.
- Diagnosis confirmed mixed medullary and papillary thyroid carcinoma.
- The case highlights the relevance of the FDA black box warning for GLP-1RAs regarding MTC risk.
Why It Matters
This case report underscores the clinical relevance of the FDA black box warning for GLP-1 receptor agonists like tirzepatide regarding medullary thyroid cancer (MTC) risk. While a single case cannot establish causality, it highlights the importance of thorough patient screening for personal and family history of MTC or MEN2 before initiating GLP-1 RA therapy. Clinicians should maintain a high index of suspicion for thyroid nodules or masses in patients on these medications, especially given the lack of consensus on routine screening. This report may prompt further discussion on whether specific monitoring protocols, such as baseline and periodic calcitonin measurements or thyroid ultrasounds, should be considered for patients receiving GLP-1RAs, particularly those with pre-existing risk factors or new symptoms like a neck mass. It reinforces the need for ongoing vigilance and patient education regarding potential thyroid-related adverse events.
tirzepatide
medullary thyroid cancer
papillary thyroid cancer
thyroid carcinoma
type 2 diabetes
glp-1 agonist