NursingCenter Blog

Anaplastic Thyroid Cancer: A Rare but Deadly Diagnosis

Oct 29 2024 by Jennifer Collins, MSN, CRNP, AG-ACNP-BC

Background
Anaplastic thyroid cancer (ATC), also known as undifferentiated thyroid carcinoma, is a highly aggressive and very rare malignant tumor that accounts for 2-3% of all thyroid cancers (Limaiem et al. 2023). ATC is one of the deadliest diseases and carries a poor prognosis with a mortality rate of close to 100%. At the time of diagnosis, in addition to local invasion, patients often present with metastatic spread to lymph nodes and distant sites (Limaiem et al. 2023).

Epidemiology
The incidence of ATC is approximately 1-2 in one million persons and accounts for 0.9-9% of all thyroid cancers across the globe (Tuttle & Sherman, 2024). The median age at diagnosis is 65, with 60-70% of tumors occurring in females (Tuttle & Sherman, 2024).

Clinical Manifestations
Nearly all patients diagnosed with ATC present with a thyroid mass, with the primary presenting symptom being a rapidly enlarging neck mass, which occurs in about 85% of patients (Tuttle & Sherman, 2024). The expanding tumor may cause pain, tenderness, and compression of the upper digestive tract and airway, resulting in dyspnea, dysphagia, cough, and hoarse voice (Tuttle & Sherman, 2024). Less common symptoms include bone pain, headache, confusion, anorexia, weight loss, fatigue, and chest pain from distant metastasis (Tuttle & Sherman, 2024).

Patients with suspected ATC who present with a rapidly growing neck mass and voice hoarseness should undergo emergent evaluation by an otolaryngologist to assess for vocal cord dysfunction, airway compromise, and need/role for surgical resection. Even if the airway appears stable, it is appropriate to consult an otolaryngologist/head and neck surgeon early in the evaluation in case an intervention is required (Tuttle & Sherman, 2024).

Diagnosis
The most common ultrasonographic findings of ATC include solid masses, marked hypo- echogenicity (dark appearance on ultrasound due to density), irregular margins, and involvement of cervical lymph nodes (Limaiem et al. 2023). The diagnosis is made by fine-needle aspiration biopsy, although core biopsy is preferred if it will not delay the initiation of treatment. Molecular testing for the presence of BRAF mutation should be done as quickly as possible after the diagnosis to assess for targetable mutations. Appropriate imaging is critical in determining the extent of the disease, planning therapy, and monitoring response to treatment modalities. If PET/CT scanning is not readily available, CT imaging of the brain, neck, chest, abdominal and pelvis with CT or MRI provides adequate diagnostics and initial information on staging (Tuttle & Sherman, 2024).

Staging
All ATCs are considered stage IV. Stage IVA patients have intrathyroidal tumors. Stage IVB patients have extrathyroidal tumors and no distant metastatic disease. Stage IVC patients have distant metastasis (Limaiem et al. 2023).

Treatment Modalities
The stage of the disease and molecular testing guide the treatment selection. Treatment consists of chemoradiation and evaluation for resection. Given the very rapid progression of the disease and poor treatment outcomes, it is first important to counsel the patient and family and establish goals of care (Tuttle & Sherman, 2024). Palliative/comfort-oriented care and end-of-life planning are integral components of disease management for patients with ATC.

Prognosis
ATC is poorly responsive to treatment modalities and carries a nearly 100% mortality rate. In patients with advanced disease without targetable mutations, palliative/hospice care should be initiated.