Thyroid metastasis from hepatocellular carcinoma: a rare case report and literature review

Abstract

Background: Thyroid metastasis is a relatively uncommon event in clinical practice, typically occurs in more prevalent primary tumors, including renal cell carcinoma and cancers of the gastrointestinal tract, lungs, and breast. The incidence of thyroid metastasis from primary hepatocellular carcinoma (HCC) is particularly infrequent. This case report outlines the clinical challenges and diagnostic pathway associated with a thyroid mass in a patient with HCC, highlighting the rarity and intricacy of such metastatic associations.

Case presentation: A 51-year-old male with a long-standing history of hepatitis B-related liver cirrhosis presented with a rapidly enlarging painful left-sided thyroid mass 28 months after a diagnosis of HCC. FDG-PET/CT imaging revealed a 6 cm hypodense tumor in the left lobe of the thyroid and further fine needle aspiration cytology and biopsy (FNAB) confirmed it as a metastasis from HCC. The patient underwent transcatheter arterial chemotherapy embolization (TACE) as a first attempt to control the progress of the thyroid lesion. However, subsequent imaging showed a continued progression of the lesions in liver, along with other metastatic sites. Although multiple interventions, such as radiofrequency ablation (RFA) procedures was administered due to the progression of liver cancer and embolization therapies for the thyroid, the patient experienced significant deterioration, presenting with respiratory failure due to malignant pleural effusion.

Conclusions: This unique case highlights the importance of promptly considering persistent or newly developed thyroid nodules as indicative of metastatic disease. The identification of thyroid metastases, especially in the context of extensive organ involvement, often correlates with a poor prognosis. Given the distinctive physiological properties of the thyroid gland, multidisciplinary management may offer clinical benefits for such patients with complex metastatic profiles. Combining locoregional therapies with immunotherapy, particularly dual immunotherapy, may offer significant prognostic advantages. Nevertheless, these hypotheses need to be verified through large-scale clinical trials.

Keywords: case report; hepatocellular carcinoma; liver cancer; thyroid metastasis; transcatheter arterial chemotherapy embolization (TACE).

Figure 1

Enhanced abdominal MRI indicated a small nodule in the anterior segment of the right lobe of the liver, consistent with primary hepatocellular carcinoma.

Figure 2

The FDG-PET/CT showing a highly metabolic focus in the the left lobe of the thyroid. FDG-PET/CT, fluorodeoxyglucose positron emission tomography/computed tomography.

Figure 3

(A) FNAB of the thyroid, post HE, corroborates the pathology of hepatocellular carcinoma metastasized to the thyroid. Immunohistochemical examination was positive for AFP (B) and GPC3 (C), and negative for TG (D) and TTF-1 (E) (HE magnification of 200x). AFP, alpha-fetoprotein; FNAB, fine needle aspiration biopsy; GPC3, glypican-3; HE, hematoxylin and eosin staining; TG, thyroglobulin; TTF-1, thyroid transcription factor-1.

Figure 4

(A) A cervical enhanced CT scan on June 2017 indicated an irregular mass in the left thyroid lobe and enlarged lymph nodes in the left carotid sheath (arrow). (B) A cervical enhanced CT scan on November 2017 indicated an irregular mass in the left thyroid lobe consistent with metastasis, with adjacent destruction of the thyroid cartilage, involvement of the left hypopharynx, and possible thrombosis of the left internal jugular vein.

Figure 5

Timeline of clinical rvents. HCC, hepatocellular carcinoma; PD, progression disease; RFA, radiofrequency ablation; SD, stable disease; TACE, transcatheter arterial chemotherapy embolization.