Endocrine Abstracts

Background: MTC tends to metastasize early in the course of the disease affecting usually regional lymph nodes; in 7–23% of patients distant metastases may be present at diagnosis (common metastatic sites:liver, lungs, bone). We present two MTC cases with unusual metastases to the breast, pancreas and mandible.

Case presentation: Patient No 1: a 48-year-old female was diagnosed with MTC in 1990. Total thyroidectomy was performed followed by neck dissection. Ten years later, cervical and mediastinum lymph node dissection took place. In 2009, disease progression was confirmed by elevated Calcitonin and CEA levels along with a positive uptake (Octreoscan) in mediastinum and liver. A bone scan revealed additional metastases in the thoracic spine and external bone radiotherapy and liver chemoembolisation were performed. In 2013, mediastinum MRI revealed a lesion in the right breast confirmed by mammography. Histology of breast tumorectomy confirmed MTC metastasis and treatment with vandetanib was initiated. Patient No 2: a 55-year-old female was diagnosed with MTC in 2003. Total thyroidectomy with neck dissection was performed. Due to cervical nodal metastases, she underwent modified radical neck dissections. In 2014, recurrent metastatic disease in the right shoulder was confirmed by MRI and external radiotherapy was performed. Furthermore, an abdominal MRI revealed a head pancreatic tumor. MTC metastasis was confirmed by biopsy and treatment with vandetanib was initiated. Additionally, the histology of a resected painful mass in the right mandible revealed a well differentiated MTC.

Conclusions: These two MTC cases, although apparently rare, highlight the need for watchful care and prompt recognition of unexpected metastases in MTC patients.