Like papillary cancer, follicular cancer is a well-differentiated tumour. Follicular cancers have a poorer prognosis than papillary tumours and occur in an older age group. They spread by the blood stream and rarely spread to the lymph nodes of the neck. There are two types:
This type of tumour is highly aggressive and needs to be treated with great care because there is a 50% mortality as compared to the minimally invasive tumour where there is only a 3% mortality. The separation of the two entities is crucial and emphasizes the need for a pathologist with a special interest in endocrine pathology. An elegant study by the Oxford Molecular Group in the UK has shown that the binding of lectin Helix pomatia agglutin (HPA) in follicular thyroid neoplasms is a marker for patient recurrence and survival.Patients with HPA positivetumours had a 10 year survival of 78% while the negative tumour survival at 10 years was 98%.
This tumour has an excellent prognosis and as a result some surgeons, treat lesions of 3cms in diameter in women under 50 years old withlimited surgery (lobectomy).
Cytological slides of follicular cancer of the thyroid - click either to enlarge