Non-gynaecological Cytology
Thyroid cytology
Anatomy and physiology of the thyroid
Thyroid nodules
Classification of thyroid neoplasms
Fine needle aspiration (FNA)
Adequacy of the specimen
Evaluation of the specimen
Terminology for reporting results
Benign conditions
The follicular lesions
Malignant tumours
Parathyroid tumours

Follicular adenoma

It is a benign neoplasm, presenting as a single nodule, usually not greater than 3 cm in diameter. Some of them can produce thyroid hormones and consequently cause hyperthyroidism (functioning or 'hot' adenomas). The hystologic pattern may vary: macrofollicular (composed of large follicles filled with colloid), microfollicular (with smaller follicles), trabecular (with follicular cells arranged in ribbons).

Classification (no prognostic significance)

  • simple
  • microfollicular
  • trabecular
  • oxyphil
  • atypical
  • papillary
  • signet ring cell
Nodular hyperplasia Follicular neoplasia
multiple solitary
poorly encapsulated encapsulated
architectural heterogeneity uniformity of the architecture
cytologic heterogeneity cytologic homogeneity
comparable areas in adjacent gland different from surrounding gland
no compression of surrounding gland compression of surrounding gland

 

Microfollicular groups
Microfollicular adenoma (histology)

 

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