4. Hrvatski kongres kliniËke citologije 4th Croatian Congress ... - Penta

Clinical Cytology - Plenary and Invited Lectures
IMPLEMENTATION OF MODERN TECHNIQUES IN FNA OF THE THYROID
Tötsch M
Institute of Pathology and Neuropathology, University Hospital of Essen, Germany
Fine needle aspiration of the thyroid started in the middle of the last century. It rapidly
proved to be an excellent tool for management of thyroid nodules. Sensitivity of
the method was improved significantly be the introduction of scintigraphy and ultrasonography.
Later on, not only management but also the diagnosis of certain entities as
papillary carcinoma or anaplastic carcinoma became possible by establishing appropriate
diagnostic criteria. Nowadays fine needle aspiration biopsy has become a standard
procedure, cytopathology has become adopted in the WHO - Classification of thyroid
tumours (2004). Actually there is discussion concerning the diagnostic categories to be
used as well as the definition of “non satisfactory” and satisfactory”, respectively. Additionally,
the benefit of liquid based cytology is under evaluation. However, comparison
of studies is hampered by different interpretation of the parameters mentioned above,
furthermore the rate of incidental thyroid cancer in interpretation of “false-negative”
results must be taken in consideration.
The introduction of ancillary tests has improved the diagnostic sensitivity and specificity
of cytology. While in former times DNA-cytometry and morphometry have been tried as
an adjunct in discriminating follicular tumours, immunocytochemistry has proven now
its value in the diagnosis of medullary carcinoma and metastases. Galectin-3 and others,
however, can not be used today with reliabilty in practical diagnostic work.
Nowadays, emphasis is laid on the introduction of molecular tests and lymphomas can
be reliable diagnosed in most cases. Papillary carcinoma, having already a very good
detection rate by cytology, may be diagnosed by investigation of the RET-RAS-BRAF-
MAPK-pathway as well. Unfortunately, routine use is hampered by false negative respectively
false positive results. Therefore, interest shifts to diagnosis of this tumour
type by the detection of specific miRNA profiles.
However, till now, there is no diagnostic tool for solving the dilemma of thyroid cytology,
the distinction of follicular adenoma from follicular carcinoma. In these cases the diagnosis
can be made only by histology.
Martin.Toetsch@medizin.uni-essen.de
67
4 th Croatian Congress of Clinical Cytology / 1 st Croatian Symposium of Analytical Cytology / 2 nd Croatian Symposium of Cytotechnology