[Clinical importance of thyroid gland cytology]

[Possibilities of the personalized approach to solitary thyroid nodules based on molecular profiling]

BACKGROUND

Molecular profiling is currently not yet widespread in Germany and its potential for personalized treatment of solitary thyroid nodules is not exhausted.

METHOD

Narrative assessment of the available options and their evidence based on the current international literature as well as discussion of the options in the German context from the perspective of a thyroid surgeon and a thyroid pathologist.

RESULTS

The commercial tests available, especially in the USA, for molecular profiling of thyroid nodules offer good rule-in and somewhat poorer rule-out options, as many differentiated thyroid carcinomas do not display genetic alterations. The costs of these tests and molecular pathology for nodule assessment are still high and the individual mutations have not yet been clearly characterized.

CONCLUSION

It can be assumed that molecular profiling will become more important in the coming years and find its way into the clinical routine. At this point in time, however, there is not yet sufficient evidence of the clinical significance of most mutations in thyroid carcinomas to derive therapeutic consequences from them.

[Ultrasound-guided minimally invasive diagnostics and treatment in the head and neck area]

Tumoral lesions in the head and neck region represent a diagnostic and therapeutic challenge in otorhinolaryngologic routine. High-resolution ultrasound is usually able to guide diagnosis. Nevertheless, a definite differentiation between benign and malignant lesions can only be achieved by tissue biopsy. The various options for obtaining samples for histopathological or cytological examination-from minimally invasive ultrasound-guided fine-needle biopsy to punch biopsy and open surgical biopsy-will be discussed in the first part along with the associated advantages and disadvantages. In the second part of this CME article, minimally invasive ultrasound-guided therapeutic options in the head and neck region which can be performed on an outpatient basis are depicted.

[Fine-needle aspiration (FNA) of the thyroid gland : Analysis of discrepancies between cytological and histological diagnoses]

BACKGROUND

Diagnostic problems of thyroid cytology are frequently discussed, but relevance and causes of discrepant cytological and histological diagnoses are rarely studied in detail.

OBJECTIVES

Investigation of causes and relevance of discrepant diagnoses.

MATERIALS AND METHOD

The analysis includes 297 patients who had thyroid resection after prior fine needle aspiration (FNA) and is based on the cytological and histological reports. In special cases, cytological and histological specimens were re-examined.

RESULTS

Malignant tumors were found in 45 patients (15.1 %). In 5 patients the cytological diagnosis was "false negative". Three of these 5 tumors were papillary carcinomas (PTC) of ≤10 mm, one an obviously nonmalignant papillary proliferation of the thyroidal epithelium and one a malignant lymphoma complicating autoimmune thyreoiditis (AIT). In 11 of the 35 patients with a FNA diagnosis "suspicious of malignancy" or "malignant," 1 AIT, 4 goiter nodules, and 6 adenomas were diagnosed histologically. However, since distinct nuclear atypia was found in three of five false positive diagnoses, there still remains doubt in their benignity.

CONCLUSIONS

Carcinomas of ≤10 mm incidentally detected in the resected thyroid tissue may not be relevant to the patient and do not reduce the high negative predictive value of FNA. The final diagnosis on the resected tissue should include the cytological findings. Discrepant findings should be commented in the report to the clinician.

[Lymph node and distant metastases of thyroid gland cancer. Metastases in the thyroid glands]

The different biological features of the various major entities of thyroid cancer, e.g. papillary, follicular, poorly differentiated, anaplastic and medullary, depend to a large extent on their different metastatic spread. Papillary thyroid cancer (PTC) has a propensity for cervical lymphatic spread that occurs in 20-50 % of patients whereas distant metastasis occurs in < 5 % of cases. Cervical lymphadenopathy may be the first symptom particularly of (micro) PTC. In contrast follicular thyroid cancer (FTC) has a marked propensity for vascular but not lymphatic invasion and 10-20 % of FTC develop distant metastases. At the time of diagnosis approximately one third of medullary thyroid cancer (MTC) cases show lymph node metastases, in 10-15 % distant metastases and 25 % develop metastases during the course of the disease. Poorly differentiated (PDTC) and anaplastic thyroid cancer (ATC) spread via both lymphatic and vascular invasion. Thus distant metastases are relatively uncommon in DTC and when they occur, long-term stable disease is the typical clinical course. The major sites of distant metastases are the lungs and bone. Metastases to the brain, breasts, liver, kidneys, muscle and skin are relatively rare or even rare. The thyroid gland itself can be a site of metastases from a variety of other tumors. In autopsy series of patients with disseminated cancer disease, metastases to the thyroid gland were found in up to 10 % of cases. Metastases from other primary tumors to the thyroid gland have been reported in 1.4-3 % of patients who have surgery for suspected cancer of the thyroid gland. The most common primary cancers that metastasize to the thyroid gland are renal cell (48.1 %), colorectal (10.4 %), lung (8.3 %) and breast cancer (7.8 %) and surprisingly often sarcomas (4.0 %).