The Bethesda system for reporting thyroid cytopathology: an institutional experience of the outcome of indeterminate categories

OBJECTIVE

In this study, we investigated the efficacy of the Bethesda system (TBS) for reporting thyroid cytopathology in determining the risk of malignancy for indeterminate cases. These cases comprised atypia or follicular lesion of undetermined significance (AUS/FLUS), follicular neoplasia or suspicious for follicular neoplasia (FN/SFN) and suspicious for malignancy (SM) categories. AUS/FLUS cases were further subcategorized according to their patterns, and the malignancy rate for each subcategory was calculated.

METHODS

A total of 6310 thyroid fine needle aspiration (FNA) cases were analysed and 655 indeterminate cases were enrolled in the study. AUS/FLUS cases were further subcategorized into four patterns as follows: papillary thyroid carcinoma (PTC) pattern, microfollicle pattern, atypical cell pattern and Hürthle cell pattern.

RESULTS

Malignancy rates for AUS/FLUS, FN/SFN and SM were 18.9%, 45.7% and 71%, respectively. Malignancy rates for AUS/FLUS subcategories were as follows: PTC pattern, 28%; microfollicle pattern, 6.9%; atypical cell pattern, 22.2%; and Hürthle cell pattern, 0%.

CONCLUSION

The Bethesda system categorizes thyroid FNAs with increasing risk of malignancy as advocated. However, our findings suggest that the risk of malignancy for AUS/FLUS might be higher than estimated. Particularly, AUS/FLUS cases with focal features suggestive of PTC seem to be associated with a much higher risk of malignancy than other patterns.

Pseudopapillary pattern in intra-operative squash smear preparations of central nervous system germinomas

BACKGROUND

Although the morphology of central nervous system (CNS) germ cell tumours is very similar to that of gonadal germ cell tumours, some architectural changes may dominate the microscopic appearance of CNS germinomas leading to misdiagnosis at low-power magnification.

METHODS

We report five cases of CNS germinoma demonstrating delicate pseudopapillary fronds on squash smear preparations.

RESULTS

The age of the patients ranged from 5 to 21 years (mean 14). Three were female and two male. Three patients presented with symptoms of diabetes insipidus, including polydipsia and polyuria, while absence seizures, meaningless speech, hemiparesia, weight loss, insufficient breast development, amenorrhoea and symptoms of raised intracranial pressure were also encountered depending on the location of the tumours. Tumours were located in the hypophysis in two cases and in the suprasellar region in three. During the intra-operative pathological consultation, evenly distributed pseudopapillary or papillary structures formed the dominant pattern in the squash preparations of all cases. The neoplastic cells were characterized by pale variably vacuolated cytoplasm, pleomorphic nuclei with irregular membranes, and several prominent nucleoli. Variable numbers of small lymphocytes were also found.

CONCLUSION

Intracranial germinomas may commonly exhibit a pseudopapillary pattern on squash smears that may cause misdiagnosis as neoplasms with papillary morphology. Careful examination of cellular details is essential in order to reach the correct diagnosis.

Persistence and behavior of pesticides in cotton production in Turkish soils

Turkey is the sixth largest producer of cotton in the world. Two of the most commonly applied pesticides used in cotton production are trifluralin and endosulfan. Although both are very effective at controlling pests, their persistence in the environment poses risks to human health and the environment. Four loam soils and one silty-loam soil were studied to evaluate the persistence of trifluralin and endosulfan in relation to soil characteristics. Degradation with trifluralin reached as high as 70% of the applied doses. Soils with the highest organic matter content had the lowest degradation rate, indicating a tighter sorption of trifluralin. Endosulfan degradation was a function of soil type and the specific isomer, with beta-endosulfan depicting the highest degradation.