Cytopathology最新文献

Background

Thyroid tumours occur in patients with Birt-Hogg-Dubé syndrome (BHD), a condition caused by germline alterations in the FLCN gene that confers an increased cancer risk. Somatic FLCN mutations may also contribute to tumorigenesis. In this study, we present the first description of the cytopathology of two thyroid tumours evaluated by fine-needle aspiration (FNA) and harbouring pathogenic FLCN mutations.

Methods

We encountered two patients with oncocytic thyroid tumours in which comprehensive next-generation sequencing (NGS) identified pathogenic FLCN mutations. We present the FNA cytologic findings and corresponding histopathology, and discuss the diagnostic challenges posed by the FNAs, one of which was initially confounded by negative preoperative molecular testing.

Results

Both patients were middle-aged females. Patient 1 had an incidental thyroid nodule and a history of BHD. FNA of a TI-RADS 5 mass was diagnosed as suspicious for papillary thyroid carcinoma (PTC), Bethesda V, leading to total thyroidectomy. Patient 2 presented with a palpable nodule. Compressive symptoms prompted lobectomy, revealing an angioinvasive oncocytic carcinoma. Subsequent FNA findings of a metastasis cytologically resembled oncocytic PTC; however, it was correctly diagnosed as oncocytic carcinoma after correlation with prior histologic findings. Expanded NGS testing facilitated the final diagnosis of FLCN-mutated oncocytic adenoma in Patient 1 and high-grade differentiated oncocytic carcinoma in Patient 2.

Conclusion

Thyroid tumours harbouring FLCN mutations with oncocytic features may mimic PTC cytologically. Although rare, correct diagnosis of these tumours is essential to ensure appropriate treatment. For early detection, patients with BHD may benefit from thyroid ultrasound surveillance.

Objective

To evaluate the application of The International System for Serous Fluid Cytopathology (TIS) in cytology cases of cerebrospinal fluid (CSF).

Methods

A retrospective analysis was conducted on 618 CSF samples from two hospitals in Athens, Greece, over a 5-year period. CSF samples were processed with conventional cytological techniques or liquid-based preparations, stained with Giemsa and Papanicolaou staining. Immunocytochemistry was used when necessary. Samples were classified by two cytopathologists into the five TIS categories: nondiagnostic (ND), negative for malignancy (NFM), atypia of undetermined significance (AUS), suspicious for malignancy (SFM) and malignant (MAL).

Results

Of the 618 CSF samples, 78.8% were classified as NFM, 19.4% as MAL and 1.3% as ND. Only 0.5% of cases were categorised as AUS, and no cases were classified as SFM. In patients with a history of neoplasia and suspected CSF involvement, the malignancy detection rate was 38%, while it was only 5.6% in patients with neurological symptoms but no known neoplasia. The most common metastatic cancers in the CSF were breast carcinoma, lung adenocarcinoma and lymphomas.

Conclusions

The classification of CSF cytology samples using TIS proved to be feasible and effective. Notably, the majority of samples fell into the NFM and MAL categories, while the AUS and ND categories were rare. These findings suggest that this classification could provide a reliable framework for CSF cytology reporting, improving diagnostic accuracy and potentially aiding in clinical decision-making.

Two-Liner: This study offers proof of the value of the application of The International System for Serous Fluid Cytopathology in the cytological interpretation of cases of cerebrospinal fluid.