Systematic Review and Meta-Analysis of the Diagnostic Accuracy of the Sydney System for Reporting Lymph Node Fine-Needle Aspiration Biopsy in Diagnosing Malignancy.

INTRODUCTION: The aim of the study was to perform the first meta-analysis for assessment of the pooled risk of malignancy of each category of the Sydney system for reporting of lymph nodal aspirates along with the evaluation of diagnostic accuracy. METHODS: PubMed/MEDLINE and Embase were searched with the following keywords: "(Lymph node) AND (fine needle aspiration biopsy) OR (International system OR Sydney system)" in the timeframe 2020 to August 4, 2023. The selected articles were assessed for the risk of bias by the QUADAS-2 tool. The meta-analysis for sensitivity (SN) and specificity for each cut-off, that is, "atypical considered positive," "suspicious of malignancy considered positive," and "malignant considered positive" for the lesions, was carried out after excluding the inadequate samples in each study. To assess the diagnostic accuracy, summary receiver operating characteristic curves were constructed, and the diagnostic odds ratio was pooled in both scenarios. RESULTS: Nine studies, all of which were retrospective cross-sectional studies, were evaluated with a total of 13,205 cases. The SN and specificity for the "atypical and higher risk categories" considered positive for malignancy were 97% (95% CI, 95-99%) and 96% (95% CI, 91-98%), respectively. The SN and specificity for the "suspicious of malignancy and higher risk categories" considered positive for malignancy were 91% (95% CI, 85-95%) and 99% (95% CI, 97-100%), respectively. The SN and specificity for the "malignant" considered positive for malignancy were 75% (95% CI, 65-84%) and 100% (95% CI, 99-100%), respectively. The pooled area under the curve was 99-100% for each of the cut-offs. CONCLUSION: This meta-analysis highlights the accuracy of the Sydney system in reporting lymph node aspirates. It exhibits the significance of the "suspicious" and "malignant" categories in diagnosing malignancy and of the "benign" category in excluding malignancy.

Pituitary tuberculoma with panhypopituitarism masquerading as a pituitary adenoma.

Tuberculosis of the hypothalamo-pituitary axis is extremely uncommon. The presentation of panhypopituitarism in a case of sellar tuberculosis is an even rarer occurrence. We present a case of a 44-year-old man who presented with complaints of headache and right-sided diminution of vision for six months. A hormone profile showed abnormal anterior pituitary assay suggestive of panhypopituitarism. Magnetic Resonance imaging of the brain showed a sellar mass measuring 1.8 × 1.5 × 1.3 cm with suprasellar extension suggestive of a pituitary adenoma. Histopathological examination showed multiple epithelioid cell granulomas along with Langhans giant cells and mixed inflammatory infiltrates against a necrotic background. Zeihl Neelson stain demonstrated the presence of acid-fast bacilli. Thus, a final diagnosis of pituitary tuberculoma was made, and the patient started on antitubercular therapy. It is extremely important to correctly diagnose sellar tuberculosis as the treatment is entirely different, and the patient usually responds well to therapy.

A rare case of primary neuroendocrine carcinoma of the central nervous system.

Primary neuroendocrine carcinoma (NEC) of the brain is an extremely rare presentation, with only a few previous case reports. We describe a primary NEC arising from the left parieto-occipital lobe. The 55-year-old patient presented with complaints of headache and dizziness for the preceding 7 months. Magnetic resonance imaging revealed a large ill-defined mass in the left parieto-occipital lobe, with possible differential diagnosis of meningioma. A craniotomy was performed, and a firm vascular tumor was removed. Histopathological examination revealed a large cell NEC. Immunohistochemistry was performed to exclude the possibility of an extracranial primary. Based on the immunohistochemical expression and absence of any extracranial tumor on positron emission tomography, the diagnosis of primary NEC of the brain was made. It is important to differentiate between primary and metastatic neuroendocrine tumors because they show a significant difference in prognosis and treatment.