A Systematic Review and Meta-Analysis on Sediment Cytology: An Adjunct to Early Diagnosis

Sediment cytology, initially applied in urinary diagnostics, has expanded to formalin-fixed biopsy specimens, evaluating exfoliated cells suspended in formalin fixative. Though traditionally discarded, this sediment contains diagnostic material, especially in friable or malignant tissues. It offers a rapid, cost-effective, preliminary diagnostic tool when histopathology is delayed, such as in bone lesions requiring decalcification. This systematic review aimed to comprehensively assess the diagnostic accuracy, applicability, and limitations of sediment cytology across diverse anatomical sites.

This systematic review followed PRISMA guidelines, and an electronic search was conducted across PubMed, Scopus, and Google Scholar databases until January 1, 2025, without year restrictions. Keywords included "Sediment cytology," "oral neoplasms," "bone lesions," and related terms. Articles in English reporting sediment cytology on formalin-fixed biopsies with cytological-histological correlation were included.

Nine eligible studies were identified, involving various lesions including oral squamous cell carcinoma (OSCC), oral potentially malignant disorders (OPMDs), bone lesions, GIT, and cervical and ovarian neoplasms. Pooled sensitivity and specificity were 73.3% and 92.1%, respectively. Subgroup analysis revealed excellent concordance for OSCC and bone malignancies. Sensitivity was lower in benign lesions and OPMDs, attributed to poor cellularity and exfoliation. Methodological heterogeneity was noted, though overall bias remained low.

Sediment cytology shows valuable diagnostic potential as a preliminary adjunct to histopathology, particularly for malignancies, warranting further standardized multicenter studies.