Agradecimentos: This study was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Finance Code 001), Brazil. Fernanda Aragão Felix, Ana Carolina Velasco Pondé de Sena, Thalita Soares Tavares, and José Alcides Almeida de Arruda are recipients of fellowships. We also thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (305493/2018-3; 435644/2018-1; 404710/2018-2; 310797/2019-5; 302157/2017-4). Lucas Guimarães Abreu, Pablo Agustin Vargas, Felipe Paiva Fonseca, Tarcília Aparecida Silva, and Ricardo Alves Mesquita are research fellows of CNPq. Mrs E. Greene provided English editing of the manuscript Ver menos

Abstract: Cytopathologic analysis is feasible and provides detailed morphological characterisation of head and neck lesions. To integrate the available data published on fine-needle aspiration cytology (FNAC) used for the diagnosis of plasma cell neoplasms (PCN) of the head and neck region. Searches on PubMed, Web of Science, Embase, and Scopus were performed to compile data from case reports/case series published in English. The Joanna Briggs Institute tool was used for the critical appraisal of studies. A total of 82 studies comprising 102 patients were included in this review. There was a predilection for men (68.6%) (male/female ratio: 2.1:1). Individuals in their 50s (29.4%), 60s (22.5%), and 70s (22.5%) were more often affected. The thyroid gland (26.2%) was the main anatomical location, followed by scalp (15.5%), neck/cervical region (15.5%), jaws (13.6%), and major salivary glands (13.6%). For FNAC analysis, a smear was employed in 41 (40.6%) cases and a cell block was used in four (3.9%). In 56 (55.4%) reports, no cytological methods were available. Morphologically, 34 (56.7%) cases had a diagnosis of PCN with agreement between cytopathology and histopathology. The rate of wrong diagnoses when using cytology was 27.5%. Immunophenotyping was performed in 49 (48%) of the cases. The 69-month disease-free survival rate was 60.2%, while the 27-month overall survival rate was 64.1%. This study reinforces that FNAC can be an ancillary tool in the first step towards the diagnosis of PCN of the head and neck region, especially when applying a cell block for cytological analysis Ver menos