Morphological Variations of Neutrophils Nuclear Appendages: Sex-Based Differences and Contextual Insights from Sudan

Background: Neutrophil nuclear morphology, with its typical multilobation and other nuclear appendages, is a complex and intriguing area of study. The sex-chromatin drumstick, a well-acknowledged physical characteristic in females, is indicative of the dormant X chromosome. However, its identification is often complicated by non-specific nuclear projections, including sessile nodules, tags, clubs, and hooks, which can manifest in both sexes. The accurate distinction between authentic sex-chromatin appendages and non-specific variations underscores the importance of morphological precision and diagnostic expertise. Objective: To examine and elucidate the morphological spectrum of neutrophil nuclear appendages, highlight sex-based disparities, and address diagnostic factors pertinent to the Sudanese setting. Materials and Methods: A narrative mini-review style was used to synthesize insights from traditional hematology literature and contemporary studies (2018–2024) on neutrophil nuclear morphology, sex-chromatin characteristics, and morphological aberrations, including drumstick and sessile nodule alterations. Local environmental, dietary, and viral aspects relevant to Sudan were integrated to offer contextual interpretation. A functional text-based diagnostic flowchart was created for laboratory use. Results: True drumstick appendages are present in roughly 1–5% of neutrophils in females and are characterized morphologically by a tiny, compact spherical head linked by a slender filament. Non-specific appendages, such as sessile nodules, tags, and hooks, are devoid of this distinguishing filament and are present in both sexes. The Pelger-Huët anomaly (PHA) and acquired pseudo-Pelger-Huët anomaly (PPHA) have distinctive bilobed ("pince-nez") nuclei that are not associated with sex chromatin. In Sudan, folate insufficiency, tuberculosis, HIV infection, and drug exposure may induce morphological heterogeneity and complicate interpretation. Conclusion: Accurate identification of authentic drumstick morphology necessitates stringent criteria to prevent misdiagnosis. Drumsticks indicate sex chromatin; however, other nuclear appendages are non-specific and should not be utilized for sex determination. Nutritional and pathogenic variables may alter neutrophil morphology in the Sudanese population; therefore, local reference data are necessary. The included diagnostic flowchart facilitates uniform classification and reporting in resource-constrained laboratory settings.