Histopathological Spectrum of Breast Lesions and Factors Associated with Malignancy in Mogadishu, Somalia: A Retrospective Cross-Sectional Study

<title>Abstract</title> <p>Background Breast pathology in Somalia remains poorly characterized, with few studies examining the histopathological spectrum or factors associated with malignancy in this post-conflict, low-resource setting. This study described the distribution of breast lesion diagnoses and identified factors independently associated with malignant outcomes in Mogadishu, Somalia. Methods A retrospective cross-sectional study utilized secondary histopathological data from 522 breast specimens collected across multiple healthcare facilities in Mogadishu (July 2021–December 2025). Multivariable binary logistic regression was applied following systematic data cleaning and bivariate analyses. Model discrimination was assessed by AUC with 95% bootstrap CI, Nagelkerke R², and the Hosmer–Lemeshow (HL) test. Four pre-specified sensitivity analyses were conducted. Results Of 522 cases (97.1% female; median age 35 years, IQR: 24–50), 437 had definitive outcomes: 262 benign (59.9%) and 175 malignant (40.1%). Fibroadenoma/adenoma was the most common diagnosis (n = 173, 33.1%), followed by invasive ductal carcinoma/NST (n = 101, 19.3%). Malignant cases were significantly older (median 45 vs. 25 years; p &lt; 0.001) and presented with larger tumors (median 5.0 vs. 3.5 cm; p &lt; 0.001). In multivariable analysis (n = 369 complete cases), increasing age (OR 1.11, 95% CI: 1.08–1.13, p &lt; 0.001) and tumor size &gt; 5 cm (OR 1.90, 95% CI: 1.06–3.39, p = 0.030) were independently associated with malignancy, while tumor size ≤ 2 cm was inversely associated (OR 0.15, 95% CI: 0.06–0.41, p &lt; 0.001). The model demonstrated excellent discrimination (AUC = 0.876, 95% CI: 0.841–0.909; Nagelkerke R²=0.493). The HL test indicated calibration mismatch (χ²=22.6, p = 0.004), consistent with the parsimonious exploratory model. Sensitivity analyses confirmed robustness across all scenarios. Conclusion Fibroadenoma dominates among younger women, while malignancy — predominantly invasive ductal carcinoma — presents with larger tumor size among older patients. Age and tumor size were independently associated with malignant outcome. These findings support heightened awareness and earlier clinical evaluation among women aged approximately 35 years and older, alongside investment in standardized histopathological reporting infrastructure in Somalia and comparable settings.</p>