Introduction: Breast cancer remains a major global health burden, and lymph node involvement is a key pathologic indicator of tumor spread, prognosis, and postoperative treatment planning in patients undergoing mastectomy. Accurate nodal assessment also improves disease staging and therapeutic decision-making. This study aims to evaluate the pathologic status of lymph node involvement in patients undergoing mastectomy.

Material and methods: This retrospective descriptive cross-sectional study was conducted at Shahid Madani Hospital in Tabriz on 250 patients selected by convenience sampling, with sample size estimated using Cochran’s formula. Data were extracted from archived medical and pathology records, and clinicopathologic variables, particularly lymph node status and related breast tumor characteristics, were systematically collected and analyzed to evaluate the pattern of nodal involvement in mastectomy patients.

Results: Among 250 mastectomy patients, invasive ductal carcinoma was the predominant subtype (79.2%), most tumors were grade II (57.2%), and mean tumor size was 3.41 ± 1.67 cm. Lymph node involvement was present in 58.4%, with macrometastasis in 51.2% and extranodal extension in 15.6%. Nodal positivity was significantly associated with larger tumor size (3.98 ± 1.78 vs. 2.61 ± 1.14 cm, P < 0.001), higher grade (P = 0.002), and lymphovascular invasion (60.3% vs. 23.1%, P < 0.001).

Conclusion: These findings indicate that lymph node metastasis is common in mastectomy specimens and is closely linked to adverse pathologic features. Larger tumors, higher histologic grade, and lymphovascular invasion appear to be the strongest correlates of nodal spread, underscoring the importance of careful pathologic lymph node assessment for accurate staging, prognostic stratification, and postoperative treatment planning in breast cancer patients.