26 December 2025
: Case report 
Primary Well-Differentiated Neuroendocrine Tumor of the Breast: A Case Report and Literature Review
Challenging differential diagnosis, Unusual or unexpected effect of treatment, Patient complains / malpractice, Rare disease, Educational Purpose (only if useful for a systematic review or synthesis), Rare coexistence of disease or pathology
Sanjna Sai Gudena DEF 1*, Nilesh Digvijay Kashikar E 2, Matthew Charles Wakefield E 3DOI: 10.12659/AJCR.950684
Am J Case Rep 2025; 26:e950684
Table 1 Summary of studies on breast neuroendocrine tumors.
| Source | Variable/feature | BNET (%) | IDC (%) | P value |
|---|---|---|---|---|
| Annals of Surgical Oncology []5 | Age | |||
| <50 | 17.1 | 22.2 | <0.001 | |
| 50–59 | 22.8 | 25.0 | ||
| 60–69 | 25.1 | 26.2 | ||
| ≥70 | 35.0 | 26.6 | ||
| ER status | ||||
| ER(−) | 32.5 | 20.2 | <0.001 | |
| ER(+) | 59.3 | 75.7 | ||
| Unknown | 8.1 | 4.1 | ||
| PR status | ||||
| PR(−) | 37.8 | 29.6 | <0.001 | |
| PR(+) | 52.8 | 65.5 | ||
| Unknown | 9.4 | 4.9 | ||
| HER2 status | ||||
| HER2(−) | 58.7 | 45.6 | <0.001 | |
| HER2(+) | 2.2 | 9.5 | ||
| Unknown | 39.2 | 45.0 | ||
| Disease stage | ||||
| Stage 1 | 27.9 | 46.6 | <0.001 | |
| Stage 2 | 34.6 | 27.3 | ||
| Stage 3 | 12.2 | 8.5 | ||
| Stage 4 | 17.9 | 3.7 | ||
| Unknown | 7.5 | 13.9 | ||
| Breast surgery type | ||||
| No surgery | 24.3 | 6.9 | <0.001 | |
| Lumpectomy | 40.0 | 55.1 | ||
| Mastectomy | 34.7 | 37.6 | ||
| Unknown | 0.9 | 0.3 | ||
| Radiation therapy | ||||
| No | 44.0 | 43.5 | <0.001 | |
| Yes | 53.6 | 53.1 | ||
| Unknown | 2.4 | 3.4 | ||
| Chemotherapy | ||||
| No | 44.0 | 57.6 | <0.001 | |
| Yes | 53.6 | 40.0 | ||
| Unknown | 2.4 | 2.4 | ||
| Disease stage | ||||
| <0.001 | ||||
| Stage 1 | 80 | 1.8 (1.5–2.3) | ||
| Stage 2 | 63 | 2.0 (1.6–2.5) | ||
| Stage 3 | 45 | 1.8 (1.3–2.3) | ||
| Stage 4 | 13 | 1.5 (1.3–1.8) | ||
| BMC Cancer []6 | ||||
| Stage 1 | 74.4 | 89.6 | 0.002 | |
| Stage 2 | 73.9 | 82.4 | <0.0001 | |
| Stage 3 | 58.2 | 72.4 | 0.014 | |
| Stage 4 | 20.7 | 27.9 | NS | |
| All stages | 53.6 | 79.8 | <0.001 | |