Unexpected thrombocytopenia of a rare tamoxifen-induced complication in breast cancer therapy: A case report.

BACKGROUND

Tamoxifen, a selective estrogen receptor modulator, is pivotal in managing hormone receptor-positive breast cancer. While its common side effects are well-documented, tamoxifen-induced thrombocytopenia is a rare, serious adverse event requiring drug discontinuation.

CASE SUMMARY: We report a case of tamoxifen-induced thrombocytopenia in a 51-year-old premenopausal woman with breast cancer, occurring within 4 weeks of initiating adjuvant tamoxifen therapy. Platelet counts normalized after drug cessation, but thrombocytopenia recurred upon rechallenge, leading to permanent discontinuation.

CONCLUSION

This case underscores the need for regular complete blood count monitoring in patients on tamoxifen to detect rare hematologic adverse events promptly.