Metastatic lobular breast carcinoma positive for syndecan-1 mimicking a plasma cell neoplasm: a case report
Journal of Trends in Medical Investigation (JTMI), vol.2, no.1, pp.44-51, 2026 (Peer-Reviewed Journal)
- Publication Type: Article / Case Report
- Volume: 2 Issue: 1
- Publication Date: 2026
- Doi Number: 10.12345/jtmi.2026.18
- Journal Name: Journal of Trends in Medical Investigation (JTMI)
- Journal Indexes: Other Indexes
- Page Numbers: pp.44-51
- Open Archive Collection: AVESIS Open Access Collection
- Kocaeli University Affiliated: Yes
Abstract
The metastases of breast cancer to bone marrow can mimic plasma cell neoplasia morphologically due to
presence of plasma cell-like neoplastic cells and even positive staining for a carcinoma metastasis with plasma
cell marker CD138/ Syndecan-1 may cause confusion in diagnosis. This case report details a 71-year-old female
initially suspected of plasma cell myeloma due to hypercalcemia and multiple lytic bone lesions. However,
a bone marrow biopsy revealed syndecan-1 positive metastatic lobular breast cancer mimicking a plasma
cell neoplasm. Bone marrow aspirate smears and the bone marrow biopsy showed plasmacytoid cells that
were strongly positive for syndecan-1, indicating metastatic lobular breast carcinoma. The overexpression of
syndecan-1 was a critical marker in identifying the breast cancer cells, emphasizing the diagnostic challenges
when syndecan-1 positive metastatic lobular BC presents with plasmacytoid features.