A case report of breast cancer and membranous nephropathy with positive anti phospholipase A2 receptor antibodies.

BACKGROUND: Testing for antibodies against podocyte phospholipase A2 receptor-1 (PLA2R) allows clinicians to accurately identify primary membranous nephropathy (MN). Secondary MN is associated with a spectrum of pathology including solid organ malignancy. PLA2R positivity in these patients occurs, although no case of PLA2R-positive MN has been definitively linked to cancer. CASE PRESENTATION: We describe a case of biopsy-proven PLA2R-positive MN, in whom invasive ductal carcinoma of the breast was discovered. The patient underwent surgery and adjuvant chemotherapy (including cyclophosphamide) and went into a sustained complete remission of her nephrotic syndrome. DISCUSSION AND CONCLUSIONS: Case series have reported PLA2R positivity in patients with solid organ malignancy associated MN. Our case is unusual as it is a breast malignancy, and the patients nephrotic syndrome and anti-PLA2Rab titres improved with treatment of the cancer. Here we report, to the best of our knowledge, the first case of oestrogen receptor-2 positive breast cancer associated with PLA2R positive MN in a young lady that was treated successfully by treating the malignancy.