Breast cancer metastasis to the spleen: a case report and literature review.

Splenic metastasis from cancers is extremely rare. They usually occur and are detected simultaneously with metastasis to other organs. We present a case of splenic metastasis from carcinoma of the breast occurring 5 years after initial treatment. The metastatic recurrence was an oligometastic form made from the association of a unique bone metastasis to a rib and the metastasis to the spleen. Treatment of the metastatic recurrence was a second line hormonotherapy as the primitive tumor was estrogen receptors positive and gave a 2 year's long control of the disease. A clinical progression occurred then, the patient complained from pain in the left hypochondrium and was objective on [18F]-FDG PET which leaded to splenectomy. This case is being reported because of the rarity of the lesion and its originality is the first reported case with use of an in vivo demonstration of estrogen receptors expression in the spleen metastasis using PET/CT with 16α-[18F]-Fluoroestradiol.