Problems with the evaluation of response after induction chemotherapy in breast cancer.

cells that have been conveyed to that organ by the arteries [3]. Several theories have been postulated to account for the low incidence of metastases to the spleen compared to other parenchymatous organs [4], including a possible role of spleen contractions in forcing the blood from the sinusoids into the splenic vein which keeps tumour cells in constant motion. The 2 patients we describe here had spleen metastases from ovarian and colonic cancer in the absence of other distant organ involvement. These unusual presentations of advanced disease raise the question of whether an underlying condition may represent a risk factor for spleen colonisation in subjects with solid tumours. Both patients had liver cirrhosis causing portal hypertension. When the portal venous pressure rises, blood stasis, retrograde blood flow and diversion of portal blood into systemic veins, in an attempt to decompress the portal system, can occur. We suggest, that in such conditions, a neoplastic embolus may reach the spleen via the mesenteric veins and by retrograde blood flow in the splenic vein. Moreover, implantation of neoplastic cells may be facilitated by blood stasis which increases the time of contact with the splenic tissue. The 2 cases described here seem to support this hypothesis. Patient 1 had primary ovarian cancer involving the sigmoid colon and patient 2 had a primary tumour of the descending colon; the venous system of the left region of the colon drains into the portal circulation via the inferior mesenteric vein which enters the splenic vein. Whether neoplastic cells from tumours draining into the portal system can more easily seed the spleen in patients with portal hypertension needs to be confirmed. However, based on our experience, we suggest a more careful evaluation of the spleen at intervention and during follow-up in these subjects.