BACKGROUND: Diverse complications have been reported in association wi
th the growth and medical treatment of uterine leiomyomata. Infarction
and necrosis may be common and incite complications from parasitic va
scular attachment, pain and thrombosis. The rarity of severe complicat
ions in this situation warrants presentation of the following unique a
ssociation. CASE: A 33-year-old female, gravida 1, para 1, was treated
with gonadotropin-releasing hormone agonist (GnRH-a) for three months
prior to laparotomy and removal of a solitary, 5,190-g, pedunculated
myoma. The mass had secured an additional vascular supply fi om the tr
ansverse colon and omentum. Although the immediate postoperative cours
e was uncomplicated, delayed onset of abdominal pain and fever lead to
the diagnosis of superior mesenteric and portal vein thrombosis. Port
al vein thrombosis responded to thrombolytic infusion into the superio
r mesenteric artery. Superior mesenteric vein thrombosis persisted, wi
th evidence of early vascular recanalization. After six weeks of addit
ional anticoagulation, assessment by computed tomographic scan showed
complete resolution of all thrombi. CONCLUSION: While thrombosis has b
een reported with GnRH-a therapy in men with prostate cancer, its asso
ciation with treatment in this benign case may have been a consequence
of the massive tumor size. Steroid hormone deprivation potentially co
ntributed to neovascularization and bowel involvement.