To highlight the potential of
temozolomide (TMZ) to induce rapid
tumor regression in patients with aggressive
corticotroph adenomas (CA) that are refractory to surgery and
radiation therapy and to review use of TMZ in other
pituitary tumors. We present a case of a 56-year-old male with a 3 cm CA treated with transphenoidal surgery (TSS) and conventional
radiotherapy in the same year. His hypercortisolemia recurred 11 years later with rapid
tumor growth (to 4.2 × 2.5 cm) and he underwent a second TSS with good resection. The
tumor recurred 6 months later with
ophthalmoplegia. Over 16 months he underwent an additional three surgeries (two TSS, one
craniotomy) and repeated conventional
radiotherapy. Ki67 staining index on surgical specimens was 5-6%.
Temozolomide is an oral
alkylating agent approved for
glioblastoma multiforme treatment that has only recently shown promise in treating some
pituitary tumors. In this patient TMZ was started at 150 mg/m²/day, titrated to 200 mg/m²/day, taken 5 days per month. The only significant side effect was moderate
nausea. After 10 weeks, the
tumor showed a remarkable 60% regression with objective improvement in
ophthalmoplegia. Treatment of aggressive CAs represents a therapeutic challenge and in some cases surgical debulking and
radiotherapy are of limited success. Few reports of CAs responsive to TMZ have been reported in the literature. To our knowledge, this case represents the most rapid robust CA shrinkage response reported to date. Further randomized clinical trials of TMZ in the treatment of aggressive
pituitary adenomas are warranted.