Pituitary choriocarcinoma in an adolescent male: tumor-derived CG and GH delay diagnosis

Abstract

Background: Primary intracranial germ cell tumors usually present in the first two decades of life, often with precocious puberty. The most common location is in the pineal gland; suprasellar germ cell tumors are rare. We present an additional case of a suprasellar choriocarcinoma producing GH, and review the literature.

Case: This French Canadian, 17 year-old male presented to the ER with a history of mild weight loss and an episode of syncope while hiking in Mexico, but with no other neurological symptoms. Puberty began at age 13 years (growth spurt: 15-16 years), and he attained an adult height within genetic target by age 16 years. Past medical history was negative except for myopia diagnosed during childhood. System review revealed increased thirst and nocturia. The mother was treated for an oligo-astrocytoma in 2007. Clinical examination showed a euthyroid, well-looking young man with 20 ml testicles. Endocrine evaluation revealed elevated testosterone, mildly elevated PRL, borderline low FT4, and decreased IGF-I, morning cortisol and urine osmolality; tumor markers were positive in serum and CSF (hCG>50 IU/L, AFP>10 ng/mL). A transphenoidal biopsy of a 4.5 cm, homogeneous, non-calcified, suprasellar mass was compatible with the diagnosis of choriocarcinoma and stained intensely for hCG and hGH, presumably the placental variant (GH-V) as previously found in vitro in choriocarcinoma cell lines. Combined chemotherapy and irradiation led to tumor regression and undetectable serum hCG to 36 months of follow-up. He is doing well with no evidence of tumor progression and is on complete hormone replacement therapy.

Conclusions: Choriocarcinomas can have a hormonal profile that delays the development of symptoms, due to hCG stimulation of both the gonadal and thyroid axes. This report corroborates previous in vitro evidence that choriocarcinoma cells are able to make GH-V. To what extent the patient's tumor-derived GH contributed to his normal growth is not known. Prognosis for this intracranial neoplasm is very reserved, although combined radiotherapy and chemotherapy has been successful in our patient now 36 months post-diagnosis.