A rare case of a giant prolactinoma with atypical histological features: 5 years of follow-up.

ABSTRACT

BACKGROUND: Giant prolactinomas are rare in childhood and adolescence and represent a challenge in diagnosis and management. CASE PRESENTATION A 15.7-year-old male adolescent presented with short stature and delayed puberty. On clinical examination, mild right central VII paresis, gait instability, decreased visual acuity, and impaired visual fields were noted. Investigations showed hyperprolactinemia (2209 ng/mL), secondary hypothyroidism, hypogonadotropic hypogonadism, and growth hormone deficiency. Imaging studies showed an enormous invasive skull base mass. Craniotomy was undertaken to debulk the tumor and perform biopsies. Histology revealed a very large atypical, prolactin-secreting pituitary macroadenoma, i.e., a giant prolactinoma. After commencing cabergoline treatment, prolactin concentrations decreased in 5 months and normalized 18 months later, while significant shrinkage of the tumor was observed. The diagnostic work-up for genetic syndromes often associated with sporadic macroadenomas was negative. CONCLUSION: Giant prolactinomas presenting with multiple pituitary hormone deficiencies in childhood or adolescence are rare and require prompt diagnosis and multidisciplinary management.