SB, a 54-year-old male, was diagnosed with NF1 aged 11 on the basis of multiple café au lait spots and neurofibromas. In 1991 he presented with diarrhoea and weightloss and investigations revealed a duodenal mass and suspected hepatic metastases. Somatostatin levels were elevated, and histology confirmed a duodenal somatostatinma following Whipples procedure in 1991. The hepatic metastases were excised with good results. At follow up, SB remained symptom free treated only with Creon supplements. An Indium-111 Octreotide scan in 2001 showed normal distribution with no evidence of recurrence. Unfortunately, he represented in 2010 with abdominal pain, jaundice, and diarrhoea. Somatostatin levels increased to 684 nmol/l (NR<150 nmol/l), having been <495 nmol/l during the years of radiological stability. CT imaging revealed recurrent hepatic disease obstructing the common bile duct along with significant paraaortic and mesenteric lymphadenopathy. Gallium 68 DOTATATE PET CT scan revealed no uptake in the lesions and therefore, following MDT discussion, SB has been referred for systemic chemotherapy.
Neurofibromatosis type 1 was first described by Von Ricklinghausen in 1882, and the various phenotypes were documented 1956. It is an autosomal dominant disorder affecting 1 in 3500 people, characterised by the presence of multiple café au lait spots, skinfold freckling, and neurofibromas amongst other features. Endocrine neoplasia is rare in association with NF1 but phaeochromocytoma, gastrointestinal neuroendocrine tumours, medullary thyroid cancer, and hyperparathyroidism are described. Of these, phaeochromocytoma has the highest frequency at 15%. Additionally, optic gliomas seen in 15% of children with NF1 are associated with precocious puberty. The diagnosis of NF1 will be discussed based on current guidelines, along with a review of the literature documenting NF1 related endocrine neoplasia. The clinical management of NF 1 should include screening for endocrine neoplasia and pheochromocytomas and NF1 should be considered in the differential diagnosis for patients presenting with these neoplasms.