A Man with Abdominal Pain: Enough Evidence for Surgery?

[摘要] A 53-year-old man experienced periodic abdominal discomfort and a decreased capacity to work. His primary physician ordered a broad range of laboratory tests as part of the initial workup. The results revealed a greatly increased adrenocorticotropic hormone (ACTH)7 concentration of >1250 pg/mL (>278 pmol/L) [reference interval <46 pg/mL (<10.2 pmol/L)]. Cortisol was within the reference interval. Repeat measurements 4 weeks later confirmed the increased ACTH. Investigators rapidly excluded 2 well-known conditions associated with increased ACTH concentrations: Cushing disease (ACTH-producing pituitary tumor) and Addison disease (adrenal insufficiency) (1, 2). An investigation for an ectopic source of ACTH was begun (3).Over the next 18 months, the patient underwent a plethora of imaging studies. A series of conventional studies failed to provide an explanation for the increased ACTH, and ultimately a positron emission tomography/computed tomography (PET/CT) scan using a relatively new radiotracer, 68Ga-labeled 1,4,7,10-tetraazacyclododecane- N,N ′, N ′′, N ′′′ - tetraacetic acid-d-Phe1-Tyr3-octreotide (68Ga-DOTATOC), was performed (4). A 3.3-cm area in the head of the pancreas with an increased uptake of radiotracer was observed (Fig. 1). In light of the persistently increased ACTH concentration, this finding raised the suspicion of a pancreatic ACTH-secreting neuroendocrine tumor, a rare ectopic source of ACTH (3). Although MRI and conventional CT evaluations did not confirm the presence of a tumor, the patient was offered immediate surgical treatment. The patient declined the offer and subsequently sought second and third opinions at medical facilities in 2 different countries. In both facilities, a neuroendocrine tumor was deemed the likely cause of his problems, and surgery was again suggested. Wishing minimally invasive treatment, the patient contacted the Interventional Centre at our hospital, which offers laparoscopic resection of the pancreas.Fig. 1. 68Ga-DOTATOC PET/CT scan from June 2009 showing increased uptake of radiotracer in the processus uncinatus of the pancreas (arrow), with a maximum standardized uptake value (SUVmax) of 9. Physiological accumulation in the liver (L) and kidneys (K).### QUESTIONS TO CONSIDER1. Why …

[学科分类] 过敏症与临床免疫学