Near total replacement of the pancreas with cysts in a patient with Von Hippel Lindau DiseaseAbstract: Von Hippel Lindau (VHL) disease can affect various organ systems of the body and is associated with tumors and visceral cysts. Lesions of the pancreas are fairly common leading to the occurrence of simple cysts, serous cystadenoma or solid tumors. We present a rare case of a 35 year old woman previously diagnosed with VHL disease whose pancreas on endoscopic ultrasound was found to be replaced by cysts of varying sizes with normal pancreatic tissues and duct not being identified.IntroductionVHL is an autosomal dominant genetic disorder with a birth incidence prevalence of about 1 in 36,000 live births.(1) It can manifest with as various benign or malignant tumors involving the central nervous system (CNS) and / or gastrointestinal system.(2) Similarly the pancreatic lesions in VHL, which are commofoundn in 60% of the patients with VHL disease, can range from a simple cyst to serous cystadenoma or to neuroendocrine tumor (NET).(3) These lesions are usually asymptomatic as in our patientpatients with VHL disease.(4) The literature review of the pancreatic manifestations of the VHL disease do mention the occurrence of multiple cysts in pancreas but the replacement of the entire pancreas due to cysts in VHL is rare.Case ReportA 35 year old South-Asian womaen presented to our outpatient department as with her recent MRI showinged increasing size of her previously documented pancreatic cysts. It was which were first identified on an abdominal ultrasound 2 years prior. She denied any symptoms including nausea, vomiting, abdominal pain, diarrhea or any previous episodes of pancreatitis. She had no family history of VHL or isolated pancreatic cysts. Physical examination was unremarkable. Her past surgical history was significant for 2two brain surgeries for hemangioblastoma. She had no signs or symptoms of pancreatic exocrine insufficiency. She had never smoked nor consumed alcohol. We performed an outpatient endoscopic ultrasound in outpatient setting that showed revealed complete replacement of the pancreatic parenchyma completely replaced by cysts, with the largest cyst measuring 3 c27.1 mm in diameter (Fig. 1 – 3). There were several smaller cysts and some cysts with septations. No mural nodules or thickened walls were identified. No pancreatic tissue or ducts were identified. No solid masses were seenvisible. The CBD could not be identified as it was obscured by pancreatic cysts. The spleen and kidney were normal in appearance.DiscussionVHL is an autosomal dominant disease caused by a mutation of the tumor suppressor gene located on the chromosome 3p25, leading to the faulty production of the VHL protein. This leads to the excessive accumulation of the hypoxia-inducible factor-1? leading to the uncontrolled cell division and development of the cysts and tumors.(5) Overall 39% patientsof patients with VHL disease can have CNS hemangioblastomas as their initial manifestation as in our patient.(6) Lesions can occur in various organ systems of the body and it is not restricted to the pancreas and the CNS. Pancreatic lesions in VHL are common and can be subdivided into 2 categories as solid and cystic lesions.(7) Solid tumors are usually non-functioning NETs and have a lower malignant potential compared to the sporadic NETs.(7) Cystic lesions like simple pancreatic cyst and serous cystadenomas are usually asymptomatic (4). The pancreatic cysts occurs around the mean age of 33 years.(8) Even patients with multiple pancreatic cysts may not have any symptoms and do may not need any surgical treatment.(9) Rarely, pancreatic cysts in VHL disease can cause symptoms due to biliary obstruction requiring leading to surgical interventions.(10) There have also been reports of acute pancreatitis due to obstruction caused by the cysts in VHL disease.(11) For patients with abdominal symptoms due to VHL, EUS can be useful.(12) Replacement of the entire pancreas with the cysts is not very common especially in the absence of any malignancy, and there haves been only very fewone case reports in our literature search previously which documentedts this finding in VHL disease with an endoscopic ultrasound.(13, 14) MainlyRarely, patients with large neuroendocrine tumors can become symptomatic especially due to secretion of the peptides and require resection due to the risk of metastasis.(4, 15) As far as the treatment is concerned, observation is recommended for the benign cysts and sometimes surgery for the larger NET.(16) Abdominal imaging with ultrasound and MRI is recommended at least every other year for early detection of tumors in the kidneys, pancreas, and adrenals.(17) In the case of a new solid lesion in the pancreas or increase in size of a cystic lesion, especially in association with concerning features, like a mural nodule, repeat EUS with possible fine needle aspiration may be helpful to aid in diagnosis.This case report contributes to the medical literature regarding the unique pancreatic manifestations of the VHL disease and careful follow up is recommended for these lesions to aid in the early detection of malignancy.