von Hippel-Lindau disease: genetic, clinical, and imaging features

Early identification of patients with von Hippel-Lindau disease at risk for pheochromocytoma

von Hippel-Lindau disease (VHL) is an autosomal dominant familial syndrome that predisposes to the formation of tumors in multiple organ systems, including adrenal and extra-adrenal pheochromocytomas. However, fewer than 30% of VHL families develop pheochromocytomas. In recent years, this clinical heterogeneity has been correlated with missense mutations. The VHL patient requires vigilant, lifelong biochemical and radiographic screening for pheochromocytoma. Half of VHL pheochromocytomas present bilaterally, and there is a high incidence of recurrence after surgery. Because of the morbidity of bilateral total adrenalectomy with subsequent steroid replacement therapy, the recent therapeutic trend has been toward observation and minimally invasive adrenal-sparing procedures.

Intraoperative ultrasound during renal parenchymal sparing surgery for hereditary renal cancers: a 10-year experience

PURPOSE

We review our 10-year experience with intraoperative ultrasound during renal parenchymal sparing surgery in patients with hereditary renal cancers.

MATERIALS AND METHODS

Between 1991 and 2000, 68 nephron sparing procedures were performed on 26 women and 27 men, all but 1 of whom had a hereditary predisposition to renal cancer, for example von Hippel-Lindau, hereditary papillary renal cancer. Intraoperative ultrasound was performed after the surgeon removed all visible or palpable lesions. High frequency transducers (7 MHz.) and color Doppler were used in all cases. Lesions were characterized as simple cysts, complex cysts or solid masses, and were recorded on a map.

RESULTS

A total of 935 lesions (mean 12.8 lesions per kidney) were removed in 68 nephron sparing operations performed on 53 patients. Of these lesions 870 were removed without while 65 required intraoperative ultrasound. In 17 of 68 (25%) procedures intraoperative ultrasound identified renal cancers that were not detectable by the surgeon. Mean tumor size of ultrasound detected lesions was 1.0 cm. (range 2 mm. to 4 cm.). Of the 32 cystic lesions identified by intraoperative ultrasound 5 contained renal carcinoma, and 29 of the 33 solid renal masses were renal cell carcinomas. During reoperations ultrasound enabled the surface of the kidney to be evaluated even when it was inaccessible due to scar tissue or adherent perinephric fat.

CONCLUSIONS

Intraoperative ultrasound can be performed after all visible lesions have been removed and identifies additional tumors in 25% of patients with hereditary renal cancer, thus ensuring that as many tumors as possible have been removed during renal parenchymal sparing surgery.

Hemangioblastomas of the central nervous system in von Hippel-Lindau syndrome and sporadic disease

OBJECTIVE

The presentation, screening, management, and clinical outcomes of patients who presented to our institution from 1973 to 1999 with central nervous system (CNS) hemangioblastomas in von Hippel-Lindau (VHL) syndrome and sporadic disease were analyzed.

METHODS

The surgical pathology database of our institution was searched to identify all patients with histologically verified CNS hemangioblastomas occurring from 1973 to 1999. The medical, radiological, surgical, pathological, and autopsy records from these patients were reviewed retrospectively and statistically analyzed.

RESULTS

Forty patients (21 males and 19 females) presented with CNS hemangioblastomas. Twenty-five patients (62%) harbored sporadic hemangioblastomas. Fifteen patients (38%) had VHL syndrome. These 40 patients presented with 61 hemangioblastomas (8 patients had multiple lesions). Ten patients (25%) harbored spinal cord hemangioblastomas (5 patients had multiple lesions). Patients with VHL disease tended to present with neurological symptoms and signs at a younger age than patients with sporadic disease (P = 0.09), to present with multiple lesions (53%), and to develop new lesions (rate, 1 lesion/2.1 yr). Hemangioblastomas of the spinal cord were more prevalent in patients with VHL syndrome (P = 0.024). Neuroradiological screening of patients with VHL syndrome allowed identification of more than 75% of new lesions before they became symptomatic. Sixty-six surgical procedures were performed (12 patients required multiple operations). Six patients with VHL syndrome required surgery for new lesions. Surgical complications occurred in six patients (15%). Symptom resolution or arrest of progression at 1 year was documented in 88% of patients. Recurrence of symptoms from partially resected lesions occurred in eight patients (20%). No deaths associated with surgery occurred. One patient with sporadic disease and one patient with VHL syndrome (5%) died as a result of late medical complications from CNS hemangioblastomas.

CONCLUSION

Surgical outcomes for patients with CNS hemangioblastomas are favorable. However, management of hemangioblastomas is a more difficult and prolonged endeavor for patients with VHL syndrome. In patients with VHL syndrome, neuroradiological screening allows identification of lesions before they become symptomatic. Because patients with VHL syndrome are at risk for development of new lesions, they require lifelong follow-up.

[Epidural anesthesia for Cesarean section in a patient with von Hippel-Lindau syndrome]

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder with variable penetrance. It is mainly characterized by haemangioblastomas of the retina and central nervous system. Because of physiological effects of uterine contractions, labour and spontaneous vaginal delivery increase the risk of disrupting central nervous system haemangiblastomas. We report the case of a 28-year-old woman with an history of VHL disease who had an epidural anaesthesia for labour and for Caesarean section performed because of failure to progress and of fetal distress. The overall maternal and neonatal outcomes were excellent.

Clinical and genetic analysis of patients with pancreatic neuroendocrine tumors associated with von Hippel-Lindau disease

BACKGROUND

Patients with von Hippel-Lindau disease (VHL) may develop pancreatic neuroendocrine tumors (PNETs), which can behave in a malignant fashion. We prospectively evaluated size criteria for resection of lesions and the role of genotype/phenotype analysis of germline VHL mutations in predicting clinical course.

METHODS

From December 1988 through December 1999 we screened 389 patients with VHL. The diagnosis of PNET was made by pathologic analysis of tissues or by radiographic appearance. Germline mutations were determined by quantitative Southern blotting, fluorescence in situ hybridization and complete gene sequencing.

RESULTS

Forty-four patients with PNETs have been identified; 25 have undergone surgical resection, 5 had metastatic disease, and 14 are being monitored. No patient who has undergone resection based on tumor size criteria has developed metastases. Patients with PNETs were more likely to have missense mutations (58%), and 4 of 5 patients (80%) with metastatic disease had mutations in exon 3 compared with 18 of 39 (46%) patients without metastatic disease.

CONCLUSIONS

Imaging for detection and surgical resection based on size criteria have resulted in the successful management of VHL patients with PNETs. Analysis of germline mutations may help identify patients at risk for PNET and which patients may benefit from surgical intervention.

Pheochromocytoma: inherited associations, bilaterality, and cortex preservation

BACKGROUND

Hereditary pheochromocytoma (HP) is characterized by early onset, bilateral adrenal involvement, low malignancy rate, and genetic linkage with certain familial syndromes. This retrospective review is intended to show the high yield of surveillance, predictable bilaterality, and the challenge of cortex-sparing adrenalectomy.

METHODS

From 1964 to 1999, 32 patients with HP were treated at a single institution and followed for a mean of 7 years. There were 15 cases of multiple endocrine neoplasia type 2A (MEN 2A), 12 cases of von Hippel-Lindau (VHL) disease, 3 cases of von Recklinghausen's disease (VRD), and 2 cases of familial pheochromocytoma. Twenty-four of 32 patients underwent bilateral adrenalectomy (9 metachronous). Subtotal resection with orthotopic cortex preservation was performed in 5 patients, and heterotopic autografting was performed in 14 patients.

RESULTS

Pheochromocytoma was the first manifestation in 50% of patients with VHL disease and in 27% of patients with MEN 2A. Surveillance uncovered medullary thyroid cancer in 5 of 15 patients with MEN 2A and hemangioblastomas, renal cell carcinoma, and islet cell tumors in 7 of 15 patients with VHL disease and VRD. HP was bilateral in 24 of 32 patients (14/15 in patients with MEN 2A, 7/12 in patients with VHL disease, 2/3 in patients with VRD, and 1/2 in patients with familial pheochromocytoma). In 9 cases of metachronous adrenalectomy, the mean interval was 67 months (range, 9-156 months). Three of 5 patients who underwent orthotopic preservation of the adrenal cortex experienced recurrence compared with 0 of 14 patients with heterotopic autotransplantation of cortical tissue.

CONCLUSIONS

Pheochromocytoma frequently heralds coexisting silent VHL disease or MEN-2, mandating surveillance for inherited associations. The long interval of metachronous pheochromocytoma argues against prophylactic removal of the contralateral "normal" adrenal gland. Total adrenalectomy and heterotopic autotransplantation of medulla-free cortex may diminish the need for lifelong steroid substitution and eliminates recurrence.

Histopathology and molecular genetics of multiple cysts and microcystic (serous) adenomas of the pancreas in von Hippel-Lindau patients

Microcystic adenoma and cysts of the pancreas occur sporadically or as a part of von Hippel-Lindau (VHL) disease. The pathology of pancreatic cystic disease in VHL patients has not been well characterized. Furthermore, it is presently unknown whether the alteration of the VHL gene is responsible for the development of the entire spectrum of pancreatic serous cystic lesions. We performed a histopathological analysis of 21 cysts and 98 microcystic adenomas in nine VHL patients with a known germline mutation. In addition, PCR-amplified DNA from 27 pancreatic cystic lesions in three informative patients was studied for allelic deletions with polymorphic markers spanning the VHL gene locus. In all patients, pancreatic lesions were multiple: 21 benign serous cysts, 63 microscopic microcystic adenomas (size <0.4 cm), and 35 macroscopic microcystic adenomas (size >0.5 cm). The average number of lesions per patient was 2.1 benign cysts (range, 0-8), 7.7 (1-37) microscopic microcystic adenomas, and 3 (0-21) macroscopic microcystic adenomas. All lesions showed similar histology and contained prominent fibrous stroma, clear and/or amphophilic, glycogen-rich epithelial cells, endothelial and smooth muscle cells. VHL deletions were detected in all types of pancreatic cystic lesions. The presence of VHL gene allelic deletions in the spectrum of multifocal pancreatic cystic lesions provides direct molecular evidence of their neoplastic nature and integral association with VHL disease. The histopathological and molecular data establish a serous cyst-microcystic adenoma continuum in the development of pancreatic cystic neoplasia in VHL disease.

Pancreatic involvement in von Hippel-Lindau disease. The Groupe Francophone d'Etude de la Maladie de von Hippel-Lindau

BACKGROUND & AIMS

Pancreatic involvement in von Hippel-Lindau (VHL) disease, a genetic disorder with a dominant mode of inheritance affecting various organs, has rarely been studied. We assessed the prevalence, type of lesions, natural history, and impact of pancreatic involvement in patients with VHL.

METHODS

A total of 158 consecutive patients from 94 families with VHL disease were studied in a prospective French collaborative study. All patients underwent systematic screening for VHL lesions, including computerized tomography (CT) scanning of the pancreas reviewed by an experienced radiologist. Clinical data, investigations, and treatments performed were also reviewed.

RESULTS

Pancreatic involvement was observed in 122 patients (77.2%) and included true cysts (91.1%), serous cystadenomas (12.3%), neuroendocrine tumors (12.3%), or combined lesions (11.5%). The pancreas was the only organ affected in 7.6% of patients. Patients with pancreatic lesions had fewer pheochromocytomas than those without (14/122 vs. 16/36; P<0.0001), and patients with neuroendocrine pancreatic tumors had renal involvement less often than those without (8/99 vs. 6/20; P = 0.013). None of the patients with neuroendocrine tumors had symptoms of hormonal hypersecretion. Pancreatic lesions evolved in half of patients but required specific treatment in only 10 (8.2%) when they were symptomatic or for the resection of large neuroendocrine tumors.

CONCLUSIONS

Pancreatic involvement is seen in most patients with VHL disease. Although symptoms are rare, specific treatment of pancreatic lesions is required in selected patients, mainly those with neuroendocrine tumors.

Malignant pheochromocytoma with progressive paraparesis in von Hippel-Lindau disease

Pheochromocytomas are a feature of the von Hippel-Lindau disease spectrum, a multisystem disorder of autosomal dominant inheritance. Pheochromocytomas are, however, observed during life with a lower frequency than other features of this disease, such as retinal angiomas, haemangioblastomas of the CNS, and renal carcinomas. We present the highly unusual case of a patient who required an emergency operation for an intradural extramedullary thoracic tumour which was clinically suggestive initially of neurinoma. We present evidence from NMR, histological and isotope scan investigations of this being a pheochromocytoma metastasis and of an additional right-sided paraganglioma at the same height. A detailed history revealed that this patient had suffered from four other pheochromocytomas and two other paragangliomas, in addition to retinal angiomatosis of von Hippel-Lindau disease. This case is extraordinary due to (i) the unusual site of the metastasis, (ii) the neurological requirement for an emergency operation of pheochromocytoma, (iii) metastasis of pheochromocytoma in von Hippel-Lindau disease (only eight previous cases), and (iv) the number of recurrent pheochromocytomas. It clearly demonstrates the necessity for frequent and life-long follow-up in von Hippel-Lindau disease.

von Hippel-Lindau syndrome: target for anti-vascular endothelial growth factor (VEGF) receptor therapy

von Hippel-Lindau (VHL) syndrome is a familial cancer syndrome caused by germline mutations in the VHL tumor suppressor gene. Mutations in the VHL gene result in the constitutive stabilization of transcription factors hypoxia-inducible factors 1alpha and 2alpha, which bind to specific enhancer elements in the vascular endothelial growth factor (VEGF) gene and stimulate angiogenesis. This increase in angiogenesis under normoxic conditions in key target organs such as the brain, kidney, and eye leads to high morbidity and reduced life expectancy. Drugs designed to block the VEGF signaling pathway may prevent the long-term complications of the disease. To test this hypothesis, a clinical study was initiated to evaluate the effect of the VEGF tyrosine kinase receptor inhibitor SU5416 in patients with VHL syndrome. Preliminary data on SU5416 indicate that it is well tolerated when administered chronically in such patients. However, since little is known about the long-term use of such inhibitors, patients will need careful monitoring. Data obtained from monitoring these patients will provide valuable information for adjuvant treatment trials in cancer patients.

[Haemangioblastomas: clinical, epidemiological and pathological findings in 14 cases]

We report the clinical, epidemiological and pathological findings of 14 patients with haemangioblastoma. Sixty-four percent occurred in males, with ages ranging from 16 to 60 years, with an average of 34, 4 years. Most of the tumours were confined to the cerebellum (n=9). The most frequent symptoms were headache (n=7) and dizziness (n=7), with a mean duration of 70 days. Von Hippel-Lindau syndrome (vHL) was diagnosed in 3 patients. Eleven patients were submitted to total surgical removal and in 3 the tumour was partially resected. A relapse rate of 28% in 3 years of follow-up was found. The patients with vHL showed recurrence in 66% of the cases. These findings corroborate those in current medical literature, showing an increased morbidity of this tumor when associated with vHL.

Renal cell carcinomas in von Hippel-Lindau disease; tumor detection and management

Twenty-seven renal cell carcinomas (RCCs) found in one family affected with von Hippel-Lindau disease were examined using ultrasound (US), CT, MRI and angiography. The sensitivity of the tumor detection using different imaging modalities was evaluated by macroscopic pathology (solid or cystic) and size (exceeding 2cm in diameter or not). In 18 of the RCC's exceeding 2cm in diameter (eight solid and ten cystic), all lesions were detected on US, CT, and MRI. However, on angiography, solid RCCs were detected in 88%, and cystic RCCs were detected in 60%. In nine RCCs less than 2cm in diameter (seven solid and two cystic), solid RCCs were detected in 86% on US, 86% on CT, 80% on MRI, and 43% on angiography, but cystic RCCs were detected in 50% on only CT and MRI. From the pathologic correlation, even renal simple cystic lesions in VHL are considered premalignant lesions and they had better be removed if the residual renal function after surgery is preserved. In case of the observation, they should be followed carefully using thin slice thickness dynamic CT to discover the wall irregularity, septation and irregular contour.

von Hippel-Lindau disease

An autosomal dominant tumor predisposition syndrome, von Hippel-Lindau disease (VHL) is characterized by the presence of benign and malignant tumors. Hallmark lesions include retinal angiomas, hemangioblastomas of the cerebellum and spinal cord, and renal cell carcinomas. Affected persons may also have angiomatous or cystic lesions of the kidneys, pancreas, and epididymis, as well as adrenal pheochromocytomas. In this article, we discuss the clinical features and diagnostic criteria for this clinically underdiagnosed condition. An update on recent findings regarding the molecular genetics of VHL is provided, including a discussion of the evolving understanding of genotype-phenotype correlations. Understanding the molecular and functional aspects of this condition will lead to the development of strategies for the management and treatment of inherited and sporadic VHL-associated tumors.

Intra-cranial manifestations of the neurocutaneous syndromes

The neurocutaneous syndromes or phakomatoses are a heterogeneous group of congenital disorders primarily involving structures derived from the embryological neuroectoderm. All of the syndromes involve the central nervous system (CNS). Peripheral nerves, skin and other organ systems may also be involved. Twenty to 30 disorders are now classified as neurocutaneous syndromes. This article reviews the intra-cranial imaging features of some of the commonest.

Mosaicism in von Hippel-Lindau disease: lessons from kindreds with germline mutations identified in offspring with mosaic parents

von Hippel-Lindau disease (VHL [MIM 193300]) is a heritable autosomal dominant multiple-neoplastic disorder with high penetrance. It is characterized by brain and spinal-cord hemangioblastomas, retinal angiomas, clear-cell renal carcinoma, neuroendocrine tumors and cysts of the pancreas, pheochromocytomas, endolymphatic-sac tumors, and papillary cystadenomas of the epididymis and broad ligament. Although most index cases have a positive family history of VHL, some do not and may represent de novo cases. Cases without a family history of VHL may or may not have a germline mutation in their VHL tumor-suppressor gene. We present two cases of VHL mosaicism. In each of two families, standard testing methods (Southern blot analysis and direct sequencing) identified the germline mutation in the VHL gene of the offspring, but not in their clinically affected parent. Additional methods of analysis of the affected parents' blood detected the VHL-gene mutation in a portion of their peripheral blood lymphocytes. In one case, detection of the deleted allele was by FISH, and, in the second case, the 3-bp deletion was detected by conformational sensitive gel electrophoresis and DNA sequencing of cloned genomic DNA. Mosaicism in VHL is important to search for and recognize when an individual without a family history of VHL has VHL. Patients diagnosed without family histories of the disease have been reported in as many as 23% of kindreds with VHL. Identification of individuals potentially mosaic for VHL will affect counseling of families, and these individuals should themselves be included in clinical screening programs for occult disease.

Clinical and genetic characterization of pheochromocytoma in von Hippel-Lindau families: comparison with sporadic pheochromocytoma gives insight into natural history of pheochromocytoma

PURPOSE

Families with von Hippel-Lindau disease have variable risk of pheochromocytoma. Patients with von Hippel-Lindau disease and pheochromocytoma identified by screening can have no characteristic signs or symptoms. Families with von Hippel-Lindau disease were screened and followed to describe the natural history of von Hippel-Lindau pheochromocytoma, and to correlate these findings with von Hippel-Lindau germline mutation.

MATERIALS AND METHODS

Between 1988 and 1997, 246 individuals with von Hippel-Lindau disease were identified (von Hippel-Lindau group). Between August 1990 and June 1997, 26 consecutive patients with sporadic pheochromocytoma were evaluated (sporadic group).

RESULTS

A total of 64 patients with von Hippel-Lindau disease had manifestations of pheochromocytoma, including 33 newly diagnosed during screening at the National Institutes of Health and 31 previously treated (93 adrenal and 13 extra-adrenal pheochromocytomas). Germline von Hippel-Lindau gene missense mutation was associated with extra-adrenal pheochromocytoma, younger age at presentation and the only patient with metastases. Of the 33 newly diagnosed patients with von Hippel-Lindau disease 4 had pheochromocytoma 2 times (37 pheochromocytomas) during followup. Of these pheochromocytomas 35% (13 of 37) were associated with no symptoms, normal blood pressure and normal catecholamine testing. Comparison of urinary catecholamines in the von Hippel-Lindau and sporadic groups demonstrated increased epinephrine, metanephrines and vanillylmandelic acid in the sporadic group. Analysis of urinary catecholamine excretion in the von Hippel-Lindau and sporadic groups together demonstrated a correlation between tumor size, and urinary metanephrines, vanillylmandelic acid, norepinephrine, epinephrine and dopamine. In 12 patients without signs or symptoms of pheochromocytoma 17 newly diagnosed pheochromocytomas were followed for a median of 34.5 months without morbidity. Median tumor doubling time was 17 months.

CONCLUSIONS

Von Hippel-Lindau gene missense mutation correlated with the risk of pheochromocytoma in patients with von Hippel-Lindau disease. These findings support a von Hippel-Lindau disease clinical classification, wherein some families are at high risk for manifestations of pheochromocytoma. Von Hippel-Lindau disease pheochromocytomas identified by screening were smaller and less functional than sporadic pheochromocytomas.

[Cystic lesions of the pancreas]

Most cystic lesions of the pancreas are pseudocysts caused by acute or chronic pancreatitis. Congenital cysts are rare and may occur in congenital syndromes like von Hippel-Lindau syndrome. Cystic tumors of the pancreas may be difficult to distinguish clinically; however, because of their malignant potential, in particular in cases of mucinous types, diagnostic verification is crucial. Hence, in all cases of cystic lesions of the pancreas, which are not a sequela of an etiological confirmed acute or chronic pancreatitis, a cystic neoplasm must be ruled out. Differential diagnosis may be difficult even with ultrasonography, computertomography, endoscopic retrograde cholangiopancreatography and serum analyses; endoscopic ultrasound, magnetic resonance tomography and analysis of the cyst content may be of particular value. The therapeutic approach for pseudocysts is now well established and guided by symptoms and complications. If a cystic neoplasm is suspected, surgical resection of the complete lesion is warranted.

CONCLUSION

The most important differential diagnosis in all cystic lesions of the pancreas with atypical presentation includes a cystic neoplasm. Therefore complete resection is indicated whenever the suspicion cannot be ruled out.

Imaging features of posterior fossa neoplasms in children and adults

Masses in the posterior fossa may be divided into extra-axial and intra-axial lesions. Because of its multiplanar capabilities, improved soft-tissue resolution and contrast, and the absence of scanning artifacts related to the osseous skull base, which are frequently present on CT, MRI is the imaging modality of choice in evaluating lesions arising in the posterior fossa. It is the best means of critically localizing lesions and determining the extent of disease. Analysis of the signal characteristics of a lesion on multiple different imaging sequences (T1-weighted, T2-weighted, and enhanced images) may provide information about the tissue constituents within a mass/neoplasm, such as the presence of cellularity, necrosis, and hemorrhage. MRI is also useful in guiding localization for brain tumor biopsies and assists in planning radiation therapy. However, CT also plays an important role. CT is frequently the first imaging study performed in patients with posterior fossa masses who often present with nausea, vomitting, ataxia, and other signs of increased intracranial pressure. It is a quick, available, and relatively inexpensive study to assess neurological emergencies including hydrocephalus, hemorrhage, and herniation syndromes. In addition, it frequently provides complimentary information, such as the presence of calcification or bony remodeling (osteosclerosis or osteolysis), which MRI is less sensitive in detecting.

Neurology and the kidney

Renal failure is relatively common, but except in association with spina bifida or paraplegia it is unlikely to occur as a result of disease of the CNS. Renal failure, however, commonly affects the nervous system. The effects of kidney failure on the nervous system are more pronounced when failure is acute. In addition to the important problems related to renal failure there are both acquired and genetically determined diseases which may affect the kidney and the brain. Those acquired diseases include the vasculitides, the paraproteinaemias, and various granulomatous conditions (considered in other chapters of Neurology and Medicine). In two of the most commonly encountered genetically determined diseases, Von Hippel-Lindau disease and polycystic kidney disease, location of pathogenic mutations will provide improved screening programmes and, possibly, allow therapeutic intervention. Uraemia may affect both the central and peripheral nervous systems. Whereas the clinical features of uraemia are well documented, the pathophysiology is less well understood and probably multifactorial. Uraemic encephalopathy, which classically fluctuates, is associated with problems in cognition and memory and may progress to delirium, convulsions, and coma. The encephalopathy may initially worsen with periods of dialysis and almost certainly relates to altered metabolic states in association with ionic changes and possibly impaired synaptic function. Renal failure may affect the peripheral nervous system, resulting in a neuropathy which shows a predilection for large diameter axons. This may be reversed by dialysis and transplantation. The myopathy seen in renal failure, often associated with bone pain and tenderness, is similar to that encountered in primary hyperparathyroidism and osteomalacia. Dialysis itself is associated with neurological syndromes including the dysequilibrium syndrome, subdural haematoma, and Wernicke's encephalopathy. Dialysis dementia, which was prevalent during the 1970s, has reduced in frequency with the use of aluminium free dialysate. With the introduction of transplantation and the concomitant use of powerful immunosuppressive drugs, the pattern of neurological problems encountered in renal replacement therapy has shifted. Five per cent of patients develop nerve injuries during renal transplantation, and up to 40% of patients experience neurological side effects from cyclosporine. Furthermore, CNS infections, often fungal in type, have been reported in up to 45% of transplant patients coming to postmortem. The nature of the involvement of neurologists with their nephrology colleagues is therefore evolving.

Pancreatic neuroendocrine tumors associated with von Hippel Lindau disease: diagnostic and management recommendations

BACKGROUND

von Hippel Lindau disease (VHL) is an inherited syndrome characterized by tumors of the kidney, adrenal, central nervous system, and pancreas. The incidence and natural history of pancreatic neuroendocrine tumors occurring in VHL are not known.

METHODS

From December 1988 through November 1997, 256 patients with VHL were screened with imaging studies, and these data were reviewed from a prospective database.

RESULTS

Thirty (12%) of 256 patients had solid pancreatic lesions consistent with neuroendocrine tumors. Fourteen patients underwent resection, and 4 with metastases on imaging studies underwent biopsy only. Of the 14 patients who underwent resection, 11 remain free of disease, 2 have experienced recurrence, and 1 has died of unrelated causes (mean follow-up, 25 months; range, 3 to 73 months). The size of the primary tumor (median, 5 cm; range, 3 to 8 cm) in patients with liver metastases was significantly larger than the size of the primary tumor (median, 2 cm; range, 1 to 5 cm) in patients without liver metastases (P = .0013).

CONCLUSIONS

Solid pancreatic lesions were detected in 12% of patients with VHL. Larger primary tumors were associated with liver metastases. Pancreatic imaging to identify neuroendocrine tumors and resection when they reach 2 to 3 cm may prevent the development of hepatic metastases.

Multifocal serous cystadenoma of the pancreas. A case report and review of the literature

Serous cystadenoma of the pancreas is usually unifocal; multifocal tumors are rare. We report a case of multifocal serous cystadenoma of the pancreas in a 48-yr-old female complaining of general malaise. Serum tumor markers, such as CA 19-9, DUPAN-2, and Span-1, were elevated. Abdominal ultrasound (US) and computed tomography (CT) scans revealed two distinct cystic masses in the head and body of the pancreas, respectively. The patient underwent total pancreatectomy. The resected pancreas contained two discrete cystic masses in the head and body; no solid components were observed. Microscopically, the inner surfaces of the cysts were evenly lined by a single layer of low cuboidal or significantly attenuated epithelial cells containing clear cytoplasm and abundant glycogen without other morphological alterations. The histogenesis of serous cystadenoma is not clear; multicentric tumors may be helpful in understanding histogenesis.

Incidental Atypical Pheochromocytoma in Sporadic Type IIB Von Hippel-Lindau Disease

OBJECTIVE

To describe the features of an incidentally discovered atypical pheochromocytoma in an asymptomatic patient with normal blood pressure and the de novo appearance of sporadic type IIB von Hippel-Lindau (VHL) disease.

METHODS

We review the clinical manifestations, radiographic findings, and unusual features of a large, atypical pheochromocytoma diagnosed in a patient with the rare type IIB phenotype of VHL disease.

RESULTS

A 46-year-old man, who sought medical assistance in the emergency department after a motorcycle accident, had an abdominal roentgenogram that revealed extensive left suprarenal calcification. Computed tomography of the abdomen demonstrated a densely calcified left adrenal mass, bilateral renal cysts, and pancreatic calcifications. The patient was normotensive and asymptomatic and had no history of hypertension. He had undergone resection of a cerebellar hemangioblastoma at age 36 years and a partial left nephrectomy for a renal cyst at age 7 years. Routine biochemical screening demonstrated increased urinary vanillylmandelic acid and normetanephrine levels as well as an elevated plasma norepinephrine level. The adrenal mass was notable for the absence of increased signal intensity on T2-weighted magnetic resonance images. The patient was diagnosed with the type IIB phenotype of VHL disease and underwent resection of a 10.5-cm, 124-g benign pheochromocytoma.

CONCLUSION

Our case emphasizes the importance of recognizing that pheochromocytoma may occur in association with sporadic VHL disease, that not all pheochromocytomas have an increased signal intensity on T2-weighted magnetic resonance images, and that routine biochemical testing for pheochromocytoma is important in all patients with an adrenal "incidentaloma."

Multiple neuroendocrine tumors of the pancreas in von Hippel-Lindau disease patients: histopathological and molecular genetic analysis

Although pancreatic neuroendocrine tumors (NETs) in von Hippel-Lindau (VHL) disease have been reported, their pathological features have not been characterized. In addition, it is unknown whether alterations of the VHL gene are responsible for pancreatic NET development. To evaluate NETs in VHL patients, we performed histopathological analysis of 30 pancreatic tumors in 14 patients. In addition, DNA from NETs and normal pancreatic tissue from 6 patients with documented germ-line VHL gene mutations was studied for allelic deletions of the second copy of the VHL gene by fluorescence in situ hybridization and polymerase chain reaction-based single-strand conformational polymorphism analysis. Morphologically, the tumors were characterized by solid, trabecular, and/or glandular architecture and prominent stromal collagen bands. Sixty percent of the tumors revealed at least focally clear-cell cytology. All tumors were positive for panendocrine immunohistochemistry markers (chromogranin A and/or synaptophysin); 35% of NETs demonstrated focal positivity for pancreatic polypeptide, somatostatin, insulin, and/or glucagon; and no immunostaining for pancreatic and gastrointestinal hormones was observed in 65% of tumors. Dense core neurosecretory granules were evident by electron microscopic examination, and the clear cells additionally revealed abundant intracytoplasmic lipid. All NETs that were subjected to genetic analysis showed allelic loss of the second copy of the VHL gene. We conclude that multiple, nonfunctional pancreatic NETs occur in VHL patients. Stromal collagen bands and clear-cell morphology are important histological features of VHL-associated NETs. The presence of allelic deletions of the VHL gene in pancreatic NETs provides direct molecular evidence for a role of the gene in their tumorigenesis and establishes NET as an independent tumor type of VHL disease.

Endolymphatic sac tumours

This review article surveys clinical and pathological literature on endolymphatic sac tumours (ELST) and summarizes characteristics that describe the entity. ELST are rare neuroectodermal neoplasms in the petrous bone, originating from inner ear structures. They can be encountered sporadically or in von Hippel-Lindau disease. The most prominent symptom is sensorineural deafness. Historically, nomenclature of invasive adenoid tumours in the petrous bone has been divergent, the term papillary adenocarcinoma used most frequently. Histologically, they have a follicular or papillary and adenoid pattern that can be easily confused with various other neoplastic conditions including metastatic carcinoma. It remains to be verified whether similar tumours (papillary adenocarcinomas) can originate from the middle ear. Middle ear adenomas have a similar appearance but probably originate from neural crest cells in the middle ear. ELST can express a variety of epitopes (including cytokeratin and neuroectodermal markers) which can be detected immunohistochemically. In cases in von Hippel-Lindau disease the cerebello-pontine angle should be included in routine radiological examinations to detect ELST before the tumours lead to deafness. In apparently sporadic cases of ELST, genetic testing for von Hippel-Lindau disease should be considered. Correct distinction of ELST from metastatic carcinoma prevents futile searches for unknown primary tumours.

Genotype-phenotype correlations in von Hippel-Lindau disease

A total of 146 intragenic germline mutations of the von Hippel-Lindau (VHL) gene are known and this figure is still increasing. To date, information for mutation-specific genetic counselling is insufficient, since either the total number of carriers is very low or clinical information and investigation of symptomatic and asymptomatic is incomplete. This review summarizes all known mutations and includes the centres which performed the mutation analyses and may provide further information regarding specific mutations.

Endolymphatic sac tumors: report of three cases

OBJECTIVE AND IMPORTANCE

We present three cases of endolymphatic sac tumors and review the previously published cases. Despite frequent extension to the cerebellopontine angle, these rare tumors have only recently been recognized by neurosurgeons.

CLINICAL PRESENTATION

A 26-year-old man developed a progressive hearing loss, revealing an intrapetrous retrolabyrinthine tumor on the right side. A 28-year-old woman experienced a left cerebellopontine angle syndrome, with a lytic intrapetrous mass extending into the cerebellopontine angle. A 38-year-old woman presented with an intracranial hypertension syndrome caused by a tumor of the jugular foramen.

INTERVENTION

For the first and second patients, the tumors originated from the operculum of the endolymphatic sac. Total removal was achieved, via a transpetrosal approach, in these two cases. No recurrence was detected after a 20-month follow-up period. For the third patient, the tumor originated from the distal part of the sac. Recurrence was observed 8 years after subtotal removal via a retrosigmoid route. Histological analysis revealed a papillary-cystic adenocarcinomatous pattern in all cases, without features of aggressiveness.

CONCLUSION

Endolymphatic sac tumors are locally invasive neoplasms characterized by bipolar intrapetrous and posterior fossa involvement. The anatomic complexity of the endolymphatic sac may explain the distinct patterns of extension of these tumors. Early radical surgery is related to good outcomes.

Concurrent Pheochromocytoma, Paraganglioma, Papillary Thyroid Carcinoma, and Desmoid Tumor: A Case Report with Analyses at the Molecular Level

Reports on the association of papillary thyroid carcinoma with paraganglionic or desmoid tumors have appeared infrequently. The former setting usually affects middle-aged females; the latter is typical of familial adenomatous polyposis. We report the case of a 69-yr-old man in whom two abdominal masses had been instrumentally detected following an access of abdominal pain. Save for a moderate hypertension, he was asymptomatic and an impalpable thyroid nodule was detected by ultrasonography. A high urinary noradrenaline output and cytology of the masses raised the suspicion of pheochromocytoma. At laparotomy, an adrenal pheochromocytoma and a paracaval paraganglioma were excised. Subsequently, hemithyroidectomy was performed, and histopathology revealed papillary microcarcinoma. A nodule of desmoid tumor was also removed from the abdominal wall. An analysis of RET, APC, and TP53 gene mutations, and of RET and NTRK1 gene rearrangements, yielded negative results. No in vitro transforming activity was detected in the tumor DNA when assayed in transfection experiments. The lack of a consistent family history also made unlikely the possibility of identifying the putative germline defect by linkage analyses. Should this unusual aggregation of tumors represent a new entity, a number of genetic alterations have now been excluded.

Pancreatic cystic manifestations in von Hippel-Lindau disease

CONCLUSION

In view of the frequent absence of symptoms related to pancreatic lesions, screening tests for VHL should always include assessment of the pancreas and, considering the frequency of polycystic manifestations, VHL should always be borne in mind in the differential diagnosis of multiple pancreatic cysts, especially when occurring in young patients and in the absence of a positive history of pancreatic disease.

BACKGROUND

Von Hippel-Lindau disease (VHL) is a hereditary disease transmitted with an autosomal dominant character and characterized by hemangioblastomas of the central nervous system and retina, renal tumors and cysts, and pheochromocytoma. Pancreatic manifestations of VHL are reported in the literature with incidences ranging from 16 to 29% of cases and consist mainly in cystadenomas of the serous type and in multiple cystic lesions, often with complete replacement of the gland.

METHODS AND RESULTS

We report five cases of VHL with a polycystic pancreas as the main or only manifestation, all devoid of symptoms related to involvement of the pancreas, who were referred to our Pancreatic Surgery center with diagnoses of multiple pancreatic pseudocysts of undefined origin.

Current concepts and controversies in imaging of renal cystic diseases

Renal cystic disease compromises a diverse group of inherited and acquired entities. This article reviews the clinical, pathologic, and radiologic findings of eight renal cystic diseases. For each entity, the current concepts of pathogenesis and pathophysiology are discussed. When appropriate, controversies concerning terminology, management, and malignant potentials are addressed. Renal cystic diseases that are discussed include autosomal dominant and autosomal recessive polycystic kidney disease, medullary sponge kidney, medullary cystic disease, multicystic, dysplastic kidney, von Hippel-Lindau disease, acquired cystic kidney disease, and tuberous sclerosis.

CT of pancreatic neoplasms. Part II: The unusual tumors

The pancreas gives rise to a remarkable variety of neoplasms other than ductal adenocarcinoma. Although no individual type of tumor in this category is prevalent enough to qualify as common, most types are currently encountered with a frequency far greater than that in decades of the recent past. This change is largely the result of the expanded use of contemporary abdominal imaging. The unusual tumors of the pancreas vary greatly in their biologic behavior and, accordingly, in their clinical consequences and therapeutic requirements. Accurate diagnosis, therefore, can be of considerable clinical relevance. Not only is it worthwhile to distinguish one type of unusual pancreatic tumors from another, it is perhaps of even greater consequence to distinguish the unusual tumors from ordinary pancreatic adenocarcinomas. The goals of this discussion are to expand radiologic awareness of these uncommon but interesting pancreatic neoplasms and to increase familiarity with their diagnostically salient features.

Successful surgical removal of an asymptomatic optic nerve hemangioblastoma in von Hippel-Lindau disease

An asymptomatic patient with a family history of von Hippel-Lindau disease carried the abnormal gene for this disease. An imaging survey that consisted of computed tomography, magnetic resonance imaging, and cerebral angiography revealed an optic nerve hemangioblastoma. The potential for visual loss in the future was the indication for microsurgical intervention. This was the first asymptomatic optic nerve hemangioblastoma to be imaged and the first to be successfully removed without any permanent neurological deficits or vision loss.

Questionability of the benefits of routine laparotomy as the surgical approach for pheochromocytomas and abdominal paragangliomas

BACKGROUND

Improvement of preoperative imaging of pheochromocytomas and abdominal paragangliomas may render routine laparotomy questionable as the surgical approach of choice for these lesions.

METHODS

We studied the records of 100 patients with chromaffin tumors who underwent abdominal exploration. The disease was familial in 28 patients and was malignant in 19. Seventy-five patients had intraadrenal disease (bilateral in 13). Computed tomography (CT), metaiodobenzylguanidine (MIBG) scintigraphy, and magnetic resonance imaging (MRI) were performed since 1979, 1984, and 1987 in 97, 73, and 43 patients, respectively. False-positive and false-negative results were defined as any discrepancy between imaging results and surgical findings.

RESULTS

Overall accuracy of preoperative localization was 85% with CT scan, 77% with MIBG scintigraphy, and 86% with MRI. In unilateral pheochromocytoma, accuracy was 94% with CT scan, 80% with MIBG scintigraphy, and 96% with MRI. When all three studies were performed (n = 38), overall accuracy was 97% and only one extraadrenal tumor in a patient with familial pheochromocytoma was overlooked.

CONCLUSIONS

The outstanding accuracy of available imaging techniques questions the strategy of routine laparotomy for sporadic and seemingly benign pheochromocytomas, favoring more elective approaches such as the posterior approach or laparoscopy.

Detection of a germline mutation and somatic homozygous loss of the von Hippel-Lindau tumor-suppressor gene in a family with a de novo mutation. A combined genetic study, including cytogenetics, PCR/SSCP, FISH, and CGH

von Hippel-Lindau (VHL) disease is a pleiotropic disorder featuring a variety of malignant and benign tumors of the eye, central nervous system, kidney, and adrenal gland. Recently the VHL gene has been identified in the chromosomal region 3p25-26. Prognosis and successful management of VHL patients and their descendants depend on unambiguous diagnosis. Due to recurrent hemangioblastomas, a29-year-old patient without familial history of VHL disease was diagnosed to be at risk for the disease. Histopathological examination of a small renal mass identified a clear cell tumor with a G1 grading. Genetic characterization of the germline and of the renal tumor was performed. Polymerase chain reaction/single strand conformation polymorphism (PCR/SSCP) analysis with primers from the VHL gene identified a deletion of a single nucleotide in exon 2 in the patient's germline and in the tumor, but not in the DNA of his parents. This deletion therefore must be a de novo mutation. Comparative genome hybridization (CGH) and fluorescence in situ hybridization (FISH) analysis of the G1 tumor with differentially labelled yeast artifical chromosome (YAC) clones showed loss of 3p and of the 3p26 signals, respectively. In conclusion, we identified a de novo germline mutation in the VHL gene of a young patient and a somatic chromosome 3p loss at the homologous chromosome 3 in his renal tumor. Our results suggest a recessive mode of inactivation of the VHL gene, providing solid evidence for its tumor-suppressor gene characteristics. Our data show the diagnostic potential of genetic testing, especially in patients without VHL family history. Furthermore, the findings of homozygous inactivation of the VHL gene in a G1 tumor support the notion that the inactivation of the VHL gene is an early event in tumorigenesis of renal cell carcinoma.

Von Hippel-Lindau disease complicated by acute pancreatitis and Evan's syndrome

Von Hippel-Lindau syndrome (VHL) is an autosomal dominant disorder characterized by renal cysts, retinal angiomas, central nervous system hemangioblastomas, and pancreatic cysts. Evan's syndrome is a hematologic disorder characterized by autoimmune thrombocytopenia and autoimmune hemolytic anemia. We present the first case of acute pancreatitis and Evan's syndrome that developed in a patient with von Hippel-Lindau syndrome.