Endocrine Abstracts

Case history: A 45 year old lady with Von Hippel Lindau syndrome with a complex past medical history presented with symptoms of cauda equina compression. Past medical history includes cerebellar hemangioblastomas, bilateral retinal angiomas, right sided renal cell carcinoma and renal carcinoid tumour treated with partial and then completion nephrectomy, bilateral phaeochromocytoma treated with bilateral adrenalectomy, metastatic neuroendocrine tumour treated with Whipple’s procedure, radiofrequency ablation and embolization of liver metastases and temozolamide, and secondary diabetes mellitus.

Investigations: Whole spine MRI, Octreotide scan, NM bone whole body with SPECT, brain CT, L femur X-ray.

Results and treatment: Octreotide scan was negative for octreotide positive disease. Whole spine MRI revealed a new large expansile and destructive bony vertebral mass in L2 region causing tight cauda equina compression, highly vascularized in keeping with metastatic disease, and a previously noted small non compressive lesion at L5. This L2 lesion was initially thought to be a renal cell carcinoma metastasis. Patient was initially treated with dexamethasone and then neurosurgically for debulking of L2 lesion and L1-3 fixation. Histology revealed metastatic neuroendocrine carcinoma. During the post-operative period while mobilising the patient had a pathological right humeral shaft fracture through lytic lesion treated with right humeral intramedullary nail fixation. NM Bone whole body with SPECT revealed focal areas of increased uptake in anterior skull, posterior skull, midshaft of right humerus, and midshaft of left femur in keeping with bone metastases. Brain CT showed a destructive lesion of left parietal/occipital bones with well-defined surrounding soft tissue compartment measuring 3.7×3.4 cm, confined to extra-axial compartment and causing inward bowing of dura with local mass effect in parietal lobe. Similar 1×1.5 cm destructive lesion in right frontal lobe breaching only inner table of calvarium was also shown. These lesions seem to be new metastatic deposits. Patient has no central nervous system or cerebellar symptoms. In view of asymptomatic skull bone metastases and previous radiotherapy to the posterior fossa decision was made against radiotherapy to the skull/brain. Patient was treated with bisphosphonate infusion and received radiotherapy to L1-3, left femur and right humerus, followed by systemic treatment with Temozolamide.

Conclusions and points for discussion: We describe a complex case of VHL syndrome: back pain leading to diagnosis of L2 lesion initially thought to be a metastasis of RCC that resulted to be a NET metastasis. The post neurosurgical period was complicated by a pathological right humerus fracture, which led to the finding of multiple bone metastases and required nail fixation, bisphosphonate infusion, radiotherapy and systemic treatment with Temozolamide. Ongoing management questions include whether gallium dotate scan might be beneficial for consideration of treatment with lanreotide and whether investigation is necessary to clarify the origin of the bone metastases.