Rare orbitocranial tumour in an adult

A 35-year-old lady presented with recurrent episodes of painful right upper lid swelling and ptosis of 6 months' duration. The symptoms would subside with oral antibiotics and painkillers. She had also been undergoing treatment for 1 year for multiple painful osteolytic lesions in the long bones and axial skeleton for which no definite diagnosis had been made, despite several radiological and serological investigations having been performed. Computed tomographic scan showed a soft tissue lesion in the superolateral part of the right orbit with erosion of the adjacent bone. Lacrimal gland biopsy showed non-specific inflammatory changes. She was referred for full work-up to exclude lymphoma and metastasis. Magnetic resonance imaging revealed an enhancing soft tissue mass in the right anterior cranial fossa eroding the lateral orbital wall and extending into the orbit. Another mass encased the superior sagittal sinus. Bone marrow biopsy showed near total replacement of marrow cells by a round cell tumour. Immunohistochemical studies revealed that the tumour cells expressed neuron specific enolase and chromogranin. The pathological findings suggested a diagnosis of neuroendocrine tumour though neuroblastoma could not be unequivocally ruled out. A(131) I-metaiodobenzylguanidine scan showed no uptake. Radiologic studies suggested multiple bony metastases. No other site of primary tumour was found so there was a strong possibility of it being a primary orbito-cranial neurogenic tumour. Neuroblastomas and neuroendocrine tumours are very rare in adults. The orbit is an unusual site for a primary of this nature. In addition, it is quite difficult to make a specific diagnosis in a less differentiated tumour.