An Unusual Lesion of the Clivus

Introduction: A patient presented with a 2-year history of memory disturbance and headaches. Imaging revealed a clivus mass, which was subsequently shown to be a large focus of extramedullary hematopoiesis (EMH) on biopsy.

Case Report: A 32-year-old Indian woman with beta-thalassaemia and sickle cell disease was referred to the ENT clinic from Neurosurgery following identification of a clival abnormality on imaging. Examination revealed a nasal septal deviation to the right with satisfactory access to the sphenoid sinus from the left. Neurological examination was normal. An endoscopic image-guided transsphenoidal biopsy of the clival lesion was performed and found to bleed significantly. Histology demonstrated EMH. The radiological findings were: CT demonstrated a 2-cm mass lesion affecting the base of the sphenoid and extending up to the posterior clinoids, reaching the base of the pterygoid plates on the left side. Hemangioma was considered in the differential diagnosis. However, MRI showed little bony expansion and a differential diagnosis of chordoma, dermoid cyst, and fibrodysplasia was included. Histological findings were: The biopsy showed the presence of bone marrow demonstrating erythroid hyperplasia and small aggregates of B-cell lymphocytes. The features were considered compatible with erythroid hyperplasia associated with hemolytic anemia. Management was: The patient was reassured that she did not have a neoplastic lesion and was referred back to the hematologists for further management of her sickling beta-thalassaemia.

Conclusions: EMH occurs in response to hemolytic anemia outside the reticuloendothelial system, and this is an unusual presentation to ENT as a clivus mass. It is occasionally seen in the calvarial skull, but this is the first report occurring in the anterior skull base.