title: Primary Clear Cell Microcystic Adenoma of the Sinonasal Cavity: Pathological or Fortuitous Association?
abstract: Primary clear cell microcystic adenoma of the sinonasal cavity is rare. It has previously been described only as a VHL-associated tumour. Von Hippel-Lindau (VHL) syndrome is an inherited cancer syndrome characterised by an elevated risk of neoplasia including clear cell renal cell carcinoma (ccRCC), haemangioblastoma, and phaeochromocytoma. We describe the second reported case of a primary clear cell microcystic adenoma of the sinonasal cavity. The 39-year-old patient with VHL syndrome had previously undergone resection and ablation of ccRCC. He presented with epistaxis. Imaging demonstrated a mass in the ethmoid sinus. Initial clinical suspicion was of metastatic ccRCC. However, tumour morphology and immunoprofile were distinct from the previous ccRCC and supported a diagnosis of primary microcystic adenoma. Analysis of DNA extracted from sinonasal tumour tissue did not show loss of the wild-type allele at theVHLlocus. Although this did not support tumour association with VHL disease, it was not possible to look for a loss-of-function mutation. The association of primary microcystic adenoma of the sinonasal cavity with VHL disease remains speculative. These lesions are benign but are likely to require regular surveillance. Such tumours may require repeated surgical excision.
authors.affiliation: Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Rosalin
authors.identifier: 0000-0002-8548-1178
authors.initials: R
authors.lastname: Cooper
authors.affiliation: Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Hannah
authors.initials: H
authors.lastname: Markham
authors.affiliation: Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Jeffery
authors.initials: J
authors.lastname: Theaker
authors.affiliation: Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Adrian
authors.initials: A
authors.lastname: Bateman
authors.affiliation: Wessex Regional Genetics Laboratory, Salisbury NHS Foundation Trust, Salisbury, UK.
authors.forename: David
authors.identifier: 0000-0001-8686-558X
authors.initials: D
authors.lastname: Bunyan
authors.affiliation: Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Sommerlad
authors.affiliation: University of Southampton, Southampton, UK; Wessex Clinical Genetics Service, University Hospitals Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Gillian
authors.initials: G
authors.lastname: Crawford
authors.affiliation: University of Southampton, Southampton, UK; Wessex Clinical Genetics Service, University Hospitals Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Diana
authors.initials: D
authors.lastname: Eccles