Adenocarcinoma of the ethmoid following radiotherapy for bilateral retinoblastoma.

Adenocarcinoma of the ethmoid sinus is rare, representing only 4-8% of malignancies of the paranasal sinuses. An extraordinary case of papillary adenocarcinoma of the ethmoid sinus arising 30 years following high-dose radiotherapy for bilateral retinoblastoma is presented. Retinoblastoma, though occurring only once in every 23,000 to 34,000 births, is the most common malignant intraocular tumor of childhood. Second fatal mesenchymal and epithelial primaries have been described in 8.5% of patients with bilateral retinoblastomas previously treated with radiotherapy; however, papillary adenocarcinoma arising within the paranasal sinuses has not been reported. Histologically, the findings of a papillary pattern of poorly differentiated, mucicarmine-staining cells enclosing gland-like spaces, and the absence of pseudorosettes, melanin, mesenchymal and peripheral neural elements supports an epithelial origin of this tumor. Agressive treatment including partial maxillectomy, radical pansinusectomy, radical neck dissection followed by regional radiotherapy and systemic chemotherapy failed to prevent the development of fatal hepatic metastases. The high incidence of second fatal primary neoplasms in patients with bilateral retinoblastomas receiving radiation suggests an innate susceptibility that may add to the risk of radiotherapy. Careful long-term head and neck surveillance is mandatory if early aggressive management of these extremely lethal tumors is to be successful.