Hereditary Atypical Hyaline Cartilaginous Tumors of the Mastoid

Outcome Objectives: This study aims to describe three unusual cases of atypical hyaline cartilaginous tumors involving the mastoid within a single family and discuss appropriate imaging, work-up, and management of hereditary tumors of the temporal bone.

Methods: A retrospective review was performed in three patients within the same family identified at a tertiary medical center.

Results: Three family members, consisting of a mother and her two biologic children, were identified to have atypical hyaline cartilaginous tumors of the mastoid. All the three family members developed facial nerve dysfunction and conductive hearing loss as part of the presenting symptomatology. The mother presented with a unilateral tumor and had been treated with surgical excision at age of 12 years without recurrence. Her two biologic children, each with different paternity, developed bilateral tumors at younger ages (ages 9 and 11 years). Both children were treated with bilateral tympanomastoidectomy. Pathologic analysis of the tumor revealed a hyaline cartilage neoplasm with mild increased cellularity and myxoid change within the matrix and few areas suggest the possibility of host bone permeation. Although the primary histologic differential diagnosis was grade I chondrosarcoma, based on the clinical presentation, nonaggressive clinical course, and the radiologic location and findings, the decision was made to classify these lesions as atypical hyaline cartilaginous tumors. Frequent MRI monitoring is planned for both the children.

Conclusion: This case series describes the unique presentation of atypical hyaline cartilaginous tumors of the mastoid that appear to be heritable in nature. Further study is required to identify the inciting genetic abnormality.