Cystic chondromalacia (endochondral pseudocyst) of the auricle.

We reviewed and studied the histologic features of 23 cases of pseudocysts of auricular cartilage. Our aim was to determine and describe the histologic spectrum of this condition and to delineate the histologic differential diagnostic points. Lesions for which this condition has been mistaken include relapsing polychondritis, chondrodermatitis nodularis helicis, traumatic perichondritis, hemangioma, chondroma, angiosarcoma, and chondrosarcoma. The pathologist who is familiar with the histologic patterns of this condition usually can recognize it readily. When biopsy specimens are small, and the diagnosis is uncertain, clinical features can often suggest the correct diagnosis.