Generalized Trichoepitheliomas With Alopecia and Myasthenia Gravis: Clinicopathologic and Immunohistochemical Study and Comparison With Classic and Desmoplastic Trichoepithelioma

The study reported on a patient with a syndrome characterized by smooth facial papules and nodules, alopecia affecting eyebrows, eyelashes, and most body hair, mild scalp hair alopecia, possible hypohidrosis, and myasthenia gravis. The clinical, histologic, and immunohistochemical findings were compared with classic and desmoplastic trichoepitheliomas. All 14 biopsy specimens from the patient showed a network of basaloid cells with follicular differentiation, similar to classic trichoepithelioma. The tumor cells exhibited a keratin phenotype typical of infrainfundibular outer root sheath cells. The study concluded that the lesions were trichoepitheliomas and suggested the condition might represent a new syndrome related to generalized hair follicle hamartoma or a variant. The presence of generalized trichoepitheliomas with alopecia should raise the possibility of myasthenia gravis.