Sukov and coworkers (11) failed to detect ALK-1 immunostaining in various spindle cell lesions of the bladder, including 16 leiomyosarcomas, 8 sarcomatoid carcinomas, 3 embryonal rhabdomyosarcomas, 3 reactive myofibroblastic proliferations, 1 malignant solitary fibrous tumor, and 1 schwannoma.
Sukov and coworkers (11) found ALK gene rearrangements in 67% of tumors in a series that included 21 cases of IMTs of the urinary bladder, but found no such ALK gene rearrangement in the other tumors among 32 non-IMTs tested, including 16 leiomyosarcomas and 3 embryonal rhabdomyosarcomas.
14) Skeletal muscle markers, myoD1, and myogenin can be of value if embryonal rhabdomyosarcoma is a diagnostic consideration.
Microscopically, embryonal rhabdomyosarcomas are pleomorphic.
The author reports a case of embryonal rhabdomyosarcoma of the temporal bone with cranial nerve palsies and extension into the parapharyngeal space in a 4-year-old boy.
In this article, the author reports a case of embryonal rhabdomyosarcoma of the temporal bone with cranial nerve palsies and extension into the parapharyngeal space.
Histopathologic examination of the excised mass revealed that it was an embryonal rhabdomyosarcoma (figure 2).