Temporal bone histopathology in trisomy 18 syndrome: a report of two cases.

Temporal bone histopathological findings of two patients with trisomy 18 syndrome are described. Many of the abnormalities previously described were seen in the present cases; namely, atresia of the external auditory canal, aberrant course of the tensor tympani muscle, malformed stapes, aberrant course of the facial nerve with an obtuse angulation at the first genu and displacement of geniculate ganglion cells into the internal auditory canal, shortened cochlea with decreased spiral ganglion cell population, and vestibular anomalies, such as bony and membranous blockage of the superior semicircular canal. Moreover, an extremely underdeveloped malleus and incus continuous with a persistent Meckel's cartilage were observed.

Tumor-forming acute myeloid leukemia with facial paralysis.

A 55-year-old male with acute myeloid leukemia, which had been well controlled for 2 years, developed a sudden onset of facial palsy. Otologic examinations proved the right mastoid bone to be infiltrated by leukemic cells, which formed a nonchloroma to occlude the right external auditory canal. The precise site for the right facial paralysis by tumor formation was found in the intrastapedial region of peripheral portion of the right facial nerve.

Temporal bone histopathology of atresia auris congenita with chromosome aberration.

Temporal bone findings in two infants demonstrating congenital aural atresia with microtia were presented focusing mainly on the external and middle ears. These two cases were proved to have chromosome aberration that is, 13-15 trisomy and extra chromosome in group G individually. Temporal bones showed the multiple anomalies through the external, middle and internal ears.