Autopsy Report of a 7Year Old Patient with the Mo

Authors: George Imataka Hideo Yamanouchi Junko Hirato Mitsuoki Eguchi Masaru Kojima Koichi Honma Osamu Arisaka

Publish Date: 2013/03/24

Volume: 67, Issue: 2, Pages: 813-817

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Abstract

We present here a long survival case of a patient with the mosaic form of trisomy 13 who died of aspiration pneumonia at the age of 7 years and 4 months The autopsy revealed olfactory aplasia and fenestration of the septum pellucidum and dilated lateral ventricles and atrophic hippocampus Furthermore there were numerous “torpedos” ie swollen fusiform Purkinje cell axons mostly in the granular layer underneath the Purkinje cell layer and occasionally in the granular layer Similar neuropathological findings have been reported in elderly cases of essential tremor Parkinson’s disease or Alzheimer’s disease Precise mechanism for this axonal change is still unclear These pathological changes have never previously been reported in the literature on trisomy 13 and the present patient is one of the oldest autopsied individuals with the mosaic trisomy 13The trisomy 13 syndrome also called Patau syndrome was first reported in 1960 1 It is a congenital anomaly syndrome caused by accessory chromosome 13 of the D1 group Clinically this syndrome is manifested by variable deformities and their complications Most patients with this syndrome die soon after birth because of the severe congenital heart disease and brain deformity The mortality rate is approx 50  in the first month of life and 90  during the first year of life 2 Although a few cases of longer survival have been reported 3 4 there have been no published reports to date on neuropathological findings in long survival cases with trisomy 13 Here we report an autopsy case of a 7yearold boy with mosaic type of the trisomy 13 syndrome This autopsy in one of the longest survival cases in the literaturea The auditory brainstem response to 100 dB reveals prolonged wave I latency 29 and 30 ms in the left and right sides respectively b The visualevoked potential shows intact wave components with delayed latency c The shortlatency somatosensory evoked potential demonstrates prolonged central conduction time 704 msa Hematoxylin–eosin staining of peripheral blood neutrophils reveals hypersegmentation and drumsticks of neutrophil nuclei magnification ×100 b Electron microscopy JOEL Tokyo Japan magnification ×100 reveals nuclear pockets and dendritic deformation of mitochondriaa Decreased melanin granule is observed in pars compacta of the substantia nigra hematoxylin–eosin staining ×100 b The presence of characteristic axonal swelling of Purkinje cells torpedoes neurofilament ×100 c Similar axonal swelling of Purkinje cells is seen in the molecular layer Bodian ×200A commonly encountered brain anomaly in trisomy 13 is holoprosencephaly which is a brain disorder characterized by a failure of differentiation and a various degree of cleavage of the prosencephalon 5 This patient exhibited olfactory aplasia and partial dysgenesis of the septum pellucidum However there was no fusion of cerebral hemispheres nor a partial or complete absence of the corpus callosum Olfactory aplasia is sometimes associated with septooptic dysplasia 6 However this diagnosis was not applicable to our patient because of incomplete absence of septum pellucidum Furthermore the autopsy revealed a relatively wellpreserved optic tract Isolated olfactory aplasia has never previously been reported in trisomy 13The mortality is generally associated with the severity of deformities in the central nervous system heart and respiratory system To the best of our knowledge our patient is one of the longest survivors with trisomy 13 subjected to autopsy The patient’s long survival was due to the absence of complications associated with deformities of major organs such as the brain the heart or the lungs Another unique feature in our case was the presence of numerous torpedoes ie swollen axons of Purkinje cells within the granular layer The precise mechanism for this axonal change remains unknown It has been reported in several neuropathologic conditions with diffuse or focal cerebellar changes such as necrotic lesions degenerative disease involving the cerebellum elderly cases of essential tremor Parkinson’s disease Alzheimer’s disease cerebellar injury and aging 7 8 9 However this characteristic change in the cerebellum has never previously been reported in autopsy reports on trisomy 13

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