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Washington University Experience | NEOPLASMS - CRANIAL AND PARASPINAL NERVEs | Malignant Peripheral Nerve Sheath Tumor (MPNST) | 6A0 Case 6 History
Case 6 History (USC Case, thanks Drs. Kyle Hurth and Linda Szymanski) ---- The patient is a 70 year old man with a past medical history of a malignant peripheral nerve sheath tumor status post partial sacretectomy, followed by a ~6 week long course of adjuvant radiation therapy, and decline in mental status. Past medical history included: low back surgery ~20 years ago, anterior cervical discectomy with fusion, multiple joint surgeries (left knee x3, right knee x4, left shoulder x1, right shoulder x2), partial colectomy, appendectomy, osteoarthritis, diabetes mellitus, hypertension, hyperlipidemia, and hypothyroidism. Per clinical records, the patient initially presented in early 2014 with perineal pain and prostate issues. MRI showed a 3.8 x 2.9 x 3.9 cm lucent/lytic mass within the sacrum along with cortical destruction of portions of the sacrum. The patient underwent S2-S4 laminectomy and S2-S3 partial sacretectomy in February 2015 with a final diagnosis of malignant nerve sheath tumor arising in a background of neurofibroma. Postoperatively, he required intermittent catheterization for urinary retention. Radiation therapy was begun in March 2015 and during the course of his radiation therapy, he developed worsening pain in his buttocks and legs bilaterally and was unable to tolerate further radiation treatment. The patient’s back and leg pain left him unable to ambulate. He underwent placement of a lumbar tunneled epidural catheter for pain control. He developed confusion with waxing/waning consciousness and hallucinations. and was alert and oriented to self only. Hallucinations included seeing people and animals in the room. Secondary to the complex treatment of his pain with multiple medications (including: duloxetine, Lyrica, and opiates) the possibility of neuroleptic malignant syndrome (NMS), and/or serotonin syndrome were considered. The patient had tonic jerk-like movements of his extremities and tremors. The possibility of the development of extrapyramidal symptoms (EPS) was considered. Urine culture returned positive for Enterococcus faecalis which was treated with antibiotics. ---- Secondary to anesthesia requirements for pain and worsening altered mental status, his radiation therapy was terminated in May 2015 with 68 Gy (of 70 Gy planned) administered. Multiple repeat CT scans of the head showed dilated ventricles concerning for normal pressure hydrocephalus and/or hydrocephalus ex vacuo (age related change) and the possibility of a small old left cerebellar infarct. The patient underwent lumbar puncture which showed: numerous neutrophils, WBC 702 cells/mcL, Glucose 59 mg/dL, and Protein > 600 mg/dL. He was started on vancomycin, ceftriaxone, and ampicillin. MRI of the lumbar spine (June 2015) reported interval development of marked indistinctness of the cauda equina nerve roots with diffuse leptomeningeal enhancement along the entire length of the cauda equina nerve roots. Combined with lumbar puncture findings an infectious leptomeningitis was suspected. MRI of the head in early June 2015 was relatively unremarkable; however, 8 days later there was extensive diffuse leptomeningeal FLAIR signal thought to be most consistent with leptomeningitis. However, blood and CSF cultures were negative for an exhaustive panel of organisms. The patient was transferred to the ICU and intubated due to acute respiratory failure and distress. Laminectomy with intradural exploration of the thecal sac with a diagnosis of nerve with superimposed treatment effect and atypical necrotic cells consistent with involvement by malignant peripheral nerve sheath tumor with extensive necrosis. There were no bacterial, fungal organisms, or AFB detected in the surgical specimen. He had also developed ventilator associated pneumonia, which resolved with antibiotic treatment. The patient continued to show no neurologic improvement and he passed away. ---- At autopsy the weight of the unfixed brain was 1490g. The leptomeninges were variably opaque with ill-defined white gelatinous discoloration. Nerves and vertebrobasilar vessels were adherent to the undersurface of the brain. The gyral and sulcal pattern was relatively normal with no evidence of atrophy or cerebral edema. Transverse sections of the brain stem reveal friable tissue and features suggestive of mild anterior-posterior (AP) elongation of the midbrain. Leptomeningeal surfaces appear thickened and portions of cranial nerves exiting the brainstem appear matted to its surface. Sections of cerebellum show white discoloration of the superficial surface of folia. The spinal cord shows multifocal areas of adhesion to the dura. The spinal nerves of the cauda equina are matted together and adherent to the dura.
