Synovial sarcoma involving the median nerve: a case report.

Synovial sarcoma may arise from different and unusual sites. Here a case of biphasic synovial sarcoma arising or invading the radial nerve in a 59-year-old female classically showing chromosomal reciprocal translocation (X; 18) is reported. The differential diagnosis from similar tumors is discussed.

δ-Aminolevulinic acid dehydratase genotype predicts toxic effects of lead on workers' peripheral nervous system.

There is a wide variation in sensitivity to lead (Pb) exposure, which may be due to genetic susceptibility towards Pb. We investigated whether a polymorphism (rs1800435) in the δ-aminolevulinic acid dehydratase (ALAD) gene affected the toxicokinetics and toxicodynamics of Pb. Among 461 Chinese Pb-exposed storage battery and 175 unexposed workers, allele frequencies for the ALAD1 and ALAD2 alleles were 0.968 and 0.032, respectively. The Pb-exposed workers had a higher fraction of the ALAD1-2/2-2 genotype than unexposed workers (7.8% vs. 2.3%, p=0.01). The Pb levels in blood (B-Pb) and urine (U-Pb) were higher in Pb-exposed workers carrying the ALAD2 allele compared to homozygotes for ALAD1 (median B-Pb: 606 vs. 499 µg/L; U-Pb: 233 vs. 164 µg/g creatinine), while there was no statistically significant difference in the unexposed controls (median: 24 vs. 37 µg/L, and 3.9 vs. 6.4µg/g creatinine, respectively). High B-Pb and U-Pb were associated with statistically significantly lower sensory and motor conduction velocities in the median, ulnar and peroneal nerves. At the same B-Pb and U-Pb, ALAD1 homozygotes had lower conduction velocities than the ALAD2 carriers. There were similar trends for toxic effects on haem synthesis (zinc protoporphyrin and haemoglobin in blood) and renal function (albumin and N-acetyl-d-ß-acetylglucosaminidase in urine), but without statistical significance. There was no difference in Pb toxicokinetics and toxicodynamics associated with VDR BsmI polymorphism. Our results show that the ALAD genotype modifies the relationship between Pb and its toxic effects on the peripheral nervous system. This must be considered in the assessment of risks at Pb exposure.

Charcot-Marie-Tooth 1A concurrent with schwannomas of the spinal cord and median nerve.

We identified Charcot-Marie-Tooth disease type 1A (CMT1A) in a family with schwannomas in the spinal cord and median nerve. The CMT1A in this family showed an autosomal dominant pattern, like other CMT patients with PMP22 duplication, and the family also indicated a possible genetic predisposition to schwannomas by 'mother-to-son' transmission. CMT1A is mainly caused by duplication of chromosome 17p11.2-p12 (PMP22 gene duplication). A schwannoma is a benign encapsulated tumor originating from a Schwann cell. A case of hereditary neuropathy with liability to pressure palsies (HNPP) concurrent with schwannoma has been previously reported. Although it seems that the co-occurrence of CMT1A and schwannomas in a family would be the result of independent events, we could not completely ignore the possibility that the coincidence of two diseases might be due to a shared genetic background.

Ossifying neuropathy of the median nerve at level of the distal forearm and carpal tunnel in a patient with familial history of heterotopic calcification.

We report an uncommon case of heterotopic ossification affecting the median nerve at the level of the distal forearm and carpal tunnel with some unusual features: its length, the concomitant involvement of the ulnar nerve at Guyon's canal and a positive family history of heterotopic ossification.

ErbB receptors modulation in different types of peripheral nerve regeneration.

ErbBs are a family of receptors involved in the trophic maintenance of Schwann cells. Little is known about their expression changes during peripheral nerve regeneration. The aim of this study was thus to investigate variations in ErbBs after end-to-end and end-to-side nerve regeneration in the rat median nerve model. Expression of ErbBs was assessed at 7, 14, and 28 days postoperatively by real-time PCR. Results showed that expression of ErbB1 and ErbB4 mRNAs was downregulated, whereas ErbB3 mRNA was upregulated. No significant changes in ErbB2 mRNA were detected. Our results suggest that ErbBs changes are involved in the molecular response to peripheral nerve injuries.

Hereditary neuropathy with liability to pressure palsies in a Turkish patient (HNPP): a rare cause of entrapment neuropathies in young adults.

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant nerve disease usually caused by 1,5 Mb deletion on chromosome 17p11.2.2-p12, the region where the PMP-22 gene is located. The patients with HNPP usually have relapsing and remitting entrapment neuropathies due to compression. We present a 14-year-old male who had acute onset, right-sided ulnar nerve entrapment at the elbow. He had electrophysiological findings of bilateral ulnar nerve entrapments (more severe at the right side) at the elbow and bilateral median nerve entrapment at the wrist. Genetic tests of the patient demonstrated deletions in the 17p11.2 region. The patient underwent decompressive surgery for ulnar nerve entrapment at the elbow and completely recovered two months after the event. Although HNPP is extremely rare, it should be taken into consideration in young adults with entrapment neuropathies.

Hereditary neuropathy with liability to pressure palsy combined with schwannomas of the median and medial plantar nerves.

A 42-year-old woman was surgically treated for carpal tunnel syndrome, revealing schwannoma of the median nerve. A year later, she developed a tarsal tunnel syndrome. At time of this diagnosis, hereditary neuropathy with liability to pressure palsies (HNPP) was diagnosed genetically and a schwannoma of the medial plantar nerve was treated surgically. The occurrence of HNPP and schwannomas in the same patient might be purely coincidental, but it is tempting to speculate that they share a common genetic basis.