A new aspect of metastasis in cutaneous cancer: two cases of presacral squamous cell carcinoma with metastases to internal iliac nodes.

We report 2 cases of presacral squamous cell carcinoma. In these cases, it was suspicious that the tumor disseminated to the internal iliac nodes through the direct pathway called the neurovascular lymphatic space (NVLS) around the superior/inferior gluteal vessels or sciatic nerve bypassing external iliac nodes. NVLS was initially reported as accessory pathway which follows the major vessels forming a sheath like structure with an actual or potential space between the vessel wall and the enveloping membrane. NVLS has been reported to be observed as a tubular shadow within the neurovascular sheath by lymphangiographies of lymphedema patients using oil-based contrast material. These cases provide insights into the potential pathway through which a cutaneous tumor disseminates.

Morphological assessment of early axonal regeneration in end-to-side nerve coaptation models.

Histological changes were observed in peripheral nerves following end-to-side nerve coaptation to determine the effects of perineurial opening and deliberate donor nerve injury during surgery. Twenty rats were randomised into four groups as follows: group 1, end-to-side nerve coaptation without perineurial opening; group 2, end-to-side nerve coaptation with simple perineurial opening; group 3, end-to-side nerve coaptation with partial crush injury after perineurial opening; group 4, end-to-side nerve coaptation with partial neurotomy after perineurial opening. Seven days after coaptation of the musculocutaneous (recipient) nerve to the ulnar (donor) nerve, the nerves were immunohistochemically analysed using antibodies against neurofilament-H (RT97) and phosphorylated GAP-43 (p-GAP-43). The former labels all axons, including regenerating axons and degenerated axonal debris, while the latter only labels regenerating axons. Results demonstrated no regenerating nerves in the recipient nerve of group 1. In group 2, because nerve herniation from the perineurial opening partially injured donor nerve fibres, some regenerating axons extended proximally and distally along the partially injured fibres in the donor nerve; some of these regenerating axons also extended into the recipient nerve via the perineurial opening. In groups 3 and 4, thin regenerating axons were more prominent in recipient and donor nerves compared with group 2. Statistical evaluation revealed increased efficacy of perineurial opening and deliberate donor nerve injury in end-to-side nerve coaptation, suggesting that partial nerve fibre herniation with partial axonotmesis or neurotomesis was important for effective axonal regeneration in end-to-side nerve coaptation.