[Laparoscopic Abdominoperineal Resection of the Rectum in a Case with Pagetoid Spread of Anal Canal Carcinoma].

The patient, a man in his 60s, first noticed an elevated lesion around the anus 3 years ago. The lesion failed to subside with the topical drug preparations prescribed at a local clinic, and the patient was referred to the Department of Dermatology of our hospital for further workup and treatment. The findings of biopsy from the lesion suggested skin infiltration of anal canal carcinoma, and the patient was referred to the Department of Surgery. Examination here revealed only induration of the anal canal, with no abnormality of the rectal mucosa even when the endoscope was reversed to visualize the rectum. Examination by various imaging modalities failed to reveal any metastases to the lymph nodes or distant organs, and the primary lesion remained unidentified. Laparoscopic abdominoperineal excision of the rectum was performed, beginning with anal manipulation. First, a 15-mm margin was set on the skin from the tumor edge, and the skin stump was divided into 4 equal portions. After confirming by rapid intraoperative frozen-section examination that the margin was negative along the full circumference, anal manipulation was performed, leaving a distance in the vertical direction immediately below the tumor. Upon completion of the anal manipulation, intraperitoneal manipulation was performed in a routine manner. The anal skin was relaxed subcutaneously, as done during mastectomy, and the subsequent suture closure could be done smoothly. The tumor was classified as pT1bN0M0, pStage Ⅰ. The experience with this case indicates that biopsy should be proactively employed for the diagnosis in such cases, and that proactive skin biopsy is useful when dealing with intractable anal skin lesions.

Conformational epitope mapping and IgG subclass distribution of desmoglein 3 in paraneoplastic pemphigus.

BACKGROUND: Pemphigus vulgaris (PV) shows autoimmune reaction against desmoglein 3 (Dsg3), whereas paraneoplastic pemphigus (PNP) shows autoimmune reaction against Dsg3 as well as numerous members of the plakin family. It has been demonstrated that in PV, dominant epitopes reside in N-terminal adhesive regions of Dsg3 and that the dominant IgG subclass against Dsg3 is IgG4. OBJECTIVE: We attempted to map conformational epitopes and analyze IgG subclass distribution against Dsg3 in PNP. METHOD: Epitopes on Dsg3 for circulating IgG autoantibodies from PNP (n = 22) were studied with competition enzyme-linked immunosorbent assay (ELISA) using domain-swapped molecules between Dsg3 and Dsg1 and were compared with those for IgG autoantibodies from PV (n = 22). IgG subclass distribution was analyzed with PNP serum by Dsg3 ELISA (n = 17). RESULTS: Epitopes on Dsg3 in PNP were distributed more broadly through the extracellular domain of Dsg3 than were those in PV, although the N-terminal extracellular domains of Dsg3 were more frequently recognized than the C-terminal extracellular domains. IgG subclass in PNP was IgG1 and IgG2 dominant. CONCLUSION: Autoimmune response against Dsg3 in PNP is more diversified than that in PV, a finding that suggests PNP and PV have different pathophysiologic mechanisms for triggering production of anti-Dsg3 IgG.