Key words rectal paraneoplastic syndrome pemphigus
Paraneoplastic pemphigus (paraneoplastic pemphigus, PNP) is a tumor associated with autoimmune syndrome, with characteristic changes in the clinical manifestations, pathology, immunology . PNP common in non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, Castleman disease, thymoma, bronchial squamous cell carcinoma, Hodgkin’s lymphoma and T-cell lymphoma, rectal merge the the PNP very rare , the domestic outside have not been reported in our hospital patients with rectal cancer patients with paraneoplastic pemphigus.
Patients, female, 76 years old, mainly due to “difficult defecation four weeks with bloody mucus two weeks" outpatient “rectal tumor was admitted to hospital on June 22, 2006. Admission examination: body skin visible fusion erythema associated with blisters, erosions, oral and oral mucosa visible erosion, ulcers, bleeding, abdominal shaped flat no gastrointestinal shaped and peristaltic waves. Abdomen soft, no tenderness and less clear tumor, active bowel sounds 4 times / min, DRE and hard mass, finger blood-stained. Laboratory tests: WBC 6.8 × 109 / L, 68.9% neutrophils, hemoglobin 113g / L, total protein 64.6 g of / L, and albumin 36 g / L, and the CEA 14.26μg / L CA19-9 124KU / L, and chest piece: no abnormal lungs. Abdominal B ultrasound: liver, gallbladder, pancreas, spleen, and kidneys were normal. Skin biopsy: direct immunofluorescence with IgG and C3 deposition prickle cells and the basement membrane. Colonoscopy: rectal intestine visible around 1/2 intestine irregular tumor, mucosal ulceration, biopsy report: well-differentiated adenocarcinoma. At this point, the patients diagnosed with rectal cancer merger paraneoplastic pemphigus give skin lesions eased hormone immunosuppressive therapy, improve mucosal damage, did not undergo surgery, died eight months after the extensive transfer of tumor.
The paraneoplastic pemphigus performance : mucosal erosion and pleomorphic lesions; Histopathology showed acantholytic keratinocytes cell necrosis and dermal-epidermal junction dense mononuclear cell infiltration; direct immunofluorescence shows IgG and (or) C3 in the epidermis and (or) basement membrane zone the deposition; Serum memory for a variety of epithelial autoantibodies; immunoprecipitation measured with a variety of the epithelial protein antigen reaction autoantibodies.
PNP pathogenesis may humoral immune response related : tumor antigen with epidermal protein has a molecular similarity, the immune response of the body’s anti-tumor antigen cross-react with normal epidermis. Other possible mechanisms include the primary immune response or inflammatory processes leading to tissue damage, so that no tissue component as T or B-cell recognition of proteins “exposed" to the immune system, resulting in a secondary immune response.
PNP clinical manifestations of multiple organ common symptoms are refractory stomatitis, mouth and oral mucosa erosions, ulcers, bleeding. Patients may have multiple heavier mucosal damage involving the bronchus, esophagus, intestinal and genital mucosa. Another outstanding performance as a painful erosive conjunctivitis. The lesions, pleomor, the common fusion erythema associated with blisters, erosions, and crusting, may also have the papulosquamous damage and erythema multiforme, target-shaped damage.
Lesions Histopathology showed acantholytic lysis can occur in the basal cell layer or the upper spinous cells, the formation of blisters within the epidermis. Liquefaction degeneration of the basal cells, superficial dermal dense infiltration of inflammatory cells, mainly lymphocytes forming cells  scattered necrotic keratinocytes in the epidermis. The direct immunofluorescence display prickle cells and the basement membrane with IgG and C3 deposition. Indirect immunofluorescence can be detected in the serum IgG antibody capable of binding to the ratchet between cells and the basement membrane zone. Western blot or immunoprecipitation method detection PNP serum the autoantibody can help diagnosis. About 2/3PNP cases lesions occurred in patients with existing tumors, 1/3 of the cases the tumor was detected only after the emergence of the skin and mucous membrane disease. Patients suspected PNP should be the chest, abdomen and pelvic CT scans combined with enhanced scan to detect potential tumors.
The PNP’s treatment includes two aspects : the treatment of tumors and the treatment of autoimmune reactions. If able to remove the tumor, Castleman’s disease and thymoma benign skin lesions after 6 to 18 months significantly improved or completely eliminated, 90% of the patients circulating antibody titers decreased. For cases of malignant tumors, for the treatment of tumors are usually not affect the activity of the disease, and still does not have an exact and effective treatment. Skin lesions usually the response to treatment is better than the mucosal damage. Most of the drug treatment of autoimmune bullous diseases also treatment of PNP. However, the majority of patients with malignant tumors showed progressive development, the diagnosis of 1 month to 2 years died of complications of the patients were treated with dexamethasone and cyclophosphamide pulse therapy and then oral treatment with low-dose cyclophosphamide, skin lesions partial remission, mucosal damage improved, but not treated surgically, survival of 8 months.