Paraneoplastic gastrointestinal motor dysfunction: Clinical and laboratorycharacteristics

OBJECTIVES: The aim of this study was to describe the clinical, manometric, and serological characteristics of 12 patients with paraneoplastic GI moto r dysfunction and to assess the contributory role of diagnostic tests. METHODS: Twelve patients diagnosed with malignant tumors and GI motor dysfu nction were identified at the Mayo Clinic from 1985 to 1996. RESULTS: Cancers identified were: nine small cell lung carcinoma (SCLC), on e anaplastic lung adenocarcinoma, one retroperitoneal lymphoma, and one ova rian papillary serous adenocarcinoma. GI symptoms preceded the tumor diagno sis in all cases of SCLC (mean, -8.7 months, range, -1 to -24 months, n = 9 ). The diagnosis of a malignant tumor preceded the onset of GI symptoms in the three patients with other neoplasms (6, 12, and 24 months). Five of the nine patients found to have SCLC had no evidence of tumor on initial chest x-ray. One or more paraneoplastic autoantibodies were found in 10 of the 1 1 patients tested by autoimmune serology. Type 1 antineuronal nuclear antib ody (ANNA-1 or anti-Hu) was detected in eight of the nine patients with SCL C (one patient was not tested). The patient with ovarian carcinoma had type 1 Purkinje cell cytoplasmic antibody (PCA-1 or anti-Yo). N-type calcium ch annel antibodies were found in one patient with SCLC, one with a retroperit oneal B cell lymphoma, and one with ovarian carcinoma. Gastric emptying was delayed in 89% (eight of nine tested) and 80% (four of five tested) had es ophageal dysmotility. Autonomic reflex tests were abnormal in the seven pat ients tested. CONCLUSIONS: The diagnosis of paraneoplastic GI motor dysfunction requires a high index of clinical suspicion. A panel of serological tests for parane oplastic autoantibodies, scintigraphic gastric emptying, and esophageal man ometry are useful as first-line screening tests. Seropositivity for ANNA-1, PCA-1, or N-type calcium channel-binding antibodies should prompt further evaluation for an underlying malignancy even when routine imaging studies a re negative.