Adenocarcinoma of the cervix is less common than squamous cell carcinoma. Gastric-type mucinous adenocarcinoma(GAS) is approximately 10-25% of cervical cancers. Minimal deviation adenocarcinoma of mucinous type (adenoma malignum) is considered an extremely well differentiated variant of GAS. There is an association between gastric-type cervical lesions and Peutz-Jeghers syndrome. Among GAS, approximately 10% are associated with Peutz-Jeghers syndrome, an autosomal dominant disorder. The incidence of GAS in Peutz-Jeghers patients is estimated to be 15-30%. We present a rare case that of adenoma malignum was diagnosed by colposcopic biopsy in woman with Peutz-Jeghers syndrome. This case was pathologically confirmed to GAS after surgery.