[Anal gland carcinoma with osteoblastic metastases]

A 52-year-old woman was admitted because of anal pain of 6 weeks duration. Physical examination was unremarkable except for a cherry-sized swelling, painful to pressure, on rectal examination. As the erythrocyte sedimentation rate and C-reactive protein were increased (69/115 and 12.1 mg/dl, respectively) and abscess was diagnosed. Carcinoembryonic antigen was within normal limits.

At rectoscopy a fluctuating abscess-linked swelling was found at 3 cm and a submucous tumour at 5 cm from the anus.

The abscess was cut open and at the level of the dentate line a submucous adenocarcinoma about 3 cm in diameter was resected. A small residual tumour was removed by abdomino-perineal rectal extirpation. As histologically it was an adenocarcinoma not of colorectal type, without relationship to rectal mucosa but in close contact to the anal glands, and the further course did not indicate a metastasis from another primary tumour, the diagnosis of anal gland adenocarcinoma was established. A local recurrency was resected 6 months later, followed by combined radio- and chemotherapy. A diffuse osteoblastic metastasis was discovered later and the patient died 21 months after diagnosis.

An osteoblastic metastasis from an anal gland carcinoma, as occurred in this case, has not been previously reported.