Pseudomyxoma peritonei (PMP) refers to accumulation of mucinous
ascites with or without neoplastic cells in the peritoneal cavity. It most commonly originates from a low or a high grade primary appendiceal
mucinous neoplasm. Though
adenocarcinoma of gall bladder has been reported to give rise to PMP, to the best of our knowledge, this is the first report of a PMP arising from a low grade mucinous tumour of the gall bladder. A 72-year-old patient was diagnosed with PMP 1.5 years after a
cholecystectomy. After initial oral TS1 (combination of
tegafur,
gimeracil and
oteracil) and later intraperitoneal (IP)
chemotherapy with
docetaxel and
cisplatin, the patient was operated with the goal of tumour debulking, including removal of 5.5 L of mucinous
ascites, an
appendectomy, and
ovariectomy. The histopathologic report showed a normal appendix and
metastasis of PMP to the right ovary. After the exclusion of the 2 most common sites of origin (appendix and ovary), the specimen of the
cholecystectomy was reviewed. It showed low grade mucinous tumour in the gall bladder, with immuno-histochemical markers (IHCs) suggestive of CK7, CDX2, MUC 2 positive and CK20, MUC5AC negative. MIB-1 index was 12%. The pathologic report of
cytoreductive surgery performed after 7 cycles of IP
chemotherapy confirmed the diagnosis of PMP originating from low grade mucinous tumour of the gall bladder. Our case report illustrates a
rare disease and highlights that, though peritoneal
metastasis from
gall bladder cancers are known to have a poor prognosis, the peritoneal dissemination from a low grade
mucinous neoplasm of gall bladder (PMP) has a significantly better prognosis due to a better disease biology and improved treatment options currently available for the treatment of PMP.