Women with peritoneal carcinomatosis of unknown origin: efficacy of image‐guided biopsy to determine site‐specific diagnosis

Objectives  To evaluate the use of image‐guided biopsy (IGB) in routine clinical practice to obtain site‐specific diagnoses in women presenting with peritoneal carcinomatosis (PC). Study design  Retrospective case study. Setting  Tertiary referral centre. Population  A total of 149 consecutive women with PC who underwent IGB. Methods  Biopsy was performed in women considered unsuitable for primary surgery because of poor performance status or disease unlikely to be optimally debulked, with a prior history of malignancy or where there was clinicoradiological uncertainty about primary tumour site. Standard haematoxylin–eosin histological analysis was supplemented with immunohistochemistry. Main outcome measures  The rate of site‐specific diagnosis. Results  A total of 149 women underwent IGB using computed tomography or ultrasound over a 6‐year period. The only complication was one rectus sheath haematoma. In 138 (93%) women, a site‐specific cancer diagnosis was made on the IGB (including 111 müllerian tract, 8 gastrointestinal tract, 4 breast and 3 lymphoma); in ten women, a repeat biopsy was necessary, giving an overall failure rate of 7%. In a further six women, malignancy was confirmed but a site‐specific diagnosis could not be made, and in four women, biopsy showed benign tissue. A site‐specific diagnosis was obtained in 29 of the 32 women (94%) with previous malignancy, of which 18/32 (56%) showed a new primary cancer. Conclusions  IGB is a safe and accurate technique for providing site‐specific diagnoses in women with PC in routine clinical practice, including those with a previous relevant malignancy. IGB can replace laparoscopic or open biopsy in defining primary therapeutic options. The data would suggest that the biopsy should be performed with ultrasound where feasible.