Management of Intra-pelvic Masses

Intra-pelvic masses are rare in dogs and cats and in the literature there are only few case reports. According to Spector et al. (2010), a mass is defined as intra-pelvic if >50 % of its long axis is caudal to the pubis and/or cranial to the caudal margin of the obturator foramen.

Clinical signs are variable and may depend on the dimension of the mass. The presence of a space- occupying lesion in the pelvic cavity may lead to deviation or compression of adjacent anatomical structures with secondary symptoms such as dischezia, fecal tenesmus, haematochezia, dysuria, stranguria, haematuria vaginal bleeding, perineal swelling, or in some cases lameness and oedema of the hind limbs.

Rectal palpation turns out to be of great aid in pre- operative evaluation as it allows identifying abnormal structures which can be more or less consistent in texture, smooth or lobulated, dorsal or ventral to the rectum and potentially rectal stricture or deviations. However, not all intra-pelvic masses are palpable at rectal examination. During digital rectal examination the sublumbar lymph nodes are palpated. These include all lymph centres present in the sublumbar region: the medial iliac, hypogastric, and sacral lymph nodes which drain the anus, rectum and colon.

Caudal abdominal radiographs generally detect the presence of intra-pelvic masses clinically suspected even though do not identify the tissue they originate from. CT and MRI scans help to properly recognize the organ of origin and can therefore provide information important in the surgical planning (Murgia, 2011).

CT and MRI scans reveal characteristics that point us toward the correct treatment plan to pursue. Information gained with cross-sectional imaging include the size, consistency (solid or cystic mass), homogeneity/ heterogeneity, the appearance of the margins (regular or irregular), contrast uptake, calcification and invasiveness into the surrounding tissues.  [...]