Case Study

CT Anal Gland Carcinoma and Reactive Lymph Node Hyperplasia in a 10 year old MN DSH cat

Right sided anal gland adenocarcinoma. Investigating for enlarged sublumbar Lymph node for metastasis. History of right anal gland mass growth within the last 2 weeks. Physical Exam: Right anal gland has multilobulated mass, about 7cm diameter CBC: All WNL Chemistry: Mildly elevated ALP, rest WNL. Normal Ca and Ionized Ca.

DX

The findings are compatible with the known anal gland adenocarcinoma. The CT study supports the presence of right-sided reactive lymph node hyperplasia. There is a moderate degenerative lumbosacral and neuroforaminal (L>>R) stenosis with moderate signs of compressive neuropathy. The relevance of the findings depends on the presence of clinical signs. Moreover there is mild bilateral coxarthrosis which likely is an incidental finding.

Image Interpretation

CT of the pelvic cavity, plain and post contrast – There was a large infiltrative ovoid soft tissue attenuating mass exhibiting non uniform contrast enhancement emerging from the right anal sac compatible with the known anal gland adenocarcinoma.
The right medial iliac and hypogastric lymph nodes showed mild enlargement. The short to long axis ratio (< 0.5) of the lymph nodes and their regular contrast enhancement pattern was preserved. There was a moderate degenerative lumbosacral stenosis with moderate disc protrusion and spondylosis deformans resulting in moderate narrowing of the vertebral canal and lumbosacral neuroforamina (L>>R). The Cauda equina nerve roots were displaced dorsally. Only a very thin layer of epidural fat signal was maintained outlining the dorsal aspect of the vertebral canal.
There was mid bilateral osteoarthritis of the hip joints as a sequel to mild hip dysplasia.
There were no bony changes compatible with metastatic spread.

Outcome

Signs specific for a secondary neoplastic infiltrate are not developed currently. Still, an emerging neoplastic infiltrate on a microscopic level cannot be ruled out.
Therefore, surgery to excise the primary tumor should be accompanied by resection of the tributary lymph nodes within the hypogastrium.