Sonographic Findings of Colonic Carcinoma with Regional Lymph Node Metastasis: A Case of the Month March 2022

Patient Information:

Age: 10 years
Gender: Spayed Female
Species: Feline
Breed: DSH

History:

An abdominal ultrasound was recommended due to a one month history of persistent soft stool and hematochezia. No vomiting or changes in appetite were noted by the owner. Patient was treated with metronidazole with no significant improvement. Patient also has a history of Grade II/VI murmur.

Image Interpretation:

Abdominal sonographic findings

Segments of jejunum are prominent and mildly thickened measuring 2.7 to 3.1 mm (normal wall thickness ~2.2-2.5mm, > 2.8mm abnormal Norsworthy/Estep et. al. JAVMA, Vol 243, No. 10, November 15, 2013). Normal layer proportionality is maintained without excessive thickening of the muscularis layer.
An annular, hypoechoic, vascular mass is seen in descending colon, measuring ~ 11.1mm in wall thickness. The mass has near complete loss of wall layering distinction.
The jejunal lymph nodes are moderately to severely enlarged with rounded shape having homogenous hypoechoic echogenicity, measuring ~ 1.4cm in thickness.
Other findings include a trace amount of anechoic ascites and chronic degenerative changes to both kidneys.

Distal Colonic Mass with severe wall thickening and near complete loss of normal wall layering distinction. Fecal contents casting a shadow can be seen within the lumen.

A moderately to severely enlarged and hypoechoic jejunal lymph node. Color doppler is utilized to assess vascularity prior to fine needle biopsy.

Cytologic interpretation provided by Eastern Vet Path - Casey J. LeBlanc DVM, PhD, Diplomate, ACVP (Clinical Pathology)

Diagnosis and Sonographic Analysis:

Sedated fine needle colonic and regional lymph node biopsies were obtained for cytologic review. Both sites revealed an epithelial tumor with necrosis most consistent with metastatic Carcinoma.