This 11 year old MN Border Collie dog has a history of high grade soft tissue sarcoma. Evaluating feasibility of hemipelvectomy to eradicate disease
This 11 year old MN Border Collie dog has a history of high grade soft tissue sarcoma. Evaluating feasibility of hemipelvectomy to eradicate disease
CT of the pelvis, abdomen and thorax, plain and post contrast – There is a large, elongated, soft tissue, attenuating, heterogeneous mass lesion in the
left femoral biceps region expanding the entire soft tissue caudal to the left femur. The
mass lesion measures more than 15 cm in length and 10 cm in depth. The proximal
origin is immediately adjacent to the pelvic symphysis and ischial bone. The muscular
midline is shifted, but not actually crossed. The right hemipelvis is not affected.
However, there is a mass effect on the pelvic, penile urethra, and cavernous body.
After administration of iodinated contrast media there is marked non-uniform
enhancement noted throughout the lesion. The lesion margins are ill-defined. There
are no bony changes associated with this lesion. Incidental metaplasia within the distal
insertion of the psoas minor muscle next to the minor trochanter of the left femur is
noted as well as incidental mild lumbar spondylosis, both of which not associated with
the soft tissue mass lesion.
The left superficial inguinal lymph node as well as the hypogastric lymph nodes are
within normal limits.
A 1.7 cm left adrenal gland nodule is noted, no vascular invasion is appreciated on the
CT study. Incidental small uncomplicated cortical renal cysts are noted.
An ill-defined soft tissue attenuating and heterogeneously enhancing mass lesion is
noted at the cardiac base on the left side level with the aortic bulb. The lesion
measures approximately 5 cm in diameter. There is a significant mass effect noted
onto the trachea, which is displaced to the right side as well as onto the left main stem
bronchi and the adjacent lung parenchyma, which reveals region of atelectasis. A mild
amount of pericardial effusion is noted. The pulmonary parenchyma is negative for metastatic spread. However, there is marked symmetric enlargement and rounding of
the sternal lymph nodes at a diameter of approximately 2.5 cm. Cranial mediastinal and
tracheobronchial lymph nodes reveal mild symmetric enlargement with heterogeneous
contrast enhancement.
The additional findings may be associated with the primary tumor such as multicentric
appearance or metastatic spread of a soft tissue sarcoma/hemangiosarcoma or be an
expression of another malignancy being present in parallel. The overall prognosis is
poor.
Regarding the original question left-sided hemipelvectomy appears to enable full
tumor resection, but neither the safety margins can be implemented as advised in highgrade
soft tissue sarcoma without affecting critical structures such as the pelvic and
penile urethra nor does the poor overall prognosis owing to the additional findings
render this a reasonable clinical decision.
In case final diagnosis and full tumor staging is strived, ultrasound guided sampling of
the sternal lymph nodes and pericardial fluid may be attempted, but the clinical impact
is limited unfortunately. Consider palliative treatment options such as chemotherapy
depending on the owner’s will.
