Image shows lump size
+ Franco’s Fight: Beating Cancer with Surgery and Skin Graft Reconstruction
Franco is a very sweet, 4-year-old, Pomeranian cross weighing about 7 kg. He was referred to BVSC because he had a subcutaneous mass on on the distal (lower) end of his left front leg first noticed by his family about a month previously.
Franco’s primary care veterinarian had already perfomed a fine needle aspirate (FNA) and had diagnosed a mast cell tumour (MCT). The mass immediately swelled up after FNA which is not uncommon for this type of cancer due to the release of histamine and other substances from the tumour. The swelling responded very well to the anti inflammatory drug, dexamethasone. The final size of Franco’s MCT was approximately 2 x 2 x 1 cms.
While sugery is the mainstay of treatment for most MCT patients, referral was sought for Franco because his MCT was situated in an area where it would be difficult to remove with a cancer-free margin.
+ Checking for Cancer Spread (Staging)
When dealing with MCTs, it is important to ensure that the disease has not spread beyond the primary tumour. The sentinel lymph node for a MCT in this location is the caudal superficial cervical lymph node (also known as the prescapular lymph node). In Franco’s case, that lymph node had subtle enlargement compared to the other side. It is important to note that even normal sized lymph nodes can habour metastatic cancer and enlarged nodes do not always represent cancer spread. For this reason we sample the relevant lymph nodes with either FNA cytology, histopathology or both. Cancer can also spread beyond the nodes and target sites include the liver, spleen and bone marrow. In Franco’s case, thoracic radiography was performed to assess the sternal lymph nodes and an abdominal ultrasound was performed to evaluate other nodes, the spleen and the liver. This is part of the process oncologists called staging. No further cancer was detected.
+ Planning Franco’s Surgery
Because mast cell tumours often require wide margins to reduce the risk of recurrence, we planned a surgery that would remove not only the visible lump but also a 2 cm margin of healthy-looking tissue around it. This is especially important when tumours are in challenging areas like the limbs.
Removal of Franco’s MCT with wide margins would require a 2cm lateral margin and beyond the deep fascia the deep margin. The options for wound closure included bandaging for secondary intention healing, utilisation of an axial pattern flap (thoracodorsal axial pattern flap for this location), and free skin grafting. If the mass was any larger, or located more distally then wide surgical excision would not have beeen possible. If this was the case, we have the option of a combination of surgery and adjunctive radiation therapy.
The primary treatment selected for Franco definitive surgery to attain wide surgical margins, removal of caudal superficial cervical lymph node with a free skin graft reconstruction of the primary site.
Full thickness skin from his lateral thoracic region was harvested and prepared (meshed after removal of the subcutaneous tissue). This graft was sutured over the wound defect. A non-adhesive dressing was placed over the wound, and a soft padded bandage was then applied. A splint was used to prevent excessive movement of the underlying muscles and tendon during recovery. Franco went home after a comfortable night in hospital.
Over the ensuing days and weeks after surgery, Franco’s surgery site healed extremely well
(Warning – graphic images)
Dr Marvin has marked out the visible edge of the tumour and then made a circle with a surgical marking pen to guide where the skin incision will go to achieve wide margins.
To close the defect after tumour removal, Dr Marvin sutured a free skin graft in place.
He had frequent bandage changes and the splint was removed 2 weeks after his surgery. The graft was mostly healed by then, and a light bandage was placed to help protect it for another week.
Day 4
Day 32
Here is Franco’s surgery site at 7 weeks. It was completely healed without complication.
+ Looking Ahead
Franco recovered very well from his procedure with few if any significant complications and maintained good limb function. The histopathology of the resected subcutaneous MCT a low grade type excised with complete margins. There was, however, evidence of early metastasis to the caudal superficial cervical lymph node. Adjunctive chemotherapy was recommended to address the theoretical presence of undetectable cancer cells beyond the resected local lymph node.
Franco is doing brilliantly after his surgery. His family is keeping up with regular and important check-ups to ensure everything continues to go smoothly. We’re so proud of how brave he’s been and grateful to his referring vet and his family for trusting us with his care.
If your pet has been diagnosed with a mast cell tumour or you’ve noticed an unusual lump, don’t hesitate to reach out. Early diagnosis and the right treatment plan can make all the difference. BVSC is here to help every step of the way.
