11/4 - Mast Cell Tumors

Mast Cell

What tumors usually have variable appearance, can be dermal or SC, and tend to wax and wane? 10% will have multiple nodules. There will be round cells containing basophilic granules. H1 receptor activation will cause local irritation, Darier’s sign, and hypotension. H2 activation will cause GI ulceration. Diagnosis can involve cytology, LN FNA, and grading. PPI or H2 blockers can be used if there is a large burden. Staging and biopsy may be indicated before definitive therapy. Local disease control is with excision with full margins. Grading can be done with 2 or 3 tiers.

No

While Ki67 (number of dividing cells) and AgNOR (division speed) panels can be done, they are only done if it will change your recommendations. Will this predict response to therapy?

0-3

What scale is used for lymph node involvement/metastasis in mast cell tumors? HN3 is a negative prognostic factor. 1 and 2 can be treated with local control.

Aspirate

Staging of dermal mast cell tumors is based on what test on a local LN? This is only when there are negative prognostic factors. Post-op therapy involves monitoring complete margin excision and offering other treatments for dirty margins. Full staging involves LN, AUS, liver/spleen.

Vinblastine, Prednisone

What two drugs can be given post-op to mast cell tumor removal? The MST is 3.7 years in high-risk tumors and involves 8 treatments over 12 weeks, and survival is 70% at 2 years post-op. Toceranib/Palladia can also be given orally but can cause neutropenia, GI/renal toxicity.

Electrochemotherapy

What treatment technique can be done to non-surgical mast cell tumors, and involves short anesthesia, IV bleomycin, electroporation, and usually 2 treatments?

Yes

Can stelfonta/tigilanol be given to mast cell tumors to cause rapid tissue inflammation and necrosis for non-metastatic and non-operable mast cell tumors?

No

Does feline MCT have any association with FeLV, FIV, or FIP? They can be cutaneous, splenic/visceral, or intestinal. The spleen version has 12-19 months MST and the current recommendation is only with surgery. There is common metastasis with splenic MCT. There is usually poor prognosis.