This is a slow-growing tumor until malignant transformation occurs.
- In the salivary gland, HER2/neu overactivity has been observed with malignant transformation carcinoma ex pleomorphic adenoma, therefore HER2 based therapy might be effective when medical treatment is needed (Sharon 2010). It has not yet been studied in orbital tumors.
- Trastuzumab (Herceptin) is a monoclonal antibody that competitively binds to the plasma membrane HER2 receptor.
Cases of multinodular recurrent benign pleomorphic adenoma can be treated with radiotherapy, in addition to surgery or if surgical excision is impractical.
Although excisional biopsy is the accepted standard of care there are advocates of limited preliminary biopsy prior to excision to confirm the diagnosis (Lai 2009).
- The theory behind incisional biopsy is that management can be changed by recognizing an alternative diagnosis.
- Incisional biopsy might be most appropriate when the lesion is not amenable to simple removal, without affecting tissues other than the lacrimal gland.
Figure 2. Bone flap for pleomorphic adenoma. Courtesy Robert G. Fante, MD, FACS.
Figure 3. Bone flap replaced. Courtesy Robert G. Fante, MD, FACS.
Other management considerations
- Secondary excision if tumor has been left behind focuses similarly on dissection along the encapsulated surface
- Wide tumor free margins might be needed to assure complete excision and avoid malignant transformation.
Common treatment responses, follow-up strategies
Once complete excision has been accomplished with the capsule intact, there should be no risk of continued tumor growth.