Читать книгу Veterinary Surgical Oncology - Группа авторов - Страница 24

The approach to an excisional biopsy is variable based on location, goal of surgery, and predetermined adjuvant therapy. An excisional biopsy has the advantage of being both a diagnostic technique as well as a treatment modality. A great deal of caution should be exercised in cases where the diagnosis is unclear. At a minimum, an FNA should be obtained to discern if a given mass is inflammatory or neoplastic and, if neoplastic, whether benign or malignant. This information is imperative in order to determine surgical dose.

There are cases where an excisional biopsy may be a reasonable option, if doubt or absence of knowledge of the tumor type remains after fine needle aspiration (e.g. nondiagnostic results from cytology), depending on the size and location of the tumor. In these instances, the surgeon must contemplate if an excisional biopsy will compromise the ability to enact a cure by wide excision. If it is deemed that an excisional biopsy can be performed while leaving this option, an excisional biopsy can be considered. For example, a 1 cm in diameter mass on the trunk of a large breed dog can be interrogated by excisional biopsy, whereas a 1 cm in diameter mass on the distal extremity of a dog should be interrogated by incisional biopsy (wedge or punch).

Once an excision is performed, the local anatomy is forever altered, tissue planes both deep and wide to the tumor are invaded, providing an opportunity for the tumor cells to extend and seed deeper and wider into tissues. For this reason, the best chance for complete excision is at the time of the first surgical excision. In order to perform a curative surgery, the surgeon must take the appropriate margin of tissue for the tumor type. In some cases (lipoma), this margin is minimal or even intralesional. In other cases (soft tissue sarcoma), the margin should be more extensive. Unless the tumor type is known at the time of excision, the surgeon may compromise the patient by doing too little or too much surgery.