ג'וש מצגת 1 - Flashcards
General Approach to the Diagnosis andStaging of Skin Tumors
History and general physical examination Minimum data base Tumor staging: Assessment of the cutaneous mass (physical examination of the mass) Cytology Biopsy Regional lymph node assessment Preoperative diagnostic imaging
The two most common malignant skin tumours in dogs
mast cell tumours (MCTs) and soft tissue sarcomas (STSs), occur relatively commonly on the distal extremities of dogs.
it is generally recommended that grade II MCTs be excised with 2cm lateral margins and STSs with 3cm lateral margins.
משפטי ג’וש
If you can’t go deep, don’t go wide!
In general, the simplest technique should be selected for reconstruction of large skin defects that cannot be closed primarily
skin grafting
skin grafting immediately following tumour resection
potentially increases the risk of haematoma development between the wound and skin decreasing graft survival
or waiting 3-5 days until a healthy granulation tissue bed has developed.
Halstead’s principles
Strict asepsis during preparation and surgery.
Good hemostasis to improve conditions for the procedure and limit infection and dead space.
Minimize tissue trauma.
Use good surgical judgment ensuring elimination of dead space and adequate removal of material.
Minimize surgery time through knowledge of anatomy and technique.
Correct use of instruments and materials
First principle of surgical oncology
The first attempt is the best chance for LOCAL TUMOR CONTROL
An incomplete excision is considered to contaminate the entire surgical field.
Second attempt has to be wider and deeper to control the disease process locally.
Presence of scar tissue complicates the surgery.
Surgical doses are customarily defined as
Intracapsular
marginal
wide
radical
Intracapsular
Debulking or cytoreductive
Macroscopic volumes of tumor left behind
Local recurrence is ensured unless followed by radiation or other adjuvant therapy
Adjuvent therapy is generally less effective when grossly visible tumor is left behind
marginal
Excsion immediately outside the pseudocapsule
Microscopic volumes of tumor left behind
Local recurrence likely without adjuvant therapy
wide
Removal of tumor with normal tissue in all directions
Local recurrence unlikely
radical
Removal of the entire anatomical structure or compartment containing the tumor
Local recurrence is unlikely
מניעת גידולי עטין
Ovariohysterectomy, dramatically reduces the risk of mammary tumors in both dogs and cats
Preoperative assessment of the cancer patient
What is it?
Where is it?
What is the status of the patient?
Cytology
Cytology is appropriate for any palpable, external mass and can be applied to body cavity masses using image guidance.
A sample for cytology can be obtained using a fine gauge needle (20 to 25 gauge) inserted into the mass and redirected multiple times by partially withdrawing (not exiting skin) and reinserting.
The goal of fine-needle aspiration is to differentiate between an inflammatory or neoplastic process, and if neoplastic, whether the tumor is benign or malignant.
The accuracy of a fine-needle aspirate depends on many factors, including the tumor type, location, and amount of inflammation.
Overall sensitivity and specificity of cytology has been reported to be 89% and 100%, respectively
שאלה ממבחן
4 אסטרטגיות בניהול גידול עור ממאיר בגפה דיסטאלית
- marginal excision וסגירה מיידית של העור
סיכון גבוה לחזרתיות.
2margina excision בשילוב עם הקרנות
יעיל מאוד אבל לא זמין
3.אמפוטציה - קשה לבעלים
4.marginal/wide excision and second intenetion healing
טיפול אפקטיבי
5.wide excision with reconstruction
flaps, grafts, mesh
שאלה ממבחן
דוגמאות לגידולים שניתן למנוע ע”י פרוצדורות כירוגיות
כלבות שעברו עיקור לפני ייחום ראשון אחר אחרי הורידו את הסיכוי לגידולי עטין ב0.5 ו8^ בהתאמה.
חתולות לא מעוקרות בעלות סיכוי פי 7 לגידולי עטין
כלבים שאינם מסורסים בעלי סיכון גבוה בהרבה ל
perianal adenoma/adenocarcinoma/
Surgery may also be performed to correct congenital anatomical abnormalities that may predispose to neoplasia.
The best example is removal of cryptorchid testicles.
Surgical Palliation
The goal of palliative surgery is to control clinical signs and, if possible, prolong life.
cessation of hemorrhage, pain, or paraneoplastic signs; and treatment of obstruction or perforation
SKELETAL SARCOMAS
- ENDOPROSTHESIS - פרוסטזה מתכתית לאחר הסרת הגידול, אין תהליך ריפוי ואינטגרציה של הפרוטזה לרקמה, לאורך זמן יהיה שחרור של התיקון.
2.ALLOGRAFT
השתלת שתל עצם מכלב אחר, לא דווח על החלמה ואיחוי לשתל
3.INTRAOPERATIVE EXTRACORPOREAL IRADIATION
הוצאת העצם עם הגידול והקרנות ואז החזרה- העצם פגעה.
4.distal aspect of the ulna transposition autograft
כנראה השיטה הכי יעילה, הזזת האולנה ואספקת הדם שלה במקום הרדיוס בתופסת פלטה.
5.BONE TREANSPORT
הסרת החלק עם הגידול ובשילוב עם טבעות פרוקסימליות ודיסטליות לקרב בהדרגה את החלקים הנותרים
Preoperative Evaluation before STS
הערכה לפני ניתוח להסרת STS
Fine needle aspiration
Cytology is often unrewarding as their connective tissue nature does not result in cell shedding in large numbers.
Evaluation in cases of suspected STS ultimately involves a biopsy to confirm the diagnosis and histologic grade (differentiated vs undifferentiated)
A wedge biopsy is preferred to obtain adequate tissue for histologic assessment
Excisional biopsy should be considered only for very small lesions, on the trunk only, when STS is suspected