35 - Soft Tissue Masses Flashcards
Goals of tumor management
- Identify lesion
- Rule out malignancy
- Relieve pain
- Prevent growth or spread (limit local destruction)
- Cosmetic improvement
Tumor
- General morphologic term for any abnormal mass
- Does not define benign vs. malignant
- “Soft Tissue” does not include epithelial tissue however there is such a great overlap in evaluation and management in this presentation epithelial factors and conditions will be included
- Tumor just means a growth – to a patient, a tumor means cancer, so be careful
- Both are just skin tags (acral cordon) – all others except bottom left
- Bottom left is an amelanotic melanoma
Overview of soft tissue tumors
- Over 80 distinct soft tissue tumor types
- 100:1 ratio of benign to malignant STM
- Most Common = Ganglion and fibroma (Benign) and Synovial sarcoma (Malignant)
- Higher frequency of malignancy in the hind-foot
- Early recognition common in the foot because of local prominence
- There is clinical feature overlap between STM, dermatologic conditions and ulcerations
Classification system of soft tissue mass (STM)
Histologic type
o Cell type
o Germ layer
Biologic behavior
o Benign
o Malignant
Anatomic site
o Localized
o Widespread
Benign tumor staging
- Stage 1 = latent, not growing
- Stage 2 = active, enlarging but not invading, pushing tissues out of the way, entwining within them
- Stage 3 = aggressive, invade other structures
Cellular changes
- Hyperplasia (just more cells)
- Metaplasia (one cell turns into different cell)
- Dysplasia (disordered growth)
- Neoplasia (new growth)
Factors influencing cell activity
- Mechanical
- Inflammatory
- Infectious
- Metabolic
- Genetic
Morton’s neuroma
- Example: 3rd interspace, deep transverse intermetatarsal ligament
- Example: Ankle fracture where they partially nicked the nerve – scar tissue formation – NOT NEW GROWTH, just a neuroma
Benign neoplasm
o Named by adding “- oma” to the parenchymal cell type
o Both for cells of epithelial or mesenchymal origin
o Most are single cell origin
Malignant neoplasm
o “Carcinoma” if epithelial in origin
o “Sarcoma” if mesenchymal in origin
Diagnosis of a soft tissue mass
- History
- Clinical Characteristics
- Imaging
- Biopsy
- CANNOT make a diagnosis by imaging – THE ONLY WAY TO DIAGNOSE IS BY BIOPSY***
Clinical features of a soft tissue mass to look for
- Size
- Shape
- Texture
- Location
- Mobility
- Color
- Pain
- Temperature
- Pulse / Bruit
- Parathesia
Diagnostic imaging modalities for soft tissue masses
- X-ray
- CT
- Bone scan
- MRI
Use of X-ray to assess soft tissue mass
o Calcification
o Bone Tumor simulating STM
o Bone invasion
Use of CT to assess soft tissue mass
o Location, Size, Bone invasion
Use of MRI to assess soft tissue mass
o Anatomic localization
o Relative tissue type
o Does not provide a definitive diagnosis
Biopsy
- Most important method of identification for tumors
- Provides vital information for prognosis and treatment
- Excisional biopsy may provide “cure”
- ***MOST IMPORTANT THING IS BIOPSY – need to know what you are looking for
Biopsy types
*THIS IS IMPORTANT
- Closed biopsy
- Incisional biopsy
- Excisional biopsy
Closed biopsy
o Needle aspiration
o Core Biopsy
Incisional biopsy
o Wedge
o Punch
o Shave
Excisional biopsy
o Marginal
o Wide local
o Radical (TAKE OUT ENTIRE COMPARTMENT***)
Lesions that should be biopsied
- Fast growing
- Inflamed or ulcerated
- Large masses
- Painful, pruritic and otherwise symptomatic
- Ulcerations present for greater than 4 weeks
- Non responsive to treatment
- Pigmented Lesions
- If there is no other reason for it to be ulcerated, ALWAYS BIOPSY IT
Incision location
- Direct access to the tumor
- Do not cross compartments
- Consider the local anatomy
- Consider subsequent care
Clinical considerations for biopsy
- When determining incision location, consider access to mass, how to protect local anatomy, and plan for future excision if necessary
- When dissecting tissue, determine normal or abnormal
- Remove tissue so that we may achieve accuracy of pathology
- Consider tissue planes and possible spread of tumor cells
Tissue removal
- Representative sample
- Adequate amount
- Avoid frankly necrotic tissue
- Advancing edge?
- If possible, excisional biopsy is best
Compare incisional vs excisional biopsy
TEST QUESTION
Excisional biopsy preferred
o Diagnosis & Cure
o One procedure
Incisional best if
o Complicated anatomy
o Clinical suspicion of malignancy
o Large lesion (can’t do an excisional)
Types of excision
TEST QUESTION
- Intra-capsular Excision
- Marginal Excision
- Wide Local Excision
- Radical Resection
Intra-capsular Excision
o Excision within tumor capsule or margins
o De-bulking
o You’re not even taking the whole tumor, just “de-bulking it”
Marginal Excision
o Excision of entire tumor and capsule with minimal normal tissue
Wide Local Excision
o Excision of tumor and cuff of normal tissue
Radical Resection
o Removal of entire anatomic compartment
Incision location
- Direct access to the tumor
- Do not cross compartments
- Consider the local anatomy
- Consider subsequent care
Neurofibromatosis
- Neurofibromatosis – just wanted to do an intracapsular incision (de-bulk it) in order to prevent the nerve compression and relieve pain
Mucocutaneous cyst
- Related to ganglion cyst (mucoid cyst)
- This is a mucocutaneous cyst, which is another type of mucoid cyst
- Would have a thick gel fluid in it, just like in a ganglion cyst
Example of plantar tumor
- There is tumor everywhere
- Need incision that allows you to get to everything
- Widely invasive into the tissues – This is an intracapsular incision
- Wide local incision – had to take a lot of tissue to get as much of it as you can so it doesn’t recur
Example of tumor on hallux
- Hard to get to both sides of the hallux
- Need to design an incision that allows you to get to all sides of the hallux
- This was putting pressure on the nerves underneath
- INVADES tissue – no capsule, no separation of the vital structures
- Had to take out a lot
- Need to start from where you can see normal tissue
Example of BAD approach
- VERY BAD APPROACH – Need a wide marginal incision (this is very small)
- You can’t see any anatomy
- They will have multiple recurrences and an ugly scar already
- Need to open it up to the extent of the lesion
Dermafibroma
- Skin is hard to close on the toes because there is not an excess of tissue – this approach saves 60% of tissue
Pathology analysis of specimen
- Formalin fixed
- Frozen section
- Culture media
- Aerobic, anerobic, fungal, acid fast
Fomalin fixed
o When you take it out, you need to send it to pathology – most tumors will go in formalin
o If you’re trying to get a culture, DO NOT put it in formalin (kills bacteria)
o If you are trying to test for gout, DO NOT put it in formalin (dissolves it)
Frozen section
o Identify need for immediate further treatment
o They may be able to tell you if it is malignant or not
Goals of biopsy
- Determine histologic type and grade of tumor
- Determine the anatomic extent of the tumor
- Determine prognosis and establish further treatment
Properties of benign tumors
*TEST QUESTION
o Well differentiated o Normochromatic o Rare mitoses o Cells retain normal function o Encapsulated o Push local structures aside
Properties of malignant tumors
TEST QUESTION
o Anaplastic o Pleomorphic o Hyperchromatic o Mitoses common o Normal function lost o Invade local structures
Staging of malignant tumors
- Grade (G)
- Anatomic site and extent (T)
- Metastasis (M)
- Used to predict prognosis, choose treatment, predict response to treatment and recurrence
Notes:
o Not going to belabor a lot of this, but these factors are used to predict prognosis
o We will always work with an oncologist or a surgeon that is experienced with melanoma and they usually do the staging, we will just do the local treatment of it
o You do need to understand what goes into the prognosis
Lesions NOT to miss
- Pigmented Lesions
- High index of suspicion for malignancy
o Large and/or fast growing
o Associated with ulceration
o Painful - Biopsy, Biopsy, Biopsy
- If there is NO OTHER REASON for the patient to have an ulcer, you NEED TO BIOPSY it
REVIEW
- Biopsy is the only definitive way to diagnose a STM
- Excisional biopsy is preferred if possible
- Carefully consider approach to excision to avoid unnecessary damage or spread
- Must have a low threshold for biopsy of suspicious lesions
