# Clinical Cases: Surgical Oncology

## Case 1: Melanoma

### Patient Demographics
- **Age:** 52 years
- **Sex:** Male
- **Occupation:** Golf course manager

### Chief Complaint
"I noticed a dark mole on my back that has changed over the past several months."

### History of Present Illness
The patient's wife noticed a pigmented lesion on his upper back that has been changing over the past 4-5 months. It has become darker, larger, and has developed irregular borders. The patient has had significant sun exposure throughout his life due to his occupation and recreational activities. He has had multiple blistering sunburns in the past. He has not had any prior skin cancers. He has noticed no other changing lesions and has no systemic symptoms.

### Past Medical History
- Hypertension
- Hyperlipidemia
- No prior skin cancers
- Multiple blistering sunburns as youth

### Family History
- Father: Melanoma at age 65 (survived after surgery)
- Mother: Basal cell carcinoma

### Physical Examination
- **General:** Well-appearing male with fair complexion, multiple nevi
- **Back:** 1.8 cm asymmetric, darkly pigmented lesion with irregular borders and color variation (brown, black, red areas), raised surface
- **Full skin exam:** No other suspicious lesions
- **Lymph nodes:** No palpable cervical, axillary, or inguinal adenopathy

### ABCDE Assessment
- **A**symmetry: Present
- **B**order irregularity: Present
- **C**olor variation: Multiple colors present
- **D**iameter: >6 mm (1.8 cm)
- **E**volving: Yes (per history)

**Highly suspicious for melanoma**

### Initial Management
- **Excisional biopsy** performed (full-thickness, 1-2 mm margins)
- Shave biopsy avoided (need full thickness for staging)

### Pathology Results
- **Diagnosis:** Invasive melanoma
- **Breslow thickness:** 2.4 mm
- **Ulceration:** Present
- **Mitotic rate:** 4/mm²
- **Margins:** Positive (biopsy margins)
- **Clark level:** IV (reticular dermis)

### AJCC Staging (8th Edition)
- T stage: T3b (2.01-4.0 mm with ulceration)
- Need SLN biopsy for nodal staging

### Staging Workup
**Sentinel lymph node biopsy (SLNB) indications:**
- Breslow >0.8 mm OR
- Breslow <0.8 mm with adverse features (ulceration, high mitotic rate)
- This patient: 2.4 mm, ulcerated → SLNB indicated

### Imaging
- CT Chest/Abdomen/Pelvis: No evidence of distant metastases
- PET-CT: May be considered for higher-stage disease

### Definitive Surgical Management
**Wide local excision + Sentinel lymph node biopsy:**
- Wide excision with 2 cm margins (for T3 disease)
- Preoperative lymphoscintigraphy: Drainage to left axilla
- SLN biopsy: Left axilla
- Primary closure of back wound

### Pathology Results - Final
- Wide excision margins: Negative
- Sentinel lymph nodes: 2 nodes identified
  - Node 1: Metastatic melanoma (1.2 mm deposit)
  - Node 2: Negative
- **Stage IIIB** (T3bN1aM0)

### Multidisciplinary Tumor Board Discussion
- Stage IIIB melanoma with positive sentinel node
- Options discussed:
  1. Completion lymph node dissection (CLND) - no longer standard
  2. Surveillance with imaging
  3. Adjuvant systemic therapy

**Based on MSLT-II trial:** CLND does not improve survival in SLN-positive patients who will receive adjuvant therapy

### Adjuvant Therapy
**Options for Stage III melanoma:**
1. **PD-1 inhibitors:** Pembrolizumab or Nivolumab (preferred)
2. **BRAF/MEK inhibitors:** If BRAF mutation positive (dabrafenib/trametinib)

**Molecular testing:**
- BRAF mutation: V600E positive

**Treatment decision:**
- Pembrolizumab (1 year) chosen
- Alternative would be dabrafenib/trametinib combination

### Follow-up Schedule
- Clinical exam every 3-6 months for 2 years, then every 6-12 months
- CT imaging every 6-12 months for first 2-3 years
- Patient education on skin self-exam
- Annual full-body skin exam by dermatologist

### Teaching Points
1. ABCDE criteria help identify suspicious lesions
2. Breslow thickness is the most important prognostic factor
3. Excisional biopsy preferred over shave for accurate staging
4. Sentinel lymph node biopsy for staging intermediate/thick melanomas
5. Wide excision margins based on Breslow depth
6. CLND no longer standard for positive SLN with adjuvant therapy available
7. Adjuvant immunotherapy improves survival in Stage III melanoma

### Clinical Image
![Melanoma Clinical Image](case_01_image.jpg)

**Image Description:** Clinical photograph of a melanoma demonstrating the ABCDE criteria: Asymmetry, Border irregularity, Color variation with multiple shades of brown, black, and red, Diameter greater than 6 mm, and history of Evolution over time.

**Attribution:** Image from Wikimedia Commons, Category:Melanoma. Source: https://commons.wikimedia.org/wiki/Category:Melanoma

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## Case 2: Soft Tissue Sarcoma

### Patient Demographics
- **Age:** 45 years
- **Sex:** Female
- **Occupation:** Physical therapist

### Chief Complaint
"I noticed a lump in my thigh that has been growing over the past few months."

### History of Present Illness
The patient first noticed a mass in her right anterior thigh approximately 4 months ago. Initially, she thought it was a muscle strain from exercise. However, the mass has been gradually enlarging and is now easily palpable. It is deep-seated, firm, and only mildly uncomfortable. She has no history of trauma to the area. She denies fever, weight loss, or other constitutional symptoms.

### Past Medical History
- No significant medical history
- No prior cancers
- No radiation exposure

### Physical Examination
- **General:** Well-appearing female
- **Right thigh:**
  - 8 cm firm, deep-seated mass in anterior thigh
  - Fixed to underlying structures
  - Non-tender
  - No overlying skin changes
  - No inguinal lymphadenopathy
- **Neurovascular:** Intact distally

### Clinical Suspicion
**Red flags for soft tissue sarcoma:**
- Size >5 cm
- Deep location (below fascia)
- Growing mass
- Fixed to underlying tissue

### Imaging Workup

**MRI Right Thigh:**
- 9.2 x 7.5 x 6.8 cm heterogeneous mass
- Located deep to fascia within quadriceps muscle compartment
- T1: Intermediate signal
- T2: Heterogeneous high signal
- Enhancement: Peripheral and heterogeneous
- No involvement of femur
- Relationship to femoral vessels: Close but distinct

### Imaging for Staging
**CT Chest:** No pulmonary metastases (lungs are most common site of sarcoma metastasis)

### Tissue Diagnosis
**Core needle biopsy** (preferred over open biopsy when possible):
- Approach: Through muscle belly that would be excised with tumor
- Result: High-grade pleomorphic sarcoma
- Immunohistochemistry: MDM2 amplification negative, non-specific markers
- Final diagnosis: **Undifferentiated pleomorphic sarcoma (UPS)**, high-grade

### Staging
- Tumor size: >10 cm → T3
- Grade: High (Grade 3)
- Nodes: N0
- Metastasis: M0
- **Stage III** (T3 N0 M0, high-grade)

### Multidisciplinary Tumor Board
- High-grade soft tissue sarcoma of thigh
- Close to neurovascular structures
- Options:
  1. Upfront surgery with adjuvant radiation
  2. Neoadjuvant radiation followed by surgery

**Decision:** Neoadjuvant radiation preferred (larger field but lower dose, fewer wound complications than adjuvant radiation in extremity STS)

### Neoadjuvant Radiation Therapy
- 50 Gy in 25 fractions over 5 weeks
- MRI post-treatment: Stable size with some internal changes

### Surgical Management (4-6 weeks after radiation)
**Wide local excision:**
- Limb-sparing surgery
- En bloc resection of tumor with surrounding cuff of normal tissue
- Margin goal: 1-2 cm or intact fascial barrier
- Femoral vessels preserved (no encasement)
- Femoral nerve preserved
- Quadriceps muscle partially resected with tumor

### Pathology
- Undifferentiated pleomorphic sarcoma, high-grade
- Size: 8.5 cm (some treatment effect)
- Margins: R0 (negative, closest margin 1.2 cm)
- Treatment response: 40% necrosis

### Postoperative Course
- Wound healing delayed (expected with neoadjuvant radiation)
- Wound VAC therapy for 2 weeks
- Secondary closure achieved
- Physical therapy for quadriceps strengthening

### Adjuvant Therapy
- No adjuvant chemotherapy given (role in STS is limited, controversial for most subtypes)
- Surveillance imaging recommended

### Surveillance Protocol
- History/physical every 3-6 months for 2-3 years, then annually
- Chest imaging (CT or X-ray) every 6 months for 2-3 years
- Local imaging (MRI) if clinically indicated
- Surveillance for 10 years (late recurrences can occur)

### Teaching Points
1. Mass >5 cm, deep location, growing = consider sarcoma
2. MRI is imaging modality of choice for extremity soft tissue masses
3. CT chest for lung staging (most common metastatic site)
4. Core biopsy preferred; if open biopsy needed, plan incision along potential resection
5. Limb-sparing surgery + radiation is standard (amputation rarely needed)
6. Neoadjuvant radiation may improve limb function, adjuvant radiation may have fewer wound issues
7. Margins and grade are most important prognostic factors

### Clinical Image
![Soft Tissue Sarcoma MRI](case_02_image.jpg)

**Image Description:** MRI of the thigh demonstrating a large, deep-seated soft tissue sarcoma within the muscle compartment. The heterogeneous signal intensity and enhancement pattern are characteristic of high-grade sarcoma.

**Attribution:** Image from Wikimedia Commons. Source: https://commons.wikimedia.org/wiki/Category:Skin_cancers

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## Case 3: Hereditary Cancer Syndrome - Lynch Syndrome

### Patient Demographics
- **Age:** 38 years
- **Sex:** Female
- **Occupation:** Elementary school teacher

### Chief Complaint
"I was told I have colon cancer, and I'm worried about my family."

### History of Present Illness
The patient presented with rectal bleeding and change in bowel habits. Colonoscopy revealed a sigmoid colon mass, and biopsy confirmed adenocarcinoma. Staging workup showed localized disease (T3N0M0). During her oncology visit, the young age of onset raised suspicion for a hereditary cancer syndrome. Detailed family history revealed multiple family members with cancer.

### Family History (Three-Generation Pedigree)
- **Patient:** Colon cancer at age 38
- **Father:** Colon cancer at age 45, currently alive
- **Paternal grandmother:** Endometrial cancer at age 52, died age 60 from "stomach cancer"
- **Paternal uncle:** Colon cancer at age 48
- **Paternal aunt:** Ovarian cancer at age 55
- **Two younger sisters:** Healthy, ages 35 and 32

### Amsterdam II Criteria Assessment
At least 3 relatives with Lynch-associated cancer:
- 1 is first-degree relative of the other 2 ✓
- At least 2 successive generations affected ✓
- At least 1 diagnosed before age 50 ✓
- FAP excluded ✓
- Tumors verified pathologically ✓

**Patient meets Amsterdam II criteria for Lynch syndrome**

### Tumor Testing
**Immunohistochemistry (IHC):**
- MLH1: Present
- MSH2: **Absent**
- MSH6: **Absent**
- PMS2: Present

**Microsatellite instability (MSI) testing:**
- MSI-High (MSI-H)

**Findings suggest:** MSH2 germline mutation likely

### Genetic Counseling and Testing
- Pre-test counseling provided
- Informed consent obtained
- **Germline genetic testing result:** Pathogenic MSH2 mutation confirmed

### Diagnosis
**Lynch Syndrome** (Hereditary Non-Polyposis Colorectal Cancer - HNPCC)
- Autosomal dominant
- MSH2 mutation
- Significantly increased risk of multiple cancers

### Cancer Risks Associated with MSH2 Mutation
| Cancer Type | Lifetime Risk | General Population |
|-------------|---------------|-------------------|
| Colorectal | 40-80% | 4-5% |
| Endometrial | 40-60% | 2.5% |
| Ovarian | 10-25% | 1.5% |
| Gastric | 6-13% | <1% |
| Urinary tract | 4-25% | <1% |
| Small bowel | 1-4% | <1% |
| Brain (Turcot) | 1-3% | <1% |

### Management of Current Cancer
**Surgical options for colon cancer in Lynch syndrome:**
1. Segmental colectomy (standard for sporadic cancer)
2. Subtotal/total colectomy (reduces metachronous cancer risk)

**Discussion with patient:**
- Risk of metachronous colorectal cancer with segmental resection: ~16% at 10 years
- Total colectomy eliminates colon cancer risk but impacts quality of life

**Patient decision:** Total abdominal colectomy with ileorectal anastomosis

### Surgery
- Total abdominal colectomy with ileorectal anastomosis
- Pathology: T3N0 (0/18 nodes), MSI-H adenocarcinoma
- Stage II with MSI-H (favorable biology)

### Adjuvant Therapy Considerations
- Stage II MSI-H colon cancer: Generally favorable prognosis
- 5-FU based chemotherapy may not benefit MSI-H tumors
- Decision: Observation without adjuvant chemotherapy

### Risk-Reducing Strategies for Patient

**Gynecologic cancers:**
- Annual pelvic exam
- Consider endometrial sampling annually starting age 30-35
- Discuss risk-reducing hysterectomy and bilateral salpingo-oophorectomy after childbearing complete
- Patient opted for surveillance initially, planned RRSO after age 40

**Remaining rectal surveillance:**
- Annual proctoscopy/sigmoidoscopy of remaining rectum
- Consider completion proctectomy if dysplasia develops

**Other cancer surveillance:**
- Upper endoscopy every 3-5 years (starting age 30-40)
- Urinalysis annually (urothelial cancer screening)
- Annual skin exam

### Cascade Genetic Testing for At-Risk Relatives
- First-degree relatives (sisters, children of affected relatives) should undergo genetic counseling and testing
- Predictive testing identifies who carries the mutation
- Allows personalized screening for mutation carriers
- Non-carriers can follow general population guidelines

### Family Testing Results
- Father: MSH2 mutation positive (known - colon cancer)
- Sister (35 y/o): MSH2 mutation positive → enhanced screening initiated
- Sister (32 y/o): MSH2 mutation negative → general population screening

### Teaching Points
1. Young age at diagnosis (<50) should prompt consideration of hereditary syndrome
2. Lynch syndrome: Most common hereditary colon cancer syndrome
3. Tumor testing (IHC, MSI) can guide germline testing
4. Amsterdam criteria and Bethesda guidelines help identify at-risk patients
5. Extended colectomy may be considered in Lynch syndrome
6. Risk-reducing surgery (hysterectomy/BSO) reduces gynecologic cancer risk
7. Cascade testing identifies at-risk family members
8. MSI-H tumors may respond to immunotherapy in advanced/metastatic setting

### Clinical Image
![Lynch Syndrome Pedigree](case_03_image.jpg)

**Image Description:** Three-generation family pedigree demonstrating the autosomal dominant inheritance pattern of Lynch syndrome. Multiple family members are affected with Lynch-associated cancers including colorectal, endometrial, and ovarian cancers at young ages.

**Attribution:** Image from Wikimedia Commons, Category:Colorectal cancer. Source: https://commons.wikimedia.org/wiki/Category:Colorectal_cancer