Soft Tissue Review for PGH Interns 2020 - PowerPoint Presentation

1. Soft Tissue Review for PGH Interns 2020Shiela S. Macalindong, MD, FPCS, FACSClinical Associate ProfessorDivision of Surgical Oncology, Head and Neck, Breast, Skin & Soft Tissue, and Esophagogastric Surgery

2. SOFT TISSUE MASSESMost are benignMasquerades of soft tissues masses : lymph nodes, cystic masses of the neck, hernias, parotid tumorFavor BenignFavor MalignantSlow-growing>5 cm tumorsMultipleDeep in locationPainful/tenderFixedNeurovascular deficit

3. Epidermoid cyst/Epidermal inclusion cyst:Sebaceous cyst a misnomerMay rupture or get infectedTx: Observation or excision (include punctum and entire capsule)LipomaTx: Excision or observationHemangiomaSubcutaneous nodule/mass with overlying bluish or reddish hue to the skin

4. Soft Tissue SarcomaRare, diverse group of >60 neoplasmsOriginate from cells of mesodermal origin Spectrum of clinical behavior : indolent to aggressiveExtremities (60%), trunk (25%), pelvis/retroperitoneumTrunk and extremity sarcoma vs. intraperitoneal/retroperitoneal sarcomasMost common subtype of extremity STS: undifferentiated pleiomorphic sarcoma (previously called malignant fibrous histiocytomaMost common retroperitoneal STS: liposarcoma

5. Soft Tissue SarcomaMost are sporadicDon’t arise from progression/de-differentiation of benign lesionsRisk factors :EBRT Chemicals: phenoxyacetic acid, chlorphenols, Angiosarcomas: thorium oxide, vinyl chlorideChronic lymphedema – Stewart-Treves SyndromeGenetic syndromes – LiFraumeni (sarcomas), NF1 (MPNST), FAP (desmoid tumors)

6. Soft Tissue SarcomaExtremity: painless massRetroperitoneum: abdominal fullness, early satiety, abdominal/flank pain, palpable mass (less common)PE: Extremity: size, depth in relation to muscle/fascia/bone, mobility/fixation, involvement of neurovascular structuresRetroperitoneal: neurovascular status of extremity, lymphatic and GU exam (hematologic, testicular, gynecologic malignancies)Rare LN mets (<5%) except for: synovial sarcoma, vascular sarcomas, rhabdomyosarcoma, epithelioid and clear cell sarcomaHematogenous spread: Extremity STS: Lungs; Retroperitoneal sarcoma: Lungs/Liver

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8. Soft Tissue SarcomaPrognostic factorsTumor gradeTumor sizeTumor depthNodal involvementDistant metastases

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10. Diagnostic Work-upExtremity: MRIRetroperitoneal/Intraperitoneal: CT Scan or MRIChest CT Scan for pulmonary metastasis Core needle biopsy preferred biopsy technique (incisional biopsy is an option)PLAN biopsy site well! Biopsy site and track must be including in the surgical resection.Plan incision along long axis of extremity.During biopsy limit the dissection so as not to contaminate tissue planes with tumor.

11. Preoperative biopsy for suspected sarcoma precautions/concerns:Biopsy non-diagnostic in 15% of patientsInsufficient specimenInterpretation – “spindle lesion”Delay in therapy – requests for many immunostaining*For lesions that are small, superficial, mobile, separate from skeletal or neurovascular structures - may be excised with wide gross margins even without preoperative biopsy/imaging of the primary*Tumors that are large, close to vital structures, fixed  preoperative biopsy

12. Indications for preoperative imaging and biopsy:Inability to determine extent of mass on PESuspected neurovascular involvementSuspicion for regional or distant metastasisNeeded operation will likely result in significant functional deficitsSuspicion that mass is unresectable or resectable with questionable surgical margins at presentation

13. Surgery for STSwide excision ± adjuvant RTMargin : at least 1 cm in all directions or include fascial barrier (1-2 mm)Radiotherapy – decreases recurrence by 20-25%, no improvement in OS>5 cm, high grade, positive marginsNo RT for <5 cm, low grade, superficial tumorsExtremity STS: limb-preserving surgery over amputationPrimary amputation: massive disease such that functional limb not achievable, need for resection of major nerves, compromised tissue perfusionLymphadenectomy only if clinically positiveSurvival advantage with metastasectomysingle organ metastases with limited tumor bulk, with control of primary

14. SARCOMAChemo-sensitiveEwing sarcomaRhabdomyosarcomaSynovial sarcomaMyxoid/round cell liposarcomaUterine leiomyosarcomaChemo-insensitiveWell-differentiated liposarcoma/atypical lipomatous tumorAlveolar part sarcomaClear cell sarcomaAbsence of effective systemic therapy for sarcoma in general

15. Retroperitoneal Sarcoma80% retroperitoneal tumors malignantCommonly liposarcoma or leiomyosarcomaDifferentials: lymphoma, germ cell tumorsPreop biopsy not mandatory, do if:if pre-op therapy neededMetastatic diseaseHigh suspicion of lymphoma, germ cell tumors, caricnomaContraindications to resection: extensive vascular involvement(aorta, vena cava, and or iliacs) – VC and iliac veins may be relativePrimary pattern of treatment failure is local

16. Gastrointestinal Stromal TumorInterstitial cells of CajalCD117/c-kit (80%) or PDGFRA (5-10%) <2 cm: may be observed if no high risk endoscopic features:Irregular border, cystic spaces, ulceration, echogenic foci, heterogeneityLN mets rareVirtually all GISTs have malignant potentialPrognosis depends location, size and mitotic rateGastric GISTS have better prognosis than small bowel/colorectal GISTSurgery: complete gross resection with histologically negative margins and intact pseudocapsule Imatinib – oral tyrosine kinase inhibitorAdjuvant therapy for 3 years (400 mg OD)