4.9 Surgical Oncology and Malignancies

Malignancies and the Surgical First Assistant

The CSFA content outline requires applying advanced knowledge of pathophysiology and histology to the handling and manipulation of tissue for malignancies, including carcinomas, sarcomas, neurological malignancies, lymphatic malignancies, and metastatic disease. Cancer surgery is unique in that the quality of the tissue handling directly affects the oncologic outcome: tumor spillage, margin violation, or inadequate resection all increase local recurrence and decrease survival.

General Principles of Surgical Oncology

1. En bloc resection with negative margins (R0 resection). The tumor is never entered.
2. No-touch technique. Tumor manipulation is minimized to reduce the risk of tumor cell shedding into the bloodstream or peritoneal cavity.
3. Specimen orientation. The CSFA must help the surgeon mark the specimen (usually with a long suture for the superior margin, short for the inferior, etc.) so the pathologist can orient it for margin analysis.
4. Separate instrument setup for resection and closure. Instruments that contact the tumor are removed from the field before closure to prevent tumor implantation in the wound.
5. Frozen section availability. The CSFA must ensure the specimen is delivered to pathology promptly for margin assessment.

Carcinomas (Epithelial Origin)

Carcinomas are the most common malignancies the CSFA will encounter. Common surgical presentations:

Colorectal Adenocarcinoma. Resection follows the principles of complete mesocolic excision (CME) or total mesorectal excision (TME) for rectal cancer. The CSFA must help the surgeon dissect along the embryologic fascial planes (the mesocolic fascia or the holy plane of Heald) without breaching the mesorectal fascia. Violation of the mesorectum increases local recurrence from 8% to over 20% in rectal cancer.

Breast Carcinoma. Lumpectomy (breast-conserving surgery) requires a 1-2 mm negative margin in most guidelines. The CSFA must orient the specimen with sutures: short superior, long lateral, double-long inferior, double-short medial (institutional preferences vary). The specimen must be marked for the pathologist before it leaves the field.

Gastric Adenocarcinoma. D2 lymphadenectomy (clearance of stations 1-12) is the standard for curative resection. The CSFA must help identify and preserve the splenic artery and the pancreas tail while clearing the lymph nodes along the hepatic and left gastric arteries.

Pancreatic Adenocarcinoma. Pancreaticoduodenectomy (Whipple) requires en bloc removal of the pancreatic head, duodenum, gallbladder, distal bile duct, and regional nodes. The CSFA must help identify the superior mesenteric artery (SMA), the portal vein, and the inferior vena cava. The uncinate process is divided last and is the most common site of positive margin.

Sarcomas (Mesenchymal Origin)

Sarcomas (e.g., liposarcoma, leiomyosarcoma, osteosarcoma) have a pseudocapsule of compressed tumor cells that is NOT a true surgical margin. Resection must include a 2 cm cuff of normal tissue around the pseudocapsule. The CSFA must:

• Avoid any dissection along the pseudocapsule itself.
• Help mark the deep and superficial margins separately.
• Anticipate that en bloc resection may include adjacent structures (e.g., a femoral sarcoma may require segmental resection of the femoral artery with a vascular graft).

Retroperitoneal Sarcoma. A common sarcoma presentation. The CSFA must help mobilize the colon, kidney, and ureter off the tumor surface. The ureter should be encircled with a vessel loop. The aorta, IVC, and iliac vessels are often adjacent and must be controlled proximally and distally before tumor mobilization.

Neurological Malignancies

Glioblastoma Multiforme (GBM). The most common primary brain tumor in adults. Resection is guided by neuronavigation, intraoperative ultrasound, and sometimes fluorescence (5-ALA). The CSFA must support the use of the Cavitron Ultrasonic Surgical Aspirator (CUSA) for tumor debulking. The surrounding brain is edematous and eloquent cortex must be protected with cottonoid patties and gentle retraction.

Meningioma. Usually benign but highly vascular. Preoperative embolization may reduce bleeding. The CSFA must anticipate the need for a bipolar cautery for the tumor bed and the dural tail (the dural attachment, which is resected with the tumor).

Acoustic Neuroma (Vestibular Schwannoma). Arises from the vestibular branch of CN VIII. The facial nerve (CN VII) is displaced and stretched over the tumor and must be monitored with intraoperative electromyography. The CSFA must avoid any traction on the facial nerve and help the surgeon identify it before tumor removal.

Lymphatic Malignancies

Lymphoma. Surgical involvement is primarily for diagnostic biopsy or staging. If an enlarged lymph node is biopsied, the CSFA must handle the specimen gently and intact because crushing artifact makes pathologic diagnosis impossible. The node should be placed immediately in saline (for flow cytometry) or formalin (for histology), per the pathologist's preference. The CSFA should ask the surgeon for the proper container before the specimen is removed.

Splenectomy for Lymphoma. The spleen is mobilized by dividing the splenorenal, splenophrenic, and splenocolic ligaments. The short gastric vessels are individually ligated. The splenic artery and vein are ligated separately (artery first to reduce spleen size and minimize thrombocytopenia-related bleeding in hypersplenic patients).

Metastatic Disease

Liver Metastases. Colorectal liver metastases are the most common indication for liver resection. Wedge resection or formal hepatectomy requires the CSFA to help the surgeon define the Couinaud segments using intraoperative ultrasound. The hepatic veins, portal triads, and inferior vena cava must be controlled. The Pringle maneuver (clamping the hepatoduodenal ligament) is used to control inflow bleeding during parenchymal transection.

Lung Metastases. Wedge resection via VATS is the most common approach. The CSFA must help position the stapler across the lung parenchyma and confirm the lesion is included in the specimen.

Bone Metastases. Common from breast, prostate, lung, thyroid, and kidney primaries. Pathologic fractures may require intramedullary nailing with cement augmentation. The CSFA must prepare polymethyl methacrylate (PMMA) bone cement and be ready for a rapidly exothermic curing process.

Handling of the Cancer Specimen

Surgical Trap: The most common error in sarcoma surgery is to dissect along the apparent tumor capsule (the pseudocapsule), which is composed of compressed tumor cells. This always produces a positive margin and carries a local recurrence rate of 30-50%. The CSFA must help the surgeon stay 2 cm outside the pseudocapsule in normal tissue, even when the dissection crosses normal anatomic boundaries.