The classification of a stage-1 tumor is dependent not only on primary tumor resection, but also on microscopic evaluation of regional nodes. It is imperative that the surgeon seek and biopsy lymph nodes in the main draining lymphatic echelons at the time of primary tumor removal. For adrenal primaries the ipsi-lateral peri-caval nodes on the right, or peri-aortic nodes on the left, should be sampled. The surgeon should also evaluate interaortocaval lymph nodes located in the space between the abdominal aorta and inferior vena cava, as well as those located either supra-renally or infra-renally, or both. In assessing these nodes, the surgeon should separate the aorta and vena cava and visualize the spine posteriorly. Finally, an assessment of contralateral lymph nodes and those at the base of the mesentery should be performed. For a right-sided adrenal primary, examination and biopsy of the contralateral peri-aortic nodes should be done. Conversely, contralateral peri-caval lymph nodes should be sampled for left-sided primaries. If these nodes cannot be identified, the surgeon must comment on this in the operative note documenting that they were actively sought.
For thoracic primaries, peri-aortic nodes on the left and peri-azygous nodes on the right should be assessed, and any abnormal nodes running along the intercostals vessels should be excised. It is helpful to biopsy normal-appearing nodes in these regions when feasible. In the case of pelvic primaries the lymph nodes running along the iliac vessels should
Resection of a cervical neuroblastoma. A transverse neck incision followed by dissection of the carotid sheath contents was done. Division of the tumor over blood vessels is a characteristic of neuroblastoma surgery be sampled as well as those in the lower peri-aortic and peri-caval regions. The level II-IV jugulo-digas-tric lymph nodes are sampled with cervical primar-ies(Figs. 11.4.1-11.4.3).
The criteria for stage 2 focus on the extent of primary tumor resection and on the microscopic assessment of ipsilateral lymph nodes. The contralateral region is explored and identifiable lymph nodes are sampled. If thorough review of pre-operative imaging and intraoperative exploration fails to identify contralateral lymph nodes, then this should be documented in the operative note.
Stage-3 disease crosses the midline and is usually associated with encasement of the great vessels. In the abdomen, the aorta and/or vena cava, as well as the celiac axis, superior mesenteric artery, and renal arteries, may be involved. In the mediastinum encasement of the thoracic aorta or azygous vein can occur. Vascular encasement prevents or complicates gross total resection; however, on occasion, tumors that appear to be stage 3 by imaging studies obtained pre-operatively can at times be completely resected (gross total resection), thus down-staging the patient to stage 1,thereby improving prognosis and eliminating the need for further therapy. The ability for tumor surgery to change risk classification, should not be underestimated. Haase et al. (1989) reported an improved survival in Evans stage-III
The approach for posterior mediastinal tumors. A muscle-sparing technique can be used for small lesions.Infiltration through spinal foramina may require foraminotomy.
patients who underwent gross total resection. A similar finding was noted by Matthay et al. (1998).
In the past, the role of surgery in stage-4 disease was limited. Presently, besides playing a key role in establishing the diagnosis, the surgical oncologist can ensure the procurement of adequate tissue for assess ing relevant biologic parameters, even in cases where the diagnosis can be made solely based on urinary catecholamines plus bone marrow studies. It is recommended that at least 1 cm3 of viable tumor tissue be obtained at initial biopsy, although this volume requirement is likely to be substantially reduced with future refinements in various molecular techniques. Foremost among biological parameters is determination of the MYCN proto-oncogene copy number. Tu-
a A thoracoabdominal approach.
Figure 11.4.3 b b Transection of a tumor mass that circumferentially encases the renal vessels.This maneuver is often necessary in neuroblastoma resection.
mor tissue is also needed for histologic classification and tumor cell ploidy analysis (Joshi et al. 1992; Joshi et al. 1996; Shimada et al. 1984; Bowman et al. 1997). Unfortunately, outcome for patients with high-risk stage-4 neuroblastoma remains poor, with overall long-term survival rates <30% (Olgun et al. 2003; Frappaz et al. 2002). Progress in this disease will require basic investigations requiring fresh or fresh frozen tissues. The surgeon should make every effort to obtain extra tissue that can be used for these purposes. The role of gross total resection in stage-4 neu-roblastoma remains controversial and is dealt with later in the section on high-risk tumors.
Neuroblastoma patients are presently classified as low, intermediate, or high risk by clinical and biological criteria (see Chap. 7). The neuroblastoma committee of the COG recommends complete tumor removal in each risk group when feasible. In the final analysis, a decision to attempt complete tumor resection must be dependent on the consulting surgeon in collaboration with the attending pediatric oncologists and after careful review of the clinical situation as well as imaging studies. It is strongly recommended that these patients be reviewed at a tumor board or treatment planning conference with oncologists, diagnostic radiologists, and surgeons in attendance. Some of these resections may be technically difficult and the surgeon should not hesitate to obtain consultation from experienced colleagues if he or she is unsure as to the appropriate course. Web-based resources including clinical guidelines for neuroblas-toma surgery based on the risk-dependent COG protocol are available through both the COG and American Pediatric Surgical Association (APSA) websites. In addition, the surgical principal investigator assigned to a specific COG neuroblastoma therapeutic protocols can be contacted through the COG website. The timing of definitive resection is based on risk status.
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