Detailed cadaveric analysis of perivesical lymph nodes in cystectomy specimens.

INTRODUCTION: Perivesical lymph nodes were added to the 8th edition of American Joint Committee on Cancer (AJCC) staging for bladder cancer. Currently, these nodes are inconsistently evaluated at the time of radical cystectomy. The objective of this study was to provide a detailed anatomic evaluation of perivesical lymph nodes. MATERIALS AND METHODS: A radical cystectomy was performed on six un-embalmed cadavers with wide resection of perivesical tissue and meticulous care to separate the pelvic sidewall lymph nodes (e.g. obturator, external iliac) from the bladder and perivesical en-bloc specimen. Perivesical tissue dissection in 2 mm slices was performed with a board-certified pathologist. Lymph node size and location were recorded. RESULTS: Gross tissue resembling lymph nodes were identified in the perivesical tissue in 50% (3/6) of the specimens, with a total of six grossly identified lymph nodes. The mean size was 7.5 mm (2-16 mm). On histologic analysis, 4 of 6 (66%) putative gross lymph nodes had confirmed lymphoid tissue. The mean distance of the lymph nodes from bladder wall was 9 mm (3-15 mm). Eight anatomic locations for perivesical nodes were developed: urachal, anterior bladder wall, posterior peritoneum, bladder neck, bilateral pedicle, bilateral lateral bladder wall. CONCLUSION: This cadaveric study with meticulous dissection of the perivesical space confirms that perivesical lymph nodes are a distinct entity and separate from other lymph nodes in the true pelvis. Perivesical lymph nodes are not present in all subjects and pathologic evaluation is more difficult owing to the surrounding fat. We herein propose perivesical regions for evaluation which can serve as a foundation for future studies and anatomic grossing techniques.

Severe chronic bowel obstruction associated with brown bowel syndrome.

A 61-year-old alcoholic male with history of cholecystectomy presented with a 20-year history of recurrent bowel obstruction and a 30 lb weight loss. After numerous attempts at conservative management, exploratory laparotomy was performed, which showed no mechanical cause. Despite no clear etiology, the obstruction persisted and intensified. A follow-up computed tomography scan revealed a small bowel obstruction with concurrent megacolon. A total abdominal colectomy was performed, with ileostomy. Grossly, there was intestinal dilation up to 15 cm with prominent brown discoloration of bowel wall. No strictures or other fixed obstruction were identified. Microscopic examination revealed prominent lipofuscin-like pigment deposition, involving the muscularis propria, muscularis mucosae, and vascular smooth muscle. Histochemical staining was positive for periodic acid-Schiff and negative for iron and calcium, consistent with lipofuscin. The gross and histologic findings fit with brown bowel syndrome. Brown bowel syndrome is a very rare condition characterized by lipofuscin deposits predominantly within the smooth muscle of the muscularis mucosae and/or muscularis propria that imparts a brown color to the bowel. It is generally thought to be a smooth muscle mitochondrial myopathy due to chronic vitamin E deficiency secondary to fat malabsorption syndromes, resulting in free radicals causing peroxidation of unsaturated membrane lipids with accumulation of lipofuscin. Brown bowel syndrome may be seen in patients with alcohol abuse, maldigestion, chronic bowel inflammation, and intestinal lymphangiectasia. Our patient's severe chronic intestinal pseudo-obstruction, low levels of certain fat-soluble vitamins (A, D, and E), significant weight loss and history of cholecystectomy with alcohol abuse correlates with brown bowel syndrome clinically.