Intraoperative sentinel lymph node mapping in patients with colon cancer.

BACKGROUND: The sentinel lymph node (SLN) mapping technique has been used in breast cancer and melanoma, and was recently described for colon cancer. METHODS: Thirty-five patients with colon cancer underwent intraoperative SLN mapping. One milliliter of 1% isosulfan blue was injected subserosally around the tumor. The first nodal area that was highlighted with blue was identified as the SLN. All lymph nodes underwent examination with hematoxylin and eosin (H&E) stain. SLNs underwent additional sectioning and were stained with CAM 5.2. RESULTS: Lymphatic mapping adequately identified the SLN in 25 patients (71%). In the 15 cases where the SLNs were negative for metastases, all other non-SLNs were also negative (0% false negative rate). The SLN was the only site of metastases in 6 (17%) of 35 patients. CAM 5.2 staining provided the only evidence of micrometastases in 4 (11%) of 35 patients. CONCLUSIONS: Intraoperative SLN mapping is a feasible technique with a reasonable SLN identification rate (71%). The absence of metastases in the SLNs accurately predicts the status of the non-SLNs. Tumors in 11% of patients were upstaged by the demonstration of micrometastatic involvement, and these patients may benefit from further adjuvant chemotherapy.

Collagenous fibroma (desmoplastic fibroblastoma): a unique presentation as a goiter in an 88-year-old man.

Collagenous fibroma (desmoplastic fibroblastoma) is a recently described entity in the medical literature. This entity has been reported in various locations, including the upper extremities, posterior neck, upper back, lower extremities, abdominal wall, and hip. We report an interesting case of an 88-year-old man who presented with an apparent goiter involving the right anterolateral neck. Histologic studies revealed a well-circumscribed, paucicellular lesion composed of stellate and spindle-shaped fibroblasts separated by bundles of collagen. No mitotic figures, necrosis, or calcification was observed. The stellate and spindle-shaped cells were positive for vimentin and focally positive for desmin, indicating myofibroblastic differentiation. Our case exemplifies the diagnostic difficulties that these tumors may pose from the clinical and radiologic standpoint when they clinically present as a goiter.

Esophageal collision tumor (Large cell neuroendocrine carcinoma and papillary carcinoma) arising in a Barrett esophagus.

We report herein a unique case of an esophageal collision tumor composed of a papillary adenocarcinoma and a large cell neuroendocrine carcinoma arising in a Barrett esophagus. Hematoxylin-eosin and silver staining patterns, immunohistochemistry, and electron microscopy of the large cell neuroendocrine component are discussed.