Metastatic incidence of (PET)CT positive lung hilar and retroperitoneal lymph nodes in esophageal cancer patients.

BACKGROUND: Extra-regional lymph node metastases strongly determine treatment options in patients with esophageal cancer. Staging modalities such as (FDG-PET) CT scanning frequently show activity in retroperitoneal and lung hilar lymph nodes. This study evaluated the incidence of histologically confirmed metastases, treatment approach and recurrence patterns in patients with (FDG-PET) CT positivity in these regions. METHODS: All patients with (FDG-PET-) CT positive hilar and/or retroperitoneal lymph nodes at primary staging or restaging discussed at a multidisciplinary tumor board meeting for staging of esophageal cancer between January 2012-December 2017 were included. Biopsies and follow-up were evaluated to determine the presence of metastases and progression rates. RESULTS: From 2012 to 2017, 65 of 857 patients (7.6%) were selected with positive retroperitoneal and/or hilar lymph nodes. A total of 47/65 (72.3%) patients had positive retroperitoneal lymph nodes, which contained metastases in 19 (29.2%). When no biopsy was performed and curative treatment was given (n = 14), 9 patients had progression or locoregional and distant recurrence. Positive hilar lymph nodes were identified in 21 (32.3%) patients; 4 were biopsied and none contained metastases. In these patients no recurrence of disease was seen during follow-up. CONCLUSIONS: The majority of biopsied (PET)CT-positive retroperitoneal lymph nodes at staging contained metastases, while biopsied (PET)CT-positive hilar nodes did not. Histological evaluation of (PET)CT -positive retroperitoneal lymph nodes at staging imaging is recommended, while based on this small series, (PET)CT-positive hilar lymph nodes most likely represent reactive lymphadenopathy.

A rapid and simple method for visualizing milky spots in large fixed tissue samples of the human greater omentum.

Milky spots are unique lymphoid structures in the greater omentum that participate in both immune homeostasis of the peritoneal cavity and formation of omental metastases. We developed a rapid and simple staining method to enable macro- or stereomicroscopic identification of these miniscule structures in large samples of fixed human greater omentum. By immersing approximately 6 × 4 cm samples of omental tissue in hematoxylin, these samples could be evaluated quickly for the presence of milky spots. We used an alum hematoxylin variant containing 1 g hematoxylin, 50 g aluminium ammonium sulfate, 0.2 g sodium iodide, 1 g citric acid and 50 g chloral hydrate. This staining method enabled us to determine the number, location, dimensions and topographical relation of milky spots to other structures. Our method also facilitates isolation of milky spots for further investigation. Hematoxylin imparts a blue color to the milky spots, which remains in place during further processing for paraffin embedding. This enabled easy recognition of milky spots during transfer through various solutions and permitted selection of relevant paraffin slides prior to additional staining.

ypT0N+ status in oesophageal cancer patients: Location of residual metastatic lymph nodes with regard to the neoadjuvant radiation field.

INTRODUCTION: A subset of oesophageal cancer patients has residual nodal disease despite complete pathologic response of the primary tumour after neoadjuvant chemoradiation and resection. The aim of this study was to determine the exact location of metastatic nodes with regard to the neoadjuvant radiation field and to assess progression-free (PFS) and overall survival (OS) in this group of patients. MATERIALS AND METHODS: From January 2010 to January 2017, complete tumour responders (ypT0) after neoadjuvant chemoradiotherapy and oesophagectomy were identified from a prospective database and grouped according to residual nodal disease (ypT0N + or ypT0N0). Radiation fields were analysed for location of the metastatic nodes and PFS and OS were determined. RESULTS: In a total of 192 patients, 53 complete responders (ypT0) were identified. Of those, 11 patients (20.8%) were ypT0N+ with a total of 12 metastatic nodes: 8 (66.7%) located within the neoadjuvant radiation field and 4 (33.3%) located outside this field. Although not statistically significant, 1- and 2-year PFS were worse in ypT0N + patients (ypT0N+ 64.3% vs. ypT0N0 84.4%; ypT0N+ 48.2% vs. ypT0N0 80.7%, respectively; p = 0.051), just as 1- and 2-year OS rates, however, to a lesser extent (ypT0N+ 75.0% vs. ypT0N0 76.3%; ypT0N+ 75.0% vs. ypT0N0 72.9%, respectively; p = 0.956). CONCLUSION: Most ypT0N + lymph nodes are located within the neoadjuvant radiation field. Although a small heterogeneous population was included, this might be due to an inadequate response to neoadjuvant chemoradiotherapy leading to a trend towards worse PFS and OS in ypT0N + patients. Larger studies need to validate our findings.