Degenerative Changes in Aging Human Pelvic Lymph Nodes-A Reason to Rethink Staging and Therapy of Regional Malignancies?

Abstract

Lymph node metastases are common in pelvic urological tumors, and the age-related remodeling process of the pelvic lymph nodes influences metastatic behavior. The aim of this work is to characterize age-related degenerative changes in the pelvic lymph nodes with respect to their occurrence and extent. A total of 5173 pelvic lymph nodes of 390 patients aged 44 to 79 years (median 68 years, IQR 62-71 years) were histologically examined for degenerative structural changes. Lymph node size, lipomatous atrophy, capsular fibrosis, framework fibrosis, and calcifications were recorded semi-quantitatively and evaluated by age group. Significantly more lymph nodes <10 mm were found in older patients (p = 0.001). The incidence of framework fibrosis, capsular fibrosis, and calcifications increased significantly with increasing patient age (p < 0.001). In lipomatous atrophy, an increase in mild to moderate lipomatous atrophy was observed with increasing age (p < 0.001). In this, the largest study to date on this topic, age-related degenerative changes in pelvic lymph nodes were proven. Due to the consecutive decrease in hte filtration function of pelvic lymph nodes with increasing age, staging and therapy of metastatic pelvic urologic carcinomas should be reconsidered.

Keywords: aging; bladder cancer; immunosenescence; pelvic lymph node; pelvic urologic carcinoma; prostate cancer; skip metastasis.

Figure 1

Upper row left: LN with capsular fibrosis (≤30%, H&E, 50×); middle: LN with low framework fibrosis and moderate lipomatous atrophy (31–60%, H&E, 25×); right: LN with subtotal lipomatous atrophy (≥61%, H&E, 25×). Lower row left: LN with low framework fibrosis, capsular fibrosis and subtotal lipomatous atrophy (≥61%, H&E, 50×); right: LN with moderate framework fibrosis and calcifications (H&E, 100×).

Figure 2

F-18-PSMA-1007 imaging demonstrating a paraaortic metastatic suspicious finding 1 year after local therapy of the primary tumor and increasing PSA-level. Top with combined coronal and sagital CT and PET images, bottom with coronal and sagital PET images.