Symptomatic Rosai-Dorfman Disease Presenting as Isolated Bilateral Perinephric Infiltration.

This case explores a rare initial presentation of Rosai-Dorfman disease isolated to the peri-renal space. Also described as sinus histiocytosis with massive lymphadenopathy, Rosai-Dorfman disease is non-neoplastic and most often presents with massive cervical lymphadenopathy, but the disease can affect any organ system. Not often considered by those in the urology community or found in urology journals, this report reviews a clinical presentation of Rosai-Dorfman disease affecting bilateral kidneys and the fundamental histopathology needed for its diagnosis.

Melanoma cell-derived exosomes promote epithelial-mesenchymal transition in primary melanocytes through paracrine/autocrine signaling in the tumor microenvironment.

The tumor microenvironment is abundant with exosomes that are secreted by the cancer cells themselves. Exosomes are nanosized, organelle-like membranous structures that are increasingly being recognized as major contributors in the progression of malignant neoplasms. A critical element in melanoma progression is its propensity to metastasize, but little is known about how melanoma cell-derived exosomes modulate the microenvironment to optimize conditions for tumor progression and metastasis.