Prominent apical cytoplasmic bleb formation in metanephric adenoma: report of a case

Abstract

In a case of metanephric adenoma of the kidney, many apical cytoplasmic blebs were found on the luminal surface of tumor cells. The tumor, measuring 15 mm in diameter, was found incidentally in the right kidney of a 40-year-old woman. It consisted of a dense proliferation of cuboidal cells forming small tubules of round or irregular shape. The apical portion of the cytoplasm of tumor cells exhibited club-shaped expansion or dome-like protrusion which was largely occupied by numerous free ribosomes. The neck portion of the protruded apical cytoplasm was constricted, and the apical cytoplasm appeared to have been "pinched-off" and shed into the lumen. The prominent formation of apical cytoplasmic blebs has, to our knowledge, not been documented in renal tumors except in angiomyoadenomatous tumors. Its pathological significance is unknown, but it most likely represents a response of tumor cells to some hypoxic or toxic cellular injuries.

Regulation of apical blebbing in the porcine epididymis

“…Apical blebbing is a ubiquitous process used by cells during secretion, mitosis, migration and apoptosis, and characterizes some disease states (Charras et al. ; Cocucci & Meldolesi, ; Shintaku & Maeno, ; Yamamoto et al. ).…”

“…Apical blebbing is a ubiquitous process used by cells during secretion, mitosis, migration and apoptosis, and characterizes some disease states (Charras et al 2008;Cocucci & Meldolesi, 2015;Shintaku & Maeno, 2016;Yamamoto et al 2016). Molecular mechanisms involved in the release of these vesicles as well as conditions influencing the occurrence of blebbing (Tokuda et al 2016;Zhang et al 2016) have been studied in vitro.…”