Zellballen

Synonyms

Cell clusters

Introduction

Zellballen is German for “ball of cells.” It is a histological description of a particular growth pattern and almost exclusively used (and virtually pathognomonic) for paraganglioma and pheochromocytoma. The German Anatomist Alfred Kohn introduced the term in 1903 (Böck 1982).

Function

Chromaffin cells may produce adrenalin, noradrenalin, or dopamin. Rarely also other active molecules may be produced and secreted.

Macroscopy

Zellballen per se are not visible by the naked eye (since it is a histological term).

Microscopy

A zellballen is a small nest of chromaffin cells or chief cells with pale eosinophilic staining. Zellballen are separated into groups by segmenting bands of fibrovascular stroma, and are surrounded by supporting sustentacular cells. A zellballen pattern is diagnostic for paraganglioma or pheochromocytoma (La Perle and Dintzis 2018).

Immunophenotype

The chromaffin cells are typically positive for neuroendocrine markers (synaptophysin...