A retrospective study of SDHB and SDHD NIH patients' cohort, which included 41 patients with SDHB mutation-related PHEO/sPGL and 18 patients with either SDHD or SDHB mutation-related head and neck PGL (HNPGL) with both CgA and NMN measured at the time of diagnosis at NIH.
However, the immunostaining of CgA in the tumor cells showed peculiar dot-like staining located corresponding to Golgi complex in the perinuclear area, rather than the diffuse cytoplasmic staining usually observed in epinephrine- or norepinephrine-producing functional pheochromocytomas and paragangliomas.
Both the combination of plasma free metanephrine, normetanephrine and chromogranin A as determined by radioimmunoassays, which are simple without the necessity of special laboratory material, are effective markers of pheochromocytoma or paraganglioma.
Chromogranin A identified one of three PET/CT-visualized SDHB-related paragangliomas with normal plasma metanephrines at the expense of nine false-positive results.
Immunohistochemical expression patterns of S100, synaptophysin, chromogranin A and neuron specific enolase in predicting malignant behaviour in paragangliomas.