Case 5

A 60-year-old male with an 5.3 cm right adrenal gland mass.

What is the diagnosis by morphology?

A: Well differentiated neuroendocrine tumor

B: Clear cell sarcoma

C: Adrenal cortical carcinoma

D: Phaeochromocytoma

E: Metastatic carcinoma

Answer

The correct answer is D. “Zellballen” pattern is most commonly described, consisting of nests of tumor cells with fibrous septa. The tumor cells classically display basophilic to amphophilic granular cytoplasm. The tumor cells are positive of GATA3, tyrosine hydroxylase, dopamine beta-hydroxylase, and general neuroendocrine biomarkers. Keratin is negative, which is helpful to exclude neuroendocrine tumors. In most cases, mitoses are very rare or absent, and Ki67 index is usually around 10%. An elevated Ki-67 should raise the possibility of other malignancy. Helpful but not reliable features of SDHx-related tumors: Cytoplasmic eosinophilia and/or intracytoplasmic vacuoles and clearing, and tight well-formed rounded nests of neoplastic cells; As a result of clear cell change, especially when accompanied by other morphological findings (e.g. thick vascular tumor capsule; myxoid and hyalinized stroma; rich vascular network intermixed with tumor cells exhibiting variable clear and amphophilic cytoplasm; absence of cytoplasmic hyaline globules), VHL disease may be suspected.

Case credit: UCSD Pathology

Author: Wangpan Jackson Shi, MD