Chromaffin cell carcinoma

by Specialist

Smoldering cell carcinoma: Smoldering cell carcinoma accounts for about 4%-10% of renal cell carcinoma. The average age of onset is 60 years, and the incidence rate is approximately equal for men and women. There are no specific clinical symptoms and signs compared with other renal cell carcinoma subtypes. The imaging features mostly show large tumors with uniform density or signal, without hemorrhage, necrosis, or calcification.

  • Major examination: The tumor is unencapsulated but well-defined, with a uniform brownish texture on the cut surface, and necrosis is seen, but hemorrhagic foci are rare.

  • Histopathology: The tumor is solid and lamellar, but may also be small nests, microcysts, beams, and occasional papillae. Unlike clear cell carcinoma, the blood vessels in the tumor are thick-walled rather than thin-walled; the tumor cells are large and polygonal with a clear, slightly reticulated cytoplasm and a very clear cell membrane (suspicious cells). The histologic features include: small cells with a slender eosinophilic granular cytoplasm; eosinophilic cells located in the center of the cell nest and pale cytoplasmic cells located at the periphery of the cell nest; irregularly crinkled nuclei with clumped chromatin, binucleated cells and a perinuclear halo; and round cells are also seen.

    • Commonly used immunohistochemical antibodies: positive for CK, CK7, EMA, leptins, and parvalbumin, weakly positive for renal cell carcinoma antigen, and negative for vimentin and CD10. Immunohistochemical staining is not necessary for diagnosis and is used only in difficult cases.

    • Special staining: Hale colloidal iron shows diffuse positivity of tumor cells.