Primary epithelioid angiosarcoma of the adrenal gland: aggressive histological features and clinical behavior

Abstract

Primary adrenal epithelioid angiosarcoma (PAEA) is an exceedingly rare and high-grade malignant neoplasm with an epithelioid appearance morphologically. To the best of our knowledge, only 35 cases of PAEA have previously been reported in English literature. Here, we present our 7-year experience (2010-2017) with adrenal lesions at our Clinical Pathological Diagnosis Center. Of more than 1,800 adrenal gland specimens, a total of 2 adrenal epithelioid angiosarcoma cases were identified. We reviewed the literature for 13 similar cases. All of the patients appeared to have morphological features of epithelioid cells including vascular endothelium immunophenotype, hemorrhage/necrosis, and anastomosing vascular channels. They underwent adrenalectomy without chemotherapy or radiotherapy. One was still well at 3-year follow up but the other had died at 1-month follow up. One of our cases was first described with accompanying reactive adrenal cortex hyperplasia in a local area. Moreover, the mechanisms of epithelioid angiosarcoma are still uncertain and require further study. Clinical prognosis is poor, therefore early accurate diagnosis and complete resection of this tumor may be very helpful for patients.

Keywords: Primary adrenal epithelioid angiosarcoma; adrenal cortex hyperplasia; immunohistochemistry; morphology; poor prognosis.

Figure 1

CT scan of the mass indicated by an arrow; regions as follows: A. The left adrenal gland of case 1; B. The left adrenal gland of case 2 and no clear demarcation between the lesion and adjacent tissues.

Figure 2

Microscopic features of adrenal epithelioid angiosarcoma of case 1 (A, B) and case 2 (C-H). Irregular epithelioid cells invaded the adrenal gland and lined up along the vascular lumen (A, B) or appeared a sheet-like pattern (C, D). Cells were characterized by abundant eosinophilic cytoplasm, enlarged nuclei, prominent nucleoli, and increased mitotic activity (E, F). Tumor with reactive adrenal cortex hyperplasia (G) exhibited that irregular epithelioid cells were negative for inhibin α but cells of reactive adrenal cortex hyperplasia were positive for inhibin α (H).

Figure 3

Immunohistochemical staining appearance of tumors in our two cases. The irregular epithlioid cells strongly and diffusely expressed vascular differentiation markers CD31, CD34, ERG, and Fli-1 (A-D). The Ki67 proliferative index is about 20% (E). A few scattered cells were positive for CK (pan) (F). The cells showed negative for Melan-A and HMB45 (G, H) and showed positive for vimentin (I).