Table 2 CT imaging and pathology of adrenal lesion accompanied with calcification.

Adrenal cyst

29

Calcification is usually located in the periphery of the cyst with water-like uniform density inside with no enhancement on CT imaging. Microscopically, the fibrous capsule wall tissue is covered with the pseudostratified ciliated columnar epithelium. Most adrenal cysts are hemorrhagic, with hemosiderosis and calcification contained in the cyst wall

Adrenal pseudocyst

2

Calcification was located peripherally on CT imaging. Microscopically, the wall is made up of inflammatory granulation tissue or fibrous tissue with no coverage of epithelial cells on the cyst wall surface

Adrenal myelolipoma

10

Fat density can be seen on the CT image. Microscopically, fat lipocytes in myelolipoma are uniformly distributed, with scattered calcifications inside but the CT value of calcification is not high

Adrenal mature teratoma

2

Calcification lesions are mostly patchy or curved, with the CT value high as 500HU. Histologically, well differentiation tissues contain 3 germ cell layers (ectoderm, mesoderm and endoderm)

Adrenocortical adenoma

10

Calcification is scattered and can be seen in the periphery or inside. Microscopically, it is composed of clear and compact cells; the tumor cells are arranged in a cord-like or acinar manner, with mitosis rarely seen

Adrenal angiolymphangioma

6

Calcification located in the periphery and presented a patchy shape on the CT image. In some cases, partitioned calcification foci can be seen inside. Histologically, the cystic spaces were lined by a single layer of flattened or focally hobnailed cells without atypia resembling that of normal lymphatics

Adrenal schwannoma

5

Calcification mainly located in the periphery on the CT image, forming an “egg shell-like” shape encircling the tumor. Microscopically, the tumor cells are spindle-shaped with no clear boundaries between cells, and cells are arranged in a whirlpool or palisade manner

Adrenal pheochromocytoma

1

Calcification presented a ring-like shape on the CT image, with a CT value larger than 500HU. Microscopically, most tumor cells are polygonal with rich granular or vacuolar alkalophilic cytoplasm and clear nucleoli, and cells are arranged in a nest-like, trabecular or acinar shape, and strongly positive Chromogranin A in immunohistochemistry

Adrenal hematoma

3

Calcification is mainly distributed in the peripheral wall of the hematoma and partitioned inside in a multiple manner. Microscopically, hemorrhage is localized within the adrenal tissue, with normal adrenal tissue surrounding the calcification

Ganglioneuroma

2

Calcification in ganglioneuroma presents as nodules inside the tumor on the CT image. Microscopically, patchy or scattered maturely differentiated gangliocytes are seen in unmyelinated nerve fibers

Adrenal macronodular hyperplasia

1

Calcification presents as a single spot inside the lesion on CT image. Microscopically, the adrenal cortex was occupied by multiple nodular lesions composed mostly of clear cells. In the internodular regions, no evidence of cortical architecture was observed

Adrenal cortical carcinoma

2

Calcification is spotty on CT image, scattering inside the tumor with a relatively low CT value of calcification (< 100Hu). The maximum diameter is relatively large, and the rumor is lobulated with an unclear boundary. Microscopically, most cells are dark, with a patchy or focal density showing nuclear abnormalities, clear nucleoli and nuclear mitosis, invading blood vessels or penetrating the capsule with extensive hemorrhage and necrosis

Liposarcoma

1

Calcification presents as a sporadic and punctate distribution inside the tumor on the CT image, with an CT value of calcification less than 100 HU. Microscopically, adipoblasts and mature adipocytes in different differentiation stages show obvious heterogeneity

Gastric adenocarcinoma metastatic to the adrenal gland

1

Calcification presents a scattered spotty distribution on the CT image, with a CT value of calcification lower than 100 HU. Microscopically, there is little lipid, and typical gastric adenocarcinoma cells