Adrenal gland & paraganglia

Other nonneoplastic

Adrenal rests

Last author update: 12 July 2022
Last staff update: 2 December 2022

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PubMed Search: Ectopic adrenal tissue

Yuto Yamazaki, M.D., Ph.D.
Hironobu Sasano, M.D., Ph.D.
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Cite this page: Yamazaki Y, Sasano H. Adrenal rests. website. Accessed February 23rd, 2024.
Definition / general
  • Nests or foci of adrenal tissue, detected in aberrant locations distant from the eutopic adrenal glands
Essential features
  • Ectopic adrenal tissue, also termed heterotopic adrenal tissue or adrenal rests, represents nests or foci of adrenal tissue detected in various locations distant from the eutopic adrenal glands
  • Adrenal rests are frequently detected in retroperitoneal, pelvic or groin areas, mainly composed of adrenocortical component
  • Steroidogenic factor 1 (SF1) is a useful immunohistochemical marker to identify adrenal rests
  • Heterotopic adrenal tissue, adrenal rest, renal adrenal fusion
  • Detected in both pediatric and adult subjects
  • Identified in retroperitoneal, pelvic or groin areas
  • Prevalence of involvement by location (Endocr Pathol 2021;32:375):
    • Paraovarian / ovarian / parasalpingeal / infundibulopelvic ligament, broad ligament (≈50%)
    • Spermatic cord / paratesticular (≈30%)
    • Inguinal hernia sac / inguinal fat (≈15%)
    • Peritoneal / appendiceal mesentery and others (intrahepatic / intrarenal, etc.) (≈5%)
  • Cortex originates from the intermediate mesoderm and medullary part from the neural crest
  • During the sixth to seventh week of gestation, the primordial aggregation of cortical cells is derived from the mesenteric root, medial to the developing gonads and anterior to the mesonephros
  • Compartment of chromaffin cells penetrates into the unencapsulated primordial adrenal cortex
  • Reference: Endocrinol Metab Clin North Am 2015;44:243
  • Common sites considered to be due to the abnormality of fusion or persistent remnants of adrenal ridge
  • Rare sites could be explained by abnormal migration of adrenal tissue during gestation or differentiation of adrenal progenitor stem cells (Mol Endocrinol 2009;23:1657)
Clinical features
  • Because the lesion is hormonally silent, diagnosis can be made only by histopathological examination, usually as an incidental finding
  • In rare cases, functional adrenocortical tumor (adenoma or carcinoma, even oncocytoma) could also arise from the adrenal nests
  • Reference: Endocr Pathol 2021;32:375
  • No characteristic findings
Radiology description
  • Generally undetectable by radiological examination
  • Rarely, the mass can be detected in cases of adrenocortical tumors arising from the ectopic adrenal tissues
  • Reference: Endocr Pathol 2021;32:375, Hernia 2016;20:879
Case reports
  • No treatment is required unless a neoplasm has developed in the ectopic tissue
Gross description
  • Golden yellow upon gross examination
  • May be grossly mistaken for an additional nodule of renal cell carcinoma in a nephrectomy or a lymph node in a lymph node dissection
Gross images

Contributed by Debra L. Zynger, M.D.
Partial nephrectomy

Partial nephrectomy

Microscopic (histologic) description
  • Composed of adrenal cortex, which is made of large polygonal cells, distinct cell membranes, vesicular eosinophilic to clear cytoplasm and bland nuclei
  • Medulla component is rarely present; more likely to be identified near the celiac plexus
  • Reference: Endocr Pathol 2021;32:375
Microscopic (histologic) images

Contributed by Yuto Yamazaki, M.D., Ph.D., Hironobu Sasano, M.D., Ph.D., Debra L. Zynger, M.D. and Sean R. Williamson, M.D.
Adrenal rest Nests of cortical cells SF1

Spermatic cord adrenal rest and SF1

Radical orchiectomies / spermatic cords with adrenal rests Radical orchiectomies / spermatic cords with adrenal rests Radical orchiectomies / spermatic cords with adrenal rests

Spermatic cord adrenal rests

Radical orchiectomies / spermatic cords with adrenal rests Radical orchiectomies / spermatic cords with adrenal rests

Paratesticular adrenal cortical rest

Intrarenal adrenals Intrarenal adrenals Intrarenal adrenals Intrarenal adrenals Intrarenal adrenals Intrarenal adrenals

Intrarenal adrenals

Positive stains
Negative stains
Sample pathology report
  • Left kidney, mass, robotic partial nephrectomy:
    • Renal cell carcinoma, clear cell type (see synoptic report)
    • Renal adrenal fusion
Differential diagnosis
Board review style question #1

Ectopic adrenal tissue is shown in the image above, identified in the renal hilum area in a 40 year old man as an incidental finding in a nephrectomy specimen. Which is the most useful diagnostic immunohistochemical marker to confirm the diagnosis?

  1. CD20
  2. CDX2
  3. SF1
  4. Vimentin
Board review style answer #1
C. SF1. Adrenal rests are generally composed of both clear adrenocortical cells and compact ones. However, the zonation is frequently blurred and only composed of either clear or compact cells. Nests of adrenal cortical cells are, in general, immunohistochemically positive for SF1, MelanA and inhibin A at both eutopic and ectopic sites.

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