Benign / nonneoplastic lesions
Tunnel clusters

Topic Completed: 1 May 2007

Revised: 27 December 2018, last major update May 2007

Copyright: (c) 2007-2018, PathologyOutlines.com, Inc.

PubMed search: Tunnel clusters cervix

Branko Perunovic D.M.
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Cite this page: Perunovic B. Tunnel clusters. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cervixtunnelclusters.html. Accessed January 25th, 2020.
Definition / general
  • Incidental finding with no associated gross abnormality
  • Benign, does not recur
  • 80% have had 3+ prior pregnancies
Microscopic (histologic) description
  • Lobular proliferation of endocervical glands (clefts) with side channels growing out of them
  • Close to endocervical canal
  • May be dilated due to inspissated eosinophilic secretions
  • Low power appearance is lobular with one or more discrete foci of cystically dilated endocervical glands
  • May extend deep into cervical wall
  • Usually well circumscribed but may have pseudoinvasive appearance
  • Benign nuclear features
  • Minimal atypic
  • No stromal desmoplasia
  • Type A glands: smaller; noncystic tubules that resemble mucosal folds cut in various planes; may have florid glandular proliferation, and mild nuclear atypia but are still lobular and have minimal mitotic activity
  • Type B glands: cystic or dilated tubules arranged in lobular units; often multifocal, up to 2 mm in diameter individually; lined by bland cells with no mitoses, no / minimal nuclear atypia
Microscopic (histologic) images

Images hosted on PathOut server:

With dense secretion

Negative stains
  • Intracytoplasmic CEA, Ki67 (or low)
Differential diagnosis
Additional references
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