ascus

noun

as·​cus ˈa-skəs 

plural asci ˈa-ˌskī  -ˌskē 

ˈa-ˌsī

: the membranous oval or tubular spore case of an ascomycete

Word History

Etymology

New Latin, from Greek askos wineskin, bladder

First Known Use

1828, in the meaning defined above

Medical Definition

ascus

1 of 2 noun

as·​cus ˈas-kəs 

plural asci ˈas-ˌ(k)ī  -ˌkē 

: the membranous oval or tubular sporangium of an ascomycete

ASCUS

2 of 2 abbreviation

variants also AS-CUS

atypical squamous cells of undetermined significance

Note: ASCUS is a diagnosis used in cytology to describe the presence of abnormal squamous cells in a Pap smear test. Upon staining, these cells exhibit an atypical appearance (as enlarged nuclei or irregular shape) that cannot definitively be classified as benign or precancerous.

Many physicians believe that combining the Pap test with direct virus testing may prove particularly useful when a pap test comes back with its most common indeterminate result, called ASCUS—atypical squamous cells of undetermined significance.

—Jerome Groopman, The New Yorker

Currently, there is no consensus on what to do with ASCUS patients, only 5% to 10% of whom actually have precancerous cells.

—Rita Rubin, USA Today