Test Method

IHC

CPT Code

88342 x 1
88341 x 1

Stains / Test Description

Napsin is a pepsin-like aspartic proteinase, in the A1 clan of the AA clade of proteinases. There are two closely related napsins, napsin A and napsin B. Napsin A is expressed as a single chain protein with the molecular weight of approximately 38 kDa. Immunohistochemical studies revealed high expression levels of napsin A in human lung and kidney but low expression in spleen. Napsin A is expressed in type II pneumocytes and in adenocarcinomas of lung. The high specificity expression of napsin A in adenocarcinomas of lung is useful to distinguish primary lung adenocarcinomas from adenocarcinomas of other organs.

Specimen Requirements

(1) H&E slide with formalin-fixed, paraffin-embedded (FFPE) tissue, fixed with 10% NBF.
or
One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4 microns) for each test/antibody ordered

Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.

Storage & Transport

Ship specimen same day (whenever possible) with refrigerated (not frozen) cold pack

Turnaround time

1-3 days depending on level of service

Level of Service

Global (with interpretation)
Slide Only (glass slides only)
Web-Enabled (glass and digital images through eCSI portal)