<P> Exception: In melanoma and Merkel cell carcinoma, ITCs are considered positive nodes and are designated as N1 or higher . </P> <P> Note: There are cancer site--specific designators to identify ITCs in nodes . Example: N0 (i+) in breast and gynecologic cancers applies to nodes with ITCs only . </P> <Tr> <Td> Pathological techniques for ITCs or detection of micro-metastasis </Td> <Td> ITCs or lymph node micro-metastases may be identified in lymph nodes by hematoxylin and eosin staining or by specialized pathological techniques, such as IHC for cytokeratin proteins for carcinomas . <P> Specialized pathology techniques such as IHC and molecular techniques are not recommended for routine examination of lymph nodes . </P> <P> The concepts regarding this staging rule continue to evolve, and further study is warranted . </P> </Td> </Tr> <P> Specialized pathology techniques such as IHC and molecular techniques are not recommended for routine examination of lymph nodes . </P>

This type of stage is also termed a fourth wall stage