Which combination represents the panel for Metastatic Carcinoma?

Which combination represents the panel for Metastatic Carcinoma?

• A. CK7, CK20, TTF-1
• B. CK7, CK20
• C. CK20, TTF-1
• D. CK7, CK20, TTF-1

Answer: (D)

Determining the origin of a metastatic carcinoma often relies on a panel of markers that can distinguish between typical primary sites. CK7 and CK20 patterns help categorize carcinomas into broad groups: many lung, breast, ovarian, and some pancreatic or gynecologic cancers are CK7 positive, while colorectal cancers are often CK20 positive. TTF-1 adds a specific signal for tumors of the lung and thyroid, helping to pinpoint a lung or thyroid origin when present. Using all three markers together provides the most information from a single test. The CK7/CK20 profile gives you a broad framework for possible primaries, and TTF-1 positivity specifically points toward lung (or thyroid) origin, which is crucial when the primary site is unknown. If any one marker were missing, you’d lose part of that discriminating power: you might miss colorectal-type metastasis without CK20, misinterpret a lung-origin lesion without TTF-1, or lack helpful context without CK7. Therefore, including CK7, CK20, and TTF-1 offers the most informative initial panel for metastatic carcinomas.

Determining the origin of a metastatic carcinoma often relies on a panel of markers that can distinguish between typical primary sites. CK7 and CK20 patterns help categorize carcinomas into broad groups: many lung, breast, ovarian, and some pancreatic or gynecologic cancers are CK7 positive, while colorectal cancers are often CK20 positive. TTF-1 adds a specific signal for tumors of the lung and thyroid, helping to pinpoint a lung or thyroid origin when present.

Using all three markers together provides the most information from a single test. The CK7/CK20 profile gives you a broad framework for possible primaries, and TTF-1 positivity specifically points toward lung (or thyroid) origin, which is crucial when the primary site is unknown. If any one marker were missing, you’d lose part of that discriminating power: you might miss colorectal-type metastasis without CK20, misinterpret a lung-origin lesion without TTF-1, or lack helpful context without CK7.

Therefore, including CK7, CK20, and TTF-1 offers the most informative initial panel for metastatic carcinomas.