Unexpected endometrial metastasis of a primary lung adenocarcinoma

Following diagnosis of primary malignancies, subsequent workup includes evaluation for metastasis. Each malignancy, both location and histologic features, have statistically common and less common metastatic patterns. Metastatic lung adenocarcinoma typically involves lymph nodes, liver, brain, and bone. Very rarely can it involve the reproductive tract. Specifically, in females, multiple reported cases include ovarian metastasis. Even rarer, endometrial metastasis, such as this case report, has been reported. Even with usual staging utility of PET/CT, common things remain common; knowledge of common metastatic patterns can bias overall interpretation. This case is a reminder that despite our tendencies to focus on frequent patterns, even the rarest of metastatic patterns are still possible.