Atypical Manifestations of Primary Pulmonary Adenocarcinoma With Signet Ring Features: A Case Report.

Primary pulmonary malignancies are one of the most common malignancies worldwide. The most common non-small cell lung malignancy is adenocarcinoma, but there are many subtypes with different molecular and genetic expressions causing different manifestations. Uncommon manifestations include persistent back pain and tracheal bronchial tumors. More than 95% of reported tracheal bronchial tumors are benign and thus are rarely biopsied. There are no reported cases of secondary tracheal bronchial tumors due to pulmonary adenocarcinoma. Today, we are reporting the first case report of an uncommon manifestation of primary pulmonary adenocarcinoma.