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.