Lung to Lung Cannon Ball Metastases: A Case Series on Primary Lung Malignancy

Cannon ball metastases refer to large, well circumscribed, round pulmonary nodules like cannon balls that are scattered over both lungs, being a classical presentation of haematogenous tumour spread.Cannon ball pulmonary metastases are typically seen in the patients with choriocarcinoma or renal cell carcinoma. Rarely, pulmonary metastases with the same appearance may be secondary from prostate cancer, synovial sarcoma, endometrial carcinoma or haepatocellular carcinoma.The present case series is about six patients diagnosed with cannon ball metastases which occurred from primary lung carcinoma. Out of these six cases, three were of small cell carcinoma, two of squamous cell carcinoma and one of adenocarcinoma.The histopathology of all the cases was established by biopsy from the tumour site and appropriate treatment was started in the form of chemotherapy and radiotherapy as needed. Clinicians must investigate thoroughly for primary origin of cannon ball metastasis, though rare but lung cancer can present as this kind of metastasis.