Cannon ball pulmonary metastases

Ulcer-forming colon cancer can develop cavity-forming metastatic lung tumors

A 67-year-old man with abdominal pain and vomiting was referred to our hospital for the treatment of ileus. Enhanced computed tomography (CT) showed marked dilatation of the ileum and a presumed cecal tumor. After the intestinal decompression using nasogastric tube, a colonoscopy showed a type 3 tumor in the cecum. Endoscopic biopsy pathologically showed atypical cells growing in a cribriform fashion, leading to the diagnosis of cecal cancer. Staging CT showed multiple lung nodules either in a solid or a cavity-forming fashion and a presumed peritoneal disseminating lesion. Smaller lung nodules tended to show a solid pattern and larger ones a cavity-forming pattern. On diagnostic laparoscopic operation, a frozen section of the resected peritoneal lesion proved peritoneal dissemination. The patient, therefore, underwent palliative colectomy with functional anastomosis followed by thoracoscopic resection of one cavity-forming lung nodule for the accurate evaluation of the disease spread. Pathologic study showed marked tumor tip deciduation of cecal cancer and interminglement of necrotic tissue and exfoliated cancer cell clusters in the cavity of the metastatic lung tumor. Oncologists should note that ulcer-forming colon cancer can develop metastatic lung tumors in a cavity-forming fashion. Co-presence of small solid nodules and large cavity-forming ones suggests metastatic lung tumors from ulcer-forming colon cancer.

Cannonball-Like Lung Nodules in a Patient With a Colorectal Tumor

CASE PRESENTATION

A 72-year-old man underwent endoscopic resection of a 10-mm polypoid sessile lesion of the rectum. Histologic examination found a well-differentiated, low-grade (G1), neuroendocrine tumor. A thoracoabdominal CT scan was performed for staging purposes. The chest CT scan revealed a so-called cannonball-like distribution of multiple rounded nodules, with well-defined margins, ranging from 0.5 to 5 cm, scattered in both lungs (Figs 1A, 1B). The abdominal CT scan showed no abnormalities. A recent colonoscopy showed no evidence of malignancy. No prior chest imaging was available and the patient had never complained of respiratory symptoms. The patient was a former smoker, with a smoking history of 20 pack-years. He had a history of hypertension, mild stenosis of both carotid arteries, and benign prostatic hypertrophy. He reported the presence of long-standing multiple cutaneous hemangiomas on the trunk and face and a larger hemangiomatous lesion on his left lower limb, which was previously investigated by color Doppler ultrasound imaging. All these lesions were reported as unaltered and unchanged since early infancy.