[Incidence of non-metastatic liver lesions in tumor patients: consequences for chemotherapy and local ablative procedures]

Abstract

Introduction: Even in patients with a history of solid malignant tumors, especially of gastrointestinal origin, newly diagnosed solid liver lesions do not necessarily correspond to metastases of the respective primary tumor. A reliable diagnosis can only be made by definitive histological examination.

Material and methods: Data of all patients who underwent liver resection under the preoperative diagnosis of liver metastases between 1997 and 2011 and for whom liver specimens were examined histologically, were extracted from the prospectively maintained cancer registry.

Results: An unexpected histological result occurred in 47 out of 770 patients (6.1 %). Primary tumors in these patients included renal cell (n=12), colorectal (n=11), breast (n=8), gastric (n=4), pancreatic (n=3), skin (n=3) and other cancers (n=6). Liver lesions were diagnosed synchronously in 15 cases or metachronously after a median of 17 months following primary therapy in 32 patients. Histology revealed a benign tumor in 38 cases (81 %) as well as 6 cases of HCC, 2 cases of CCC and in 1 case metastasis of a previously unknown colorectal cancer in a patient with known esophageal carcinoma. Suspicion of metastatic disease was based on four different imaging modalities in two cases and on three different imaging modalities in nine cases. Either computed tomography (CT) or magnetic resonance imaging (MRI) was combined with ultrasound in another 23 patients and with positron emission tomography (PET) CT in 6 more cases. In two patients CT plus MRI and CT only, respectively, was performed. In the remaining three patients, suspicion of metastases occurred intraoperatively after macroscopic examination of the liver. Preoperative percutaneous biopsy was attempted in four patients with indeterminate results.

Conclusion: Even with modern diagnostics the risk of treating a benign or other form of malignant tumor with neoadjuvant or palliative chemotherapy persists. The same holds true for local ablative procedures. Prior to local ablation or definitive palliative chemotherapy histological confirmation of metastases should be attempted.