FNH in men – an important differential diagnoses in metastatic diseases

Purpose: Liver FNH (focal nodular hyperplasia) are much rarer in males than in females. In case of a malignant disease they can be misjudged as a liver metastasis, especially if not previously documented.

Material and methods: During routine abdominal ultrasound we detected hypoechoic liver lesions of 14 – 18 mm in three men: one 47 year old with a large renal cell carcinoma, one 56 year old with a bronchial neoplasm and one 71 year old patient who was diagnosed with 4 malignant melanomas in the abdominal region one year later. Colour Doppler ultrasound, CEUS and abdominal MRI were performed in all three patients.

Results: Colour Doppler Ultrasound and CEUS showed the typical characteristics of a FNH. Abdominal MRI confirmed the diagnoses in two cases, the third one was suspected to be a melanoma metastasis by the radiologist. A later performed surgical excision proved the lesion to be a FNH as well.

Conclusion: The occurrence of FNH in men is much lower than in women. In a large study population of the Berlin-Charite of 292 patients with FNH only 8% were male. The influence of estrogens in growth of these lesions seems highly probable. We found three men between 47 and 71 years during routine ultrasound, who had an accompanying malignant disease. A correlation of FNH with malignant diseases is not described in the literature. Knowing the liver lesion being a FNH may have critical impact on therapeutic decisions.