Epithelial microchimerism: consistent finding in human liver transplants.

BACKGROUND: Eleven liver biopsies from six male patients who received a liver transplant (LT) from female donors were examined in order to determine whether male host-derived hepatic cells were present in female grafts that exhibited minimal or important inflammatory damage. METHODS: Immunohistochemistry for epithelial cell type differentiation (anticytokeratin monoclonal antibody) and fluorescence in situ hybridization for XY chromosomes identification were performed on each slide. RESULTS: Host-derived hepatic cells were found in all except one transplant, with a frequency ranging from 2.3 to 25 per thousand of the total hepatocytes in the biopsy specimen. They were usually found as isolated cells scattered throughout the hepatic lobule; in one patient they were grouped into little clusters. Host-derived hepatic cells persisted throughout the histological follow up (up to 535 days after LT). Polyploidy for XY chromosome was observed. CONCLUSION: Hepatocytes derived from extra-hepatic stem cells are frequently found in small numbers in human liver grafts and persist over time.

Myxoid adrenocortical adenoma with a pseudoglandular pattern.

Myxoid changes rarely occur in adrenocortical adenomas and carcinomas. Only eight benign tumours with such features have been described thus far, five of which also had a prominent pseudoglandular component. We report an additional pseudoglandular myxoid adenoma of the adrenal gland detected in a 58-year-old male patient who developed mild hypertension. At surgery, a 4-cm mass was resected and found to contain cords and tubules of polygonal cells in a myxoid background. Limited areas of classical adrenocortical adenoma were detected in less than 20% of the tumour area. Lack of atypias and absence of mucin markers, together with an immunophenotype consistent with adrenal tumours (focal cytokeratin, vimentin, synaptophysin and alpha-inhibin immunoreactivities), led to a diagnosis of primary adrenocortical adenoma with an extensive pseudoglandular myxoid pattern. However, the differential diagnosis from metastatic well-differentiated adenocarcinomas, chordomas and retroperitoneal myxoid mesenchymal tumours (e.g. liposarcoma) may be difficult in the absence of a complete clinical history and a reliable immunoprofile. We strongly recommend staining of any myxoid or glandular tumour of the adrenal gland for alpha-inhibin and synaptophysin (probably the currently best characterised markers of adrenocortical origin) before considering alternative (probably more common) diagnoses of metastatic adenocarcinoma or retroperitoneal tumours localised to the adrenal gland.