**Figure 5.**

*Glutamine synthetase shows positive cytoplasmic staining (a), CD10 antibody shows positive canalicular staining (b).*

The histopathological diagnosis of SH-HCC is usually easy in cases with explant and resection. However, tru-cut biopsies, which represent a small part of the tumor, may have diagnostic difficulties. These diagnostic difficulties are due to both the heterogeneity of the tumor and its similar morphological appearance to NAFLD with advanced fibrosis. A tru-cut biopsy from focal nodular hyperplasia (FNH) with fatty changes sometimes can be confused with a diagnosis of nodular and well differentiated SH-HCC. This difference between the diagnosis in the tru-cut biopsy and the resection material should not be interpreted as a misdiagnosis. Before interpreting it as an erroneous diagnosis, it should be remembered that this diagnostic difference is due to the heterogeneous and fat-containing nature of the tumor. Pathologists should remember that bile duct proliferation, presence of central scar (histologically and radiologically), and thick-walled abnormal vascular structures in the fibrous septa are more common in FNH when examining this tru-cut biopsy. Since fibrosis can be seen in both SH-HCC and FNH, it may not clarify the differential diagnosis. Non-invasive border and immunohistochemical staining (sinusoidal CD34 staining, glypican-3 positivity and diffuse glutamine synthetase staining) may be helpful in the differential diagnosis of steatohepatitis [8, 11, 68, 72]. Differentiation from classical HCC can be made by evaluating morphological and immune markers together [68]. In spite of all this, it would be appropriate to consult a pathologist experienced in liver pathology in cases where tumor specification could not be made.

The relationship between NAFLD, NASH, and HCC (especially SH-HCC) is now known. Adequate tumor sampling should be performed in resection materials, explants, particularly when identifying subtypes of large-diameter HCCs. It should be noted that classical HCC and other subtypes, including SH-HCC, have a heterogeneous histomorphology. While patients with metabolic syndrome, insulin resistance, obesity, fatty liver and steatohepatitis are followed up, careful radiological examination should be performed for SH-HCC that may develop from this background. In other words, the terminology of "neoplastic steatogenesis" should be kept in mind.
