Patient: Flynn.
Gross Examination: The submission consisted of a 90 x 60 x 50 mm poorly defined mass within a liver lobe, a 25 x 18 x 12 mm
irregular sample of liver margin without obvious anatomic orientation, a 12 x 7 mm diameter core sample of the right medial liver
lobe, a 7 x 3 mm diameter sample of duodenum, a 5 x 2 x 1 mm sample of distal jejunum, a 20 x 20 x 15 mm mesenteric mass
within fatty tissue, and a 12 x 1 mm diameter left renal needle core biopsy. The presumed surgical margins of the liver lobe
mass were inked and multiple sections taken from this tissue, along with the other submitted samples.
Histopathology: The intestinal samples were assessed according to the criteria for duodenum described by the WSAVA
Gastrointestinal Standardisation Group.
Liver mass: The mass is an expansile non-encapsulated neoplasm composed of variably sized lobules of epithelial cells.
These form thick anastomosing cords that are separated by sinusoidal spaces and fine fibrous stromal tissue. The cords
resemble normal hepatocyte plates and occasionally surround large vessels resembling central veins, but are irregularly
arranged with large vaguely reticular areas of hepatocyte vacuolation, occasional individual cell necrosis and a focus of fibrosis.
Portal tracts are only seen close to the tumour margin (presumed entrapped normal structures), and there are foci of
extramedullary haematopoiesis (EMH) and lymphocytes, plasma cells and macrophages with yellow/green/golden pigment
(bile/lipofuscin and haemosiderin) scattered throughout the tumour. The neoplastic cells are cuboidal with moderate amounts of
eosinophilic cytoplasm. Their nuclei have mild variation in size and shape (round to irregular) with stippled chromatin and
occasionally distinct nucleoli; some bi- or multi-nucleated cells are seen. Mitotic figures are uncommon (2 per 10 400x fields).
The adjacent liver is compressed with multifocal vascular dilation, multifocal hepatocyte vacuolation or atrophy, some areas of
nodular hyperplasia, portal fibrosis and biliary/vascular proliferation, focal thrombosis, multifocal inflammatory cells and EMH as
described above, and neutrophils in sinusoids. Sections from the inked margin contain only areas of nodular hyperplasia.
Liver margin: Sections from this sample contain vaguely defined areas of widely and irregularly spaced portal tracts and central
veins, separated by irregular and sometimes thick cords of hepatocytes that may be vacuolated. There are no mitotic figures.
There are similar foci of inflammation and EMH as described above.
Right medial liver lobe: Sections from this sample contain similar areas of neoplastic hepatocyte cords as described for the liver
mass. There is a small area of thrombosis in one section.
Duodenum: The sample is well preserved, and all layers except the serosa are distinct. Long slender uniform villi are present in
variably well-oriented sections. These have a normal layer of columnar epithelium with approximately 2-12 goblet cells per 100
enterocytes and 7-20 intraepithelial lymphocytes per 400x stretch of epithelium. Central lacteals are not seen in longitudinal
section, but do not appear to represent more than 25% of the width of the villous lamina propria.
The crypts are aligned perpendicularly to the surface, with narrow luminal area and columnar epithelial lining containing
occasional goblet cells. They rarely contain a neutrophil or eosinophil. The mucosa has a narrow band of stroma, with 1-2
stromal cells separating crypts.
In the villous lamina propria, approximately 25% of the area of one 400x field is occupied by lymphocytes and plasma cells.
Between the crypts there are 1-2 lymphocytes or plasma cells. There are about 4-20 eosinophils and 0-1 neutrophils per 400x
field. The other intestinal layers seen are within normal histological limits.
Distal jejunum: The sample is well preserved and all layers except the serosa are distinct. Long slender uniform villi are present
in variably well-oriented sections. These have a normal layer of columnar epithelium with approximately 10-50 goblet cells per
100 enterocytes and 15-20 intraepithelial lymphocytes per 400x stretch of epithelium. Central lacteals are rarely seen, and
occupy 25-50% of the width of the villous lamina propria.
The crypts are aligned perpendicularly to the surface, with narrow luminal area and columnar epithelial lining containing
occasional goblet cells. The mucosa has a narrow band of stroma, with 1-2 stromal cells separating crypts.
In the villous lamina propria, approximately 25% of the area of one 400x field is occupied by lymphocytes and plasma cells.
Between the crypts there are 1-2 lymphocytes or plasma cells. There are about 15-20 eosinophils and 0-14 neutrophils per 400x
field. The other intestinal layers seen are within normal histological limits.
Mesenteric mass: This is a nodule composed of areas of neoplastic hepatocyte cords similar to those described for the liver
mass. The cells are a little more pleomorphic and less well organised, with a slightly higher mitotic index (6 per 10 400x fields).
This is bounded by a layer of fibrous tissue, separating it from adjacent mesenteric adipose tissue. No recognisable lymphoid