PMC8714389_01
(a) Computed tomography image (pancreatic parenchymal phase). A slightly enhanced, relatively homogeneous tumor can be seen in the pancreas head (arrowheads). Multiple enlarged peripancreatic and mesothelial lymph nodes (arrows) are visible. (b) Magnetic resonance cholangiopancreatography image showing bile duct dilatation.
CRIPA2021-7439148.001.jpg
PMC8714389_01_CRIPA2021-7439148.001.jpg
fig1
Abdominal computed tomography (CT) with enhancement showed a 44 mm, gradually enhanced mass with multiple enlarged lymph nodes, including peripancreatic and mesenteric nodes (Figure 1(a)). Magnetic resonance cholangiopancreatography (MRCP) revealed dilatation of the common bile duct (Figure 1(b)).
Increased (a, arrowheads) monocytes and neutrophils with degranulation/hypogranulation in which (b, arrows) MPO shows negative or weakly positive in peripheral blood ((a) May-Grunwald stain, (b) myeloperoxidase stain). Flow cytometry of the peripheral blood shows a few scattered blastoid cells with CD45/side scatter gating (c, arrow). (d) With forward versus slide scatter gating, (e) underexpression of CD11c and (f) aberrant expression of CD56 are shown for monocyte subset.
CRIPA2021-7439148.002.jpg
PMC8714389_01_CRIPA2021-7439148.002.jpg
fig2
An increase in monocytes (>1 x 109/L), atypical neutrophils, enlarged PLTs, polychromatic erythroblasts, and atypical monocytes were seen in the peripheral blood (Figures 2(a) and 2(b)); hence, hematological malignancy was suspected and a bone marrow examination was planned. Flow cytometry of the peripheral blood was performed, showing a few blastoid cells with CD45/side scatter gating and aberrant expression of CD56/underexpression of CD11c for monocyte subsets with forward versus slide scatter gating (Figures 2(c)-2(f)).
(a) Cut section of the pancreatic head showing an ill-circumscribed whitish mass (arrowheads) and multiple swollen peripancreatic lymph nodes. Microscopic image showing a (b) rather circumscribed tumor border (dotted line) and (c) discohesive and round tumor cells, often with marked cleaved nuclei. Tumor cells with remaining scattered pancreatic acinar cells (arrowheads) are seen (d). Immunohistochemistry showing some tumor cells are positive for (e) CD163 and most tumor cells are positive for (f) myeloperoxidase and (g) CD33 (immunohistochemistry for (e) CD163, (f) myeloperoxidase, and (g) CD33).
CRIPA2021-7439148.003.jpg
PMC8714389_01_CRIPA2021-7439148.003.jpg
fig3
During the autopsy, a whitish mass was found, involving the pancreatic head and peripancreatic lymph nodes (Figure 3(a)). Microscopic examination revealed diffuse infiltration of the mass by round cells containing atypical nuclei with marked cleavage (Figures 3(b)-3(d)). Some, but not all, tumor cells were positive for CD68 and CD163 (Figures 3(e)-3(g)).
(a) Markedly hypercellular bone marrow with discohesive, round tumor cells similar to those seen in the pancreatic head. Tumor cell emboli at alveolar wall with fibrous thickening of pulmonary vasculature (b, c). Leukemic cells are indicated by the arrows (d).
CRIPA2021-7439148.004.jpg
PMC8714389_01_CRIPA2021-7439148.004.jpg
fig4
The bone marrow showed a marked hypercellular state in which >50% of the cells were the same as those seen in the pancreatic head (Figure 4(a)). Diffuse fibrotic thickening of small veins and interalveolar fibrinous exudates were observed, suggesting a PTTM-like condition (Figures 4(b)-4(d)).