We present the case of a 48-year-old male with pain in the upper abdomen and jaundice
for 2 months. Minimally deranged liver function tests were seen in the form of mild
elevation of total serum bilirubin – 1.16 mg/dL (N: 0.3–1.2 mg/dL) and raised alkaline
phosphatase levels – 307 IU/L (N: 20–140 IU/L) with normal serum glutamic pyruvic
transaminase/serum glutamic-oxaloacetic transaminase 35/20 IU/L. He was evaluated
with contrast-enhanced computed tomography (CECT) and magnetic resonance cholangiopancreatography
(MRCP). CECT revealed multicystic mass in the head of the pancreas [Figure 1]a]. In view of the raised bilirubin/cholangitis, endoscopic retrograde cholangiopancreatography
with stenting was done. MRCP confirmed the presence of a honeycomb cystic lesion in
the head of the pancreas having communication with the main pancreatic duct with mild
dilatation of the side-duct branches [Figure 1]b]. A provisional diagnosis of branch-duct intraductal papillary mucinous neoplasm
(IPMN) was made considering the morphology of the lesion. After taking due consent
and fitness, he underwent open classic pancreatoduodenectomy. Postoperative histopathological
examination revealed a highly infiltrative tumor composed of cysts of variable sizes
separated by paucicellular desmoplastic stroma. The epithelial cells lining these
cysts were cuboidal to low columnar and showed moderate nuclear pleomorphism and atypia.
Frequent mitotic figures, including atypical ones, were seen (10–12/10 high-power
field). At places, the nuclear stratification of the lining epithelial cells was noted.
The lining epithelial cells of cysts showed positive staining for p53 and membranous
staining for carcinoembryonic antigen, making the diagnosis of microcystic variant
of pancreatic adenocarcinoma [Figure 2]a],[Figure 2]b],[Figure 2]c],[Figure 2]d] over IPMN. Pancreatic ductal adenocarcinoma (PDAC) with large-duct type cysts is
one of the morphologic variations of PDACs, which is characterized by more dilated
malignant ducts forming a microcystic feature. The size of cysts is small, usually
0.5–0.7 cm in diameter, occasionally exceeding 1 cm and can mimic IPMN or microcystic
serous cystadenoma on imaging.
Figure 1: (a) Contrast-enhanced computed tomography showing microcystic mass (arrow)
in the pancreatic head. (b) Magnetic resonance cholangiopancreatography confirming
a honeycomb cystic lesion in the head of the pancreas having communication with the
main pancreatic duct with mild dilatation of the side-duct branches
Figure 2: (a) Low-power microphotograph showing cyst of variable size with epithelial
lining, separated by paucicellular desmoplastic stroma (H and E, ×20). (b) Further
magnification shows that the cyst is lined by cuboidal epithelial cells. The small
irregular angulated glands are also noted (H and E ×100). Inset high-power image (×40)
shows moderate nuclear atypia of lining epithelial cells and occasional atypical mitotic
figures. (c and d) The lining epithelial cells of cysts show nuclear expression of
p53 (×100) and membranous staining for carcinoembryonic antigen (×40)
PDAC typically presents as an irregular solid tumor with a scirrhous character resulting
from a prominent desmoplastic reaction. The incidence of PDAC with cystic changes
ranges from <1% to 8%. PDACs with cystic change are uncommon and may occur by means
of the four following mechanisms – (i) obstruction of the pancreatic duct by the tumor
resulting in the formation of retention cysts localized outside the tumor periphery,
(ii) coexisting acute pancreatitis resulting in pseudocyst formation localized outside
the tumor, (iii) microcystic appearance caused by marked ectasia of the invasive gland
and referred to as the “large-duct type,” and (iv) necrosis within the tumor. The
large-duct type ectasia within the tumor was seen in the present case.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms.
In the form, the patient has given his consent for his images and other clinical information
to be reported in the journal. The patient understands that his name and initial will
not be published, and due efforts will be made to conceal his identity, but anonymity
cannot be guaranteed.
