PMC9428640_01
(a) US showing heteroechoic intraductal portal mass (white arrow) causing bilobar IHBRD (arrow-head) and (b) no definite blood flow within the mass on Colour Doppler. (c) Coronal T2-weighted magnetic resonance imaging illustrating a heterogenous predominantly hyperintense lobulated-shaped mass arising within the common bile duct (white dashed arrow,) extending superiorly to the level of the porta. (d) oronal magnetic resonance cholangiopancreatography shows large filling defect with dilated intrahepatic bile ducts. (e) DWI (b=800s/mm2) (image c) shows mild restricted diffusion in mass (white arrow).
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Abdominal ultrasound (US) revealed a heterogeneous intraductal mass (4.3x2.3x3.4cm) producing dilatation of the common bile duct (CBD) and intrahepatic biliary channels with no evident internal flow on colour Doppler (Figures 1a and 1b). Magnetic resonance cholangiopancreatography (MRCP) revealed a lobulated lesion involving the CBD and left hepatic duct along with fusiform dilatation of the CBD. (Figure 1 c, d, e.) Diffusion restriction was noted (Figure 1f).
Post contrast computed tomography axial (a) and coronal (b) image demonstrating a mild enhancing heterogeneous mass within the common bile duct and left hepatic duct(arrow) causing compression of left portal vein seen(arrowhead). Axial (c) and coronal (d) PET CT showing mild metabolic activity within the soft tissue mass (black arrow).
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A contrast enhanced computed tomography (CECT) scan of the abdomen revealed a hypodense intraductal fusiform-shaped mass (65 mm x 45 mm x 30 mm) running along the length of the left hepatic duct (LHD), CBD, up to secondary biliary confluence, with slight heterogeneous enhancement (Figure 2a, b). Positron emission tomography (PET) scan demonstrated metabolically active soft tissue density content within the common bile duct (see Figures 2 c, d.).
Intraductal biopsy: Section shows a variably cellular tumour revealing. A) Hypocellular (white arrow) and hypercellular areas (Black arrow) with sheets of small rounded to spindle cells having inconspicuous nucleoli and scant cytoplasm. Hypocellular area reveals scattered tumour cells in a myxoid stroma - (Haematoxylin & Eosin, 4x).
B) Few of the scattered tumour cells have abundant elongated eosinophilic cytoplasm (tadpole cells - white arrows). Dense condensation of tumour cells forming cambium layer was also seen (not shown). No significant anaplasia was seen in section examined - (Haematoxylin & Eosin, 40x). On immunohistochemistry, the tumour cells show C) positive for desmin (Desmin Immunohistochemistry, 10X) and D) positive for Smooth Muscle Actin (SMA) (SMA Immunohistochemistry, 10X)
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Microscopy confirmed the presence of a variably cellular tumour consisting of hypocellular and hypercellular showing primitive mesenchymal cells of varying phases of myogenesis, sheets of small, rounded to spindled cells with inconspicuous nucleoli and scant cytoplasm (rhabdomyoblasts/Tadpole cells) (Figure 3 a, b). Immunohistochemical test was suggestive of embryonal RMS with positive stains of desmin and smooth muscle antigen (Figure 3 c, d).