Cytopathology of anaplastic carcinoma of the pancreas: Review of a rare entity and description of a variant with signet ring cell features

Abstract

Anaplastic carcinoma of the pancreas (ACP) is a rare and aggressive variant of pancreatic ductal adenocarcinoma (PDAC). Several studies have attempted to characterize this subtype through case series or single case reports; however, ACP remains underrecognized by cytopathologists in particular, and often lumped under the umbrella of classic PDAC. Here, we review the most up to date data that literature provides about ACP, to bring familiarity with this entity to the cytopathology practice, and to elucidate the role cytopathologists can play in recognizing and diagnosing this subtype on pancreatic aspiration biopsy, before surgical resection. We also describe a rare case of ACP, demonstrating signet ring cell features, that was diagnosed on fine needle aspiration of a pancreatic mass.

Primary signet ring cell carcinoma of the pancreas: Cytopathology review of a rare entity

“…It is worth mentioning that recently, we described a variant of primary anaplastic carcinoma of the pancreas with signet ring cell morphology . In the reported case, the neoplastic cells were enlarged with ample vacuolated cytoplasm, and hyperchromatic nuclei with irregular contours and prominent nucleoli, admixed with pleomorphic mononuclear cells and multinucleated giant cells . Other scenarios that can mimic signet ring cells carcinoma in the pancreas include, but are not limited to, metastatic SRCC of another organ to the pancreas (Figure ), melanoma with signet ring cell features and signet ring cell lymphoma .…”

“…It is worth mentioning that recently, we described a variant of primary anaplastic carcinoma of the pancreas with signet ring cell morphology . In the reported case, the neoplastic cells were enlarged with ample vacuolated cytoplasm, and hyperchromatic nuclei with irregular contours and prominent nucleoli, admixed with pleomorphic mononuclear cells and multinucleated giant cells .…”

Effect of chemotherapy on prognosis in patients with primary pancreatic signet ring cell carcinoma: A large real-world study based on machine learning

“…As a subtype of pancreatic ductal adenocarcinoma, PSRCC is very rare [8]. To our best knowledge, only 21 cases were reported in the literature [8,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. The value of chemotherapy was still unclear for the lack of high-quality clinical evidence and large samples of multicenter clinical studies.…”

One size does not fit all for pancreatic cancers: A review on rare histologies and therapeutic approaches

“…On the contrary, spindle cells tend to arrange in a storiform pattern and to be more uniform, ovoid to spindle shaped. Furthermore, areas of infiltrating ductal adenocarcinoma at the periphery of the lesions, squamous differentiation, and areas of phagocytic activity are frequently observed[ 73 , 81 , 82 ]. Although this bizarre morphology, electron microscopy, and above all, immunohistochemistry analysis have demonstrated the epithelial origin of UC neoplastic cells.…”