The first patient was a 45-year-old woman, without significant comorbidity, who was referred to our institution for surgery. Epigastric pain with jaundice began one month previously without performance status alteration. Standard blood exams exhibited cholestasis (alkaline phosphatases 3.8 N, gama-glutamyl transpeptidases 37 N) and hyperamylasemia (1.9 N) with normal values of hemoglobin, white blood cells, platelets, carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA). Abdominal computed tomodensitometry (CT scan), magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS) of the pancreas all identified the distension of both the common bile duct (15 mm) and the Wirsung duct (6 mm), above a 28 × 20 mm irregular, hypoechoic and hypodense mass of the pancreatic head, without any lymph node or vascular invasion or distant secondary lesion detected. Based on the symptoms, a suspected diagnosis of pancreatic adenocarcinoma and a resectable mass, it was determined to proceed with primary surgery without obtaining preoperative sample biopsies. Curative whipple pancreaticoduodenectomy with regional lymphadenectomy was performed with no specific peroperative discovery and uneventful postoperative course. Histological examination of the surgical specimen revealed a pancreatic GS based on the presence of cells of myeloid lineage with positive immunostaining for CD43 myeloid-associated antigen (Figure ), whereas immunostainings for other myeloid markers (CD31, CD34, CD38, CD45, CD99, CD117), B-cell markers (CD20, CD79a), T-cell markers (CD3, CD4), commune B- and T-cell markers (CD30) and myeloperoxidase (MPO) were negative. Six weeks later, diffuse relapse occurred with the appearance of left cervical and multiple thoracic lymph nodes. After cervical biopsy, histological analysis confirmed recurrence with the same immunostaining profile. Brain tomodensitometry and bone marrow biopsy were normal. Cisplatin - cytarabin - dexamethasone-based chemotherapy was administered quickly, but the patient died due to disease dissemination one month later.
Figure 1 Fixed, paraffin-embedded tissue sections of i) pancreatic invasion (A, case n°1, magnification at ×100) of medium sized cells, with CD43 positive expression signing myeloid lineage, inset shows contiguous lymph node with high CD43 expression (more ...)
The second patient was a 19-year-old woman, without significant comorbidity or any alcohol consumption, who presented at our institution for epigastric pains combined with hyperamylasemia (1.7 N) and hyperlipasemia (7.8 N). Hemogram, hepatic enzymes, C-reactive protein, CEA and Ca 19.9 values were normal. The abdominal CT scan showed a 9-mm Wirsung duct dilation (Figure ) within the 30-mm mass of the pancreatic head (Figure ), the tumoral or inflammatory nature of which was uncertain. After conventional medical treatment for pancreatitis, the symptoms disappeared, allowing hospital discharge with additional morphological outpatient exams scheduled. Due to early recurrent epigastric pain episodes, combined with hyperlipasemia, she was re-admitted. EUS revealed an 11-mm celiac lymph node with a 9-mm Wirsung duct dilation and no clear pancreatic mass, whereas pancreatic MRI identified a moderately low signal intensity on T1-weighted images, middle-high signal intensity on T2-weighted images, and minimal enhancement on post-gadolinium images, consistent with the diagnosis of hypovascular solid tissues. Normal pentetreotide scintigraphy and the chromogranin A value ruled out the diagnosis of neuroendocrine tumor. Due to the absence of a clear diagnosis, persistent symptoms and the discordance between the exams that had been performed, the decision was made to proceed with a surgical exploration, revealing diffuse peritoneal carcinomatosis combined with an unresectable and inflammatory 30-mm pancreatic mass. Histological analysis of the pancreatic mass and peritoneal biopsies revealed extramedullar myeloid tumoral cells with immunohistochemistry positive for MPO, CD43, and CD34 (Figure ), as well as CD117 and CD45, and negative for CD79a, CD3, CD2, CD4, CD8 and CD68, leading to the diagnosis of pancreatic GS. The brain CT scan and bone marrow biopsy were normal. An induction cytarabin-based chemotherapy was begun quickly, leading to a complete morphological response after three consolidation cycles. Eight months later, left inguinal lymph node recurrence was diagnosed. Second-line amsacrine-cytarabin-based chemotherapy achieved a partial morphological response. Due to tumoral progression four months later, third-line clofarabine-based chemotherapy was administered with an optimal response that allowed bone marrow transplantation two months later. Diffuse peritoneal and hepatic recurrence was diagnosed based on PET scanning six months later, leading to palliation.
Figure 2 Abdominal computed tomodensitometry, with injection of contrast product, portal sequence. Axial (A) projection showing Wirsung dilatation (arrow head). Axial (B) and frontal (C) projections showing low density pancreatic mass (arrow heads), case n°2. (more ...)