Anaplastic Carcinoma Arising in a Mucinous Cystic Neoplasm Masquerading as Pancreatic Pseudocyst

Abstract

Mucinous cystic neoplasms (MCN) of the pancreas can vary from benign to premalignant and malignant. Preoperative diagnosis is essential to offer the patient appropriate treatment. Occasionally these cases may harbor anaplastic carcinoma while clinically masquerade as a pseudocyst. Here in, we report an unusual case of a 37-year old female presented with recurrent abdominal pain that was suspected clinically and by imaging studies to have a pseudocyst. EUS-FNA with internal drainage of the cyst was performed. Cytological evaluation of the cyst fluid showed numerous inflammatory cells composed mainly of many neutrophils admixed with macrophages reminiscent of the usual pseudocyst content but there were scattered rare dyscohesive malignant cells which were highly pleomorphic with multinucleation. Immunostains on the cell block showed immunoreactivity of these cells including the multinucleated cells for Cam 5.2 and AE1/AE3 and focally for Ber-Ep4, Moc -31, and CA19-9. The subsequent resection confirmed the presence of anaplastic (undifferentiated) carcinoma (AC) arising in a MCN of the pancreas. Diagn. Cytopathol. 2016;44:538-542. © 2016 Wiley Periodicals, Inc.

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

“…6 ACP occurs most commonly in the head of the pancreas, 6,18 but it has been also described in the pancreatic body. 6,18,19 With a pooled sensitivity of 85% and 89% and pooled specificity of 98% and 99% in diagnosing pancreatic malignancies according to two meta-analyses studies, 20,21 EUS-FNA has been established as the gold standard initial approach for the assessment of pancreatic masses. One case series of ACP reported that four out of five patients (80%) were diagnosed with ACP on EUS-FNA.…”

“…Reported EUS features of ACP include a hypoechoic tumor, with solid or mixed solid and cystic components and poorly defined borders; however, it can also present as a well‐defined homogeneous mass in some cases . ACP occurs most commonly in the head of the pancreas, but it has been also described in the pancreatic body …”

“…Management of ACP varies widely in literature, and to date, no universal clinical/surgical protocols have been suggested . Some reported ACP cases were approached with chemotherapy alone, others with neoadjuvant chemotherapy followed by surgery, or surgery alone .…”

“…45 Owing to its' exaggerated pleomorphic morphology, striking nuclear atypia, cytoplasmic vacuoles, and occasional or frank sarcomatous growth pattern, the differential diagnosis of ACP on FNA is wide, and it includes Malignant Melanoma and Amelanotic Melanoma, Hodgkin's lymphoma, Anaplastic large cell lymphoma, Choriocarcinoma, poorly differentiated hepatocellular carcinoma, epithelioid sarcoma, pleomorphic rhabdomyosarcoma, pleomorphic liposarcoma, and malignant fibrous histiocytoma, in addition to metastatic anaplastic carcinoma from other organs (such as the lung and thyroid gland). 7,25 Although ACP has been shown to exhibit spindle cell, neuroendocrine 6,27 and squamous cell differentiation, 25 Management of ACP varies widely in literature, 6,18,19,22,23,27,46,47 and to date, no universal clinical/surgical protocols have been suggested. 47 Some reported ACP cases were approached with chemotherapy alone, 6,22,47 others with neoadjuvant chemotherapy followed by surgery, 6 or surgery alone.…”

Anaplastic carcinoma of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration: a case report and review of the literature

“…We performed a literature search with the terms “Anaplastic carcinoma pancreas” and “EUS-FNA”, using PubMed database for the period from 2006 to September 2016. We found seven reports of 19 cases of ACP during that period diagnosed by EUS-FNA (including our patient; Table 1 ) [ 5 – 11 ]. In most of the cases, the tumors were shown as hypoechoic and heterogeneous by EUS.…”