Fine-needle aspiration of intrapancreatic accessory spleen: Cytomorphologic features and differential diagnosis

Autor: Momin T. Siddiqui, Christopher L. Owens, Ralph H. Hruban, Armanda D. Tatsas, Syed Z. Ali
Rok vydání: 2012
Předmět:
Zdroj: Cancer Cytopathology. 120:261-268
ISSN: 1934-662X
DOI: 10.1002/cncy.21185
Popis: BACKGROUND: Intrapancreatic accessory spleen (IPAS) is a rare benign lesion of the pancreas that frequently clinically and radiographically mimics a solid neoplasm. Very rarely, epidermoid cysts may form in IPAS and be mistaken for a cystic neoplasm of the pancreas on radiographic imaging. IPAS and epidermoid cyst involving intrapancreatic cyst (ECIPAS) are benign, and, if recognized, do not require surgical intervention. There are few reports of the cytopathologic features of IPAS diagnosed by fine-needle aspiration (FNA). METHODS: Here we report a series of 6 cases of endoscopic ultrasound (EUS)-guided FNA of IPAS, 3 of which had histological confirmation, including 1 case of histologically confirmed ECIPAS. RESULTS: Cytomorphologic features of IPAS include a polymorphous population of hematopoietic cells, including lymphocytes, eosinophils, histiocytes, plasma cells, and red blood cells, admixed with numerous small blood vessels representing splenic sinusoids. CD8 immunostaining of cell block or core biopsy material highlights splenic endothelial cells and confirms the diagnosis. FNA of ECIPAS reveals predominantly macrophages and proteinaceous debris. CONCLUSIONS: Diagnostic pitfalls include pancreatic neuroendocrine tumor. If IPAS is recognized as a diagnostic consideration on EUS-FNA, unnecessary surgical resection may be avoided. Cancer (Cancer Cytopathol) 2012;120:261-8. V C 2012 American Cancer Society. Accessory spleens are estimated to be present in approximately 10% of the general population and 15%20% of accessory spleens are present in the pancreatic tail, 1 as portions of splenic tissue become trapped in the dorsal pancreatic bud during embryologic development. IPASs are benign and do not require surgical intervention unless the spleen is involved by a secondary process such as lymphoma or idiopathic thrombocytopenic purpura. The fine-needle aspiration (FNA) findings of intrapancreatic accessory spleen (IPAS) have rarely been reported. 2-4 Epidermoid cyst in an IPAS (ECIPAS) was first reported by Davidson et al 5 in 1980, and fewer than 25 cases have been reported in the English literature. 6-10 The FNA findings of a histopathologically confirmed ECIPAS have not been previously described to our knowledge. With the increased use of imaging for screening, diagnosis, and monitoring of many conditions, as well as use of multiphase computed tomography (CT) and magnetic resonance imaging (MRI) with improved contrast and spatial resolution, the incidental detection of masses in many organs, including pancreas, has
Databáze: OpenAIRE
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