Epithelial inclusion cyst (epidermoid cyst) formation with epithelioid cell granuloma in an intrapancreatic accessory spleen

The histologic characteristics of a case of epidermoid cyst formation with an epithelioid cell granuloma that developed in intrapancreatic accessory spleen were investigated, with the aim of clarifying its origin as well as etiologic factors. The patient, a 48-year-old male, was found to have a cystic lesion in the tail of the pancreas and renal cell carcinoma (clear cell carcinoma) during a medical check up. The pancreatic mass appeared to be a so-called "mucinous tumor" on imaging, and combined resection of the body and tail of the pancreas and the spleen was performed together with a left nephrectomy. The lesion in the tail of the pancreas was then demonstrated to have accessory splenic tissue with cyst formation in its central region. The cystic wall was covered with stratified squamous epithelium and ductal epithelium with squamous metaplasia, and pancreatic islet cells were evident at various sites within the accessory spleen. Formation of epithelioid cell granuloma tissue was observed around the cysts. The epithelium of the cyst was positive for CA19-9 and negative for antibodies against mesothelial cells, whereas the pancreatic island cells were positive for insulin. These results suggested that cystic epithelium in the accessory spleen could be derived from pancreatic duct epithelium. Frequent recurrence of chronic inflammation and epitheloid cell granuloma formation may have resulted from an aberration of the ectopic remaining pancreatic tissue in the spleen.     

Epithelial splenic cysts in an intrapancreatic accessory spleen and spleen

A rare case of cysts simultaneously occurring in the intrapancreatic accessory spleen and spleen in a 49-year-old female is reported. The patient underwent distal pancreatomy for a cystic tumor of the pancreas, and a splenectomy. A multilocular cyst (4.3 x 2.6 cm) in an accessory spleen at the pancreas tail, and a solitary cyst (1.2 x 0.9 cm) of the spleen were found. The cyst in the intrapancreatic accessory spleen was lined by non-keratinizing stratified squamous epithelium, and the spleen cyst by a single layer of flat epithelium; these lining cells were positive for Alcian blue stain and periodic acid-Schiff reaction, and were immunohistochemically positive for cytokeratin, HBME-1 and Sialyl-Tn. Epithelial membrane antigen, carcinoembryonic antigen and CA19-9 were positive in the accessory spleen cyst but were negative in the spleen cyst. An electron microscopic examination of the flat epithelium of the spleen cyst revealed numerous microvilli on the surface, cytoplasmic microfilaments, and a number of tight junctions between adjacent cells. These features suggested that the two cysts differ in nature, and origin; the accessory spleen cyst may be an embryonic inclusion of the pancreas duct while the spleen cyst may be an inclusion cyst of the mesothelium.     

Epithelial inclusion cysts in an intrapancreatic accessory spleen

A 38 year old male underwent distal pancreatectomy for benign cystic pancreatic tumor. The pancreas tall contained a 2.3 x 2.1 cm accessory spleen associated with multiple epithelial inclusion cysts. The cysts were of varying sizes (max: 1.4 cm), lined by non-keratinizing squamous epithelium with a few mucin-producing cells, and filled with serous material. This is the fifth reported case of so-called'epidermoid'cysts in the intrapancreatic accessory spleen.     

Serous cystic neoplasm in an intrapancreatic accessory spleen

Serous cystic neoplasm (SCN) of the pancreas is a benign epithelial neoplasm, except in extremely rare malignant cases. Development of SCN in tissues other than the pancreas has been never reported. Here we present the first reported case of SCN in an intrapancreatic accessory spleen (IPAS). A 54‐year‐old female patient with von Hippel‐Lindau (VHL) syndrome was found to have pancreatic tail mass. Pathologically the 25‐mm solid mass was an IPAS showing proliferation of clear cuboidal tumor cells without atypia, forming numerous small cysts. The tumor cells were rich in cytoplasmic glycogen and distributed in the splenic tissue almost diffusely. Immunohistochemically, tumor cells were positive for cytokeratins, MUC6, and neuron‐specific enolase, and negative for neuroendocrine markers. From these findings, we diagnosed the lesion as SCN in IPAS. This tumor is suggested to develop as a VHL‐associated SCN from coexisting pancreatic tissue in IPAS rather than as a metastatic tumor.     

Fine-needle aspiration of intrapancreatic accessory spleen, mimic of pancreatic neoplasms

Intrapancreatic accessory spleen (IPAS) is a congenital abnormality, which mimics neoplasm. Distinguishing IPAS from pancreatic neoplasm/malignancy is extremely important from a treatment perspective. We report the case of a 67-year-old asymptomatic man who had a 1.3-cm, incidentally detected, pancreatic tail mass. The mass was round, well-circumscribed, and hypervascular with uniform enhancement. The image findings were highly suggestive of a pancreatic endocrine neoplasm. An endoscopic ultrasound-guided fine-needle aspiration was performed. Conventional smears revealed a polymorphous population of lymphocytes admixed with a subset of other inflammatory cells. Hematoxylin-eosin–stained cell block sections showed conspicuous thin-walled blood vessels in addition to inflammatory cells. Immunostaining for CD8 demonstrated strong positivity in endothelial cells of the thin-walled vessels. By correlating the cytologic findings with the result of immunostaining, we rendered the diagnosis of IPAS. Our experience supports the view that endoscopic ultrasound-guided fine-needle aspiration may enable a reliable, preoperative diagnosis of IPAS and thus prevent unnecessary surgery.     

Epidermoid cyst derived from an accessory spleen in the pancreas. A case report with literature survey.

A rare case of splenic epidermoid cyst (SEC) of the pancreas discovered in a 32-year-old Japanese female is reported. The lesion, 5 x 6 cm in size including caseous material and serous fluid in the lumen, was discovered by ultrasonography and computed tomography at the tail of the pancreas and was easily removed. Histopathologically, the cystic wall consisted of three components: the inside was lined by mature squamous epithelium with keratinization, the middle layer consisted of splenic pulp with a sinus structure, and the peripheral layer was dense fibrous connective tissue in which some involutional pancreatic ducts and islets were recognized. The literature about SEC of the pancreas is discussed in comparison with other types of epidermoid cyst including lymphoepithelial cyst and dermoid cyst in the pancreas.     

Intrapancreatic accessory spleen: A case report and review of literature

Intrapancreatic accessory spleen is not an uncommon entity and usually located in the tail of the pancreas. Most of them are asymptomatic and incidental findings on radiologic study or at autopsy. On imaging study, it appears to be a well‐defined, solitary, and hypervascular lesion; therefore, it may be confused with pancreatic neoplasms, such as neuroendocrine neoplasm, well‐differentiated adenocarcinoma, solid pseudopapillary tumor, or metastatic tumor to the pancreas. As such, the diagnostic fine‐needle aspiration biopsy of the lesion may be performed. Several case reports describing cytological features of the lesion have been published in recent years. Among them, the most commonly identified cytological findings are sheets of a heterogeneous population of lymphocytes and prominent traversing blood vessels. Herein, we report an unusual EUS‐FNA case of intrapancreatic accessory spleen. In addition to above previously well‐described cytological features, our case revealed many cells with fine granular chromatin and areas with pseudo rosette‐like architecture, mimicking and engendering the differential diagnosis of pancreatic neuroendocrine tumors. Although cytological findings of our case are rare, they may extend our current knowledge and provide additional differential diagnostic information for this entity. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.     

Epidermoid cyst of the spleen. Presentation of a case

Cystic lesions of the spleen are unusual. They are classified essentially as: parasitic or nonparasitic, based on their etiology, and true or pseudo based on the presence or absence of lining epithelium. The pathogenesis of true cysts is unknown and numerous hypotheses are given by different Authors. After a short review of the literature, the Authors describe the clinical and pathological data of a case of epithelial (epidermoid) splenic cyst occurs in a 12-year-old woman. The Authors put forward some personal observations on pathogenesis, still doubtful, by means of histochemical and immunohistochemical study.     

Wandering accessory spleen

Summary A patient with an excessively mobile accessory spleen detected on ultrasound examination is reported in whom a normally located spleen was also found. Sonographic and colour Doppler imaging criteria were used for making the specific diagnosis. The large accessory spleen has been demonstrated at different sites within the abdomen on subsequent follow-up sonographic examinations. The splanchnic flow pattern obtained from the long vascular pedicle of the accessory spleen indicated normal perfusion. Since the perfusion of the wandering accessory spleen was not compromised by torsion, and the patient refused surgical intervention, a conservative approach was considered to be appropriate.

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Rate accessoire migratrice

Résumé Les auteurs rapportent le cas d'un patient porteur d'une rate accessoire excessivement mobile découverte lors d'un examen échographique et chez qui une rate normalement située a été également trouvée. Des critères d'imagerie par échographie et au Doppler couleur ont été utilisés pour le diagnostic spécifique. La volumineuse rate accessoire a été trouvée en différents sites de l'abdomen durant le suivi échographique. Le flux splanchnique venant du long pédicule vasculaire de la rate accessoire montrait une perfusion normale. Comme la perfusion de la rate accessoire migratrice n'était pas compromise par une torsion et comme le patient refusait toute intervention chirurgicale, un traitement conservateur a été considérée comme suffisant.

     

Radiologic evaluation of epidermoid cyst

Optimal radiologic investigation greatly improves surgical outcome in cases of epidermoid cyst. As the lesion is benign but will recur if total excision is not accomplished, the surgeon must be prepared to resect the entire capsule and not simply drain the cyst. The contribution of neuroimaging and other diagnostic procedures to the preoperative evaluation of a man with posterior fossa cyst is reported.     

Intraosseous epidermoid inclusion cyst in a great toe. A case report and review of the literature

Epidermoid inclusion cysts are benign lesions that occasionally occur in the distal phalanges of the fingers but are less frequently identified and underreported in the toes. We describe a 55-year-old man with a history of work-related trauma followed by painful expansion of his right great toe, resulting in great anxiety. Imaging studies revealed a radiolucent lesion in the distal phalanx of his right hallux. Clinical differential diagnoses included the possibility of an intramedullary inclusion cyst and other various radiolucent lesions. During surgery, a cystic lesion that contained creamy material was discovered. Frozen section diagnosis of the lesion was an intraosseous epidermoid inclusion cyst. The lesion was removed and the patient recovered uneventfully. Although it has been reported that an unduly large number of phalangeal cysts have been treated by amputation, the judicious use of intraoperative frozen sections can prevent this scenario.     

Mycosis fungoides in an epidermoid cyst

A patient with mycosis fungoides is described in whom two excised epidermoid cysts showed mycotic involvement.     

Intracranial epidermoid cyst in a horse

An intracranial epidermoid cyst was diagnosed in a Haflinger gelding aged 12 years suffering from episodes of neurological disturbance, apathy and fever. The extracerebral cyst was located in the region of the tentorium cerebelli and measured 9 x 8 x 5 cm. It displaced the cerebral hemispheres anteriorly and compressed the cerebellum and brainstem underneath. Histologically, the cyst was lined by keratinizing, stratified squamous epithelium and contained keratin scales, debris, focal haemorrhages, and degenerating inflammatory cells. The epithelium was supported by a vascularized fibrous capsule that firmly adhered to the dura mater. Multifocal haemorrhages and moderate lymphohistiocytic infiltrations were present in the capsule. The basement membrane was disrupted focally, and single or clustered cytokeratin-positive epithelial cells were detected in the fibrous capsule, suggesting a possible transition to malignancy.