Epidermoid cyst in intrapancreatic accessory spleen: radiological findings including superparamagnetic iron oxide-enhanced magnetic resonance imaging

Imaging features of epidermoid cysts in intrapancreatic spleen: a single center study of 24 patients

OBJECTIVE

This study aims to investigate the imaging features of epidermoid cysts within intrapancreatic accessory spleen (ECIPAS) to benefit the differential diagnosis of pancreatic cystic lesions.

METHODS

We retrospectively reviewed the clinical, radiological and pathological data of 24 patients with pathologically confirmed ECIPAS. All cases underwent abdominal contrast-enhanced computed tomography (CE-CT) scans, with 4 cases further undergoing magnetic resonance cholangiopancreatography (MRCP). The imaging features of the lesions were analyzed.

RESULTS

The majority of the patients were young to middle-aged with no apparent clinical symptoms. Over half of the masses exhibited circular, oval or unilocular architectures. On plain CT, the masses primarily displayed indistinct margins with an average diameter of 3.0 ± 1.1 cm. Nineteen lesions were situated in the pancreatic tail, 1 in the head, 1 in the head-body junction, and 3 in the body. In the arterial phases of enhanced CT scans, the lesions exhibited varying degrees of enhancement: slight enhancement (n = 11), significant enhancement (n = 5), and no discernible enhancement (n = 8) compared to pancreatic parenchyma. On MRCP scan, all four lesions showed hyperintense on T2-weighted imaging (T2WI).

CONCLUSION

ECIPAS is a rare benign lesion, with nearly half exhibiting slightly uneven enhancement on contrast-enhanced CT scans. Usually, the solid-portion-enriched lesions show similar enhancement to that of the spleen, aiding in the precise preoperative diagnosis. ECIPAS can manifest in various locations within the pancreas, including the tail, head, and body. Patients may benefit from improved quality of life by avoiding unnecessary surgeries.

Epidermoid Cyst in an Intrapancreatic Accessory Spleen Complicating Clinical Decision-Making: A Case Report With Characteristic Imaging Findings

Epidermoid cyst in intrapancreatic accessory spleen (ECIPAS) is a rare benign condition that occasionally mimic malignant pancreatic neoplasms. We present a case of ECIPAS in a 53-year-old asymptomatic male, initially discovered incidentally during imaging for a suspected hepatic hemangioma. The lesion, located in the pancreatic tail, demonstrated characteristic imaging features on contrast-enhanced computed tomography and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI), including a cystic component with peripheral solid tissue exhibiting splenic enhancement patterns. Despite these typical ECIPAS findings, the lesion increased in size from 38 × 33 mm to 50 × 45 mm over 12 months, accompanied by a significant rise in serum carbohydrate antigen 19-9 (CA19-9) from 21 to 330 U/mL. This clinical progression raised concerns about potential malignancy, leading to a robot-assisted spleen-preserving distal pancreatectomy. Histopathological examination confirmed the diagnosis of ECIPAS. Postoperatively, the patient's serum CA19-9 levels normalized. This case highlights that ECIPAS can complicate clinical decision-making through size increase and CA19-9 elevation, complicating preoperative diagnosis. However, careful analysis of imaging characteristics, particularly on SPIO-enhanced MRI, can aid in accurate diagnosis.

Ectopic lesions in the abdomen and pelvis: a multimodality pictorial review

Various ectopic lesions occur in the abdomen and pelvis and affect multiple organs including liver, gallbladder, pancreas, spleen, and organs of the genitourinary system. Ectopic organs may be present outside their normal positions, or ectopic tissues may develop while the original organ exists in its normal position. Both benign and malignant lesions can occur in ectopic organs and tissues. Owing to their unusual location, they can often be misdiagnosed as other lesions or even malignant lesions, such as metastasis or seeding. This multimodality pictorial review provides various cases of ectopic lesions in the abdomen and pelvis, which will help narrow the differential diagnosis and guide clinical decision-making.

Intrapancreatic accessory spleen with an epidermoid cyst: a malignant mimicry

With the liberal use of CT scan for clinical diagnosis, clinicians are faced with an increasing number of pancreatic incidentalomas. Compared with other incidentalomas, pancreatic incidentalomas have higher chances of future malignant transformation. There are many differential diagnoses, and epidermoid cyst in an intrapancreatic accessory spleen (ECIPAS) is extremely rare, with only a handful of reports. Preoperative diagnosis is often complicated, and the final diagnosis is usually only made after surgical resection.We report a 34-year-old man who had an incidentally noted 2.8 cm pancreatic tail cystic lesion on a CT scan done for urinary symptoms. The lesion had a solid nodular component that was worrisome for malignancy, and the patient underwent further evaluation with an MRI scan and endoscopic ultrasound of the pancreas. The differential diagnoses of cystic degeneration of neuroendocrine tumour, branch-duct intraductal papillary mucinous neoplasm with worrisome features or ectopic intrapancreatic spleen were made. A multidisciplinary tumour board recommended surgical resection given risk features of malignancy. The patient subsequently underwent a laparoscopic distal pancreatectomy with splenectomy, and histology confirmed the diagnosis of ECIPAS.Imaging characteristics of ECIPAS are non-specific, and most patients have a diagnosis made only after surgery. Therefore, more evidence is warranted for accurate preoperative imaging diagnosis to avoid unnecessary pancreatic surgery, which is not without its risks.

Epidermoid cyst within an intrapancreatic accessory spleen exhibiting abrupt changes in serum carbohydrate antigen 19-9 level: a case report

Background

Epidermoid cyst within an intrapancreatic accessory spleen (ECIAS) is a rare disease. While the detection of solid components relevant to an accessory spleen is a key diagnostic finding, the differential diagnosis between ECIAS and malignant tumors is difficult without resection in patients with no other findings of an accessory spleen.

Case presentation

A 73-year-old male was found to have an elevated carbohydrate antigen (CA) 19-9 level (95 U/mL) at an annual checkup, and a cystic lesion in the pancreatic tail was located by abdominal ultrasound. Abdominal magnetic resonance imaging (MRI) revealed a multicystic mass, 24 mm in diameter, which exhibited varying intensities on T2-weighted images. There were no findings suggesting solid components on contrast-enhanced computed tomography and magnetic resonance imaging. Re-evaluation of serum CA 19-9 level revealed a rapid increase to 901 U/mL, which declined to 213 U/mL 3 weeks later. Ruling out the lesion’s malignant potential was difficult, and the patient underwent distal pancreatectomy with splenectomy. Histological findings revealed an ECIAS including multiple cysts, with the mucinous component of each cyst exhibiting different stages of biological reaction; one ruptured cyst exhibited inflammatory changes.

Conclusions

Careful observation for changes in serum CA 19-9 level and MRI findings might facilitate the diagnosis of ECIAS without a solid component by imaging studies.

Malignant Transformation of an Epidermoid Cyst in an Intrapancreatic Accessory Spleen: A Case Report

A 33-year-old man was evaluated because of an incidentally found cyst in the pancreatic tail, which was first seen 6 years ago. The cyst was a unilocular cystic mass, 13.0 cm in diameter, and had increased in size in last 2 months. On F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), the cystic wall showed increased FDG uptake. The patient underwent distal pancreatectomy with suspicion of mucinous cystic neoplasm of the pancreas. The mass turned out to be a squamous carcinoma arising from an epidermoid cyst in an intrapancreatic accessory spleen (ECIPAS). FDG PET/CT may assist recognition of a potential malignant lesion arising from an ECIPAS.

Superparamagnetic iron-oxide-enhanced diffusion-weighted magnetic resonance imaging for the diagnosis of intrapancreatic accessory spleen

PURPOSE

To evaluate the diagnostic performance of superparamagnetic iron-oxide (SPIO)-enhanced diffusion-weighted image (DWI) for distinguishing an intrapancreatic accessory spleen from pancreatic tumors.

MATERIALS AND METHODS

Twenty-six cases of intrapancreatic accessory spleen and nine cases of pancreatic tail tumors [neuroendocrine tumor (n = 8) and pancreatic adenocarcinoma (n = 1)] were analyzed. Two blind reviewers retrospectively reviewed the SPIO-enhanced magnetic resonance imaging (MRI) scans. The lesion visibility grades were compared and the diagnostic performance of SPIO-enhanced DWI was compared to those of SPIO-enhanced T2WI and T2*WI with the use of a receiver operating characteristic (ROC) analysis.

RESULTS

The grade of lesion visibility was the highest on DWI [mean ± standard deviation (SD): 2.8 ± 0.3] followed by T2WI (2.3 ± 0.7, p < 0.001) and T2*WI (2.1 ± 0.7, p < 0.0001). Reviewers 1 and 2 correctly characterized the presence or absence of SPIO uptake in 34 of 35 cases (97.1%) on DWI, 24 (68.6%) and 25 (71.4%) cases on T2WI, respectively, and 16 (45.7%) and 17 (48.6%) cases on T2*WI. The area under the ROC curve (AUC) of DWI was 0.974 and 0.989 for reviewers 1 and 2, respectively. For Reviewer 1, the AUC of DWI was significantly higher than that of T2*WI (0.756, p < 0.01), although it was not significantly different from that of T2WI (0.868, p = 0.0857). For Reviewer 2, the AUC of DWI was significantly higher than those of T2WI (0.846, p < 0.05) and T2*WI (0.803, p < 0.01).

CONCLUSION

The diagnostic performance of SPIO-enhanced DWI was better than those of SPIO-enhanced T2*WI and T2WI for the diagnosis of intrapancreatic accessory spleen.

Epidermoid cyst in intrapancreatic accessory spleen: A systematic review

BACKGROUND/OBJECTIVES

Due to its rarity, epidermoid cyst in intrapancreatic accessory spleen (ECIPAS) is still a diagnostic dilemma during clinical practice. The aim of this review was to summarize the epidemiologic features and management of ECIPAS.

METHODS

MEDLINE and EMBASE were searched for English articles reporting on ECIPAS up to April 30th, 2018 following the methodology suggested by the PRISMA guidelines. Categorical variables were reported as frequency and percentage. Continuous variables were reported as median (range).

RESULTS

A total of 56 patients from 47 full articles were included for the final data synthesis. More than half of the ECIPASs (59%) were found incidentally. The female/male ratio was 1.33. ECIPAS is typically a single mono-/multi-lobular cystic lesions in the pancreatic tail with thickened cystic wall or various amount of solid component which had identical density/signal to the spleen on imaging examinations. The cyst is filled with serous or non-serous fluid. Recognition of the surrounding ectopic splenic tissue is the key point to diagnose ECIPAS. However, no preoperative examination was able to make a definite diagnosis. Almost all the patients (96%) received surgical treatment, due to the suspicion of pancreatic malignant or potentially malignant cystic tumor, especially mucinous cystic neoplasm (MCN).

CONCLUSIONS

Although seldom encountered, ECIPAS should be considered as a differential diagnosis for pancreatic cystic lesions, especially when solid component was detected. As a benign disease, unnecessary surgery should be avoided. Because it is difficult to make a definite diagnosis preoperatively by one single examination, multiple modalities may be required.

Laparoscopic spleen-preserving pancreatic resection for epidermoid cyst in an intrapancreatic accessory spleen: case report and literature review

Introduction

An epidermoid cyst in an intrapancreatic accessory spleen (ECIPAS) is a rare non-neoplastic cyst, typically occurring in the pancreatic tail. It is difficult to preoperatively differentiate ECIPAS from other types of pancreatic neoplastic cysts.

Case presentation

We herein report a case of a 32-year-old man with a cystic tumor in the tail of the pancreas. The patient underwent a laparoscopic spleen-preserving distal pancreatectomy, and histological examination revealed the presence of ECIPAS. In addition, we also performed a literature review of 42 case reports of ECIPAS.

Conclusion

Although the preoperative diagnosis of ECIPAS is relatively difficult, familiarity with the imaging features, the clinical presentation and the location of the cyst could lead to a correct preoperative diagnosis of ECIPAS, which might thereby reduce the number of unnecessary resections.

Benign Tumors and Tumorlike Lesions of the Pancreas

The pancreas is a complex organ that may give rise to large number of neoplasms and non-neoplastic lesions. This article focuses on benign neoplasms, such as serous neoplasms, and tumorlike (pseudotumoral) lesions that may be mistaken for neoplasm not only by clinicians and radiologists, but also by pathologists. The family of pancreatic pseudotumors, by a loosely defined conception of that term, includes a variety of lesions including heterotopia, hamartoma, and lipomatous pseudohypertrophy. Autoimmune pancreatitis and paraduodenal ("groove") pancreatitis may also lead to pseudotumor formation. Knowledge of these entities will help in making an accurate diagnosis.

Epidermoid Cyst in an Intrapancreatic Accessory Spleen: Case Report and Literature Review of the Preoperative Imaging Findings

An epidermoid cyst arising within an intrapancreatic accessory spleen (ECIAS) is rare, and also difficult to correctly diagnose before surgery. It is mostly misdiagnosed as a cystic tumor, such as a mucinous cystic neoplasm or as a solid tumor with cystic degeneration, such as a neuro endocrine tumor. We herein report a case of ECIAS and also perform a literature review of 35 reports of ECIAS. Although the preoperative diagnosis of ECIAS using conventional imaging is relatively difficult to make, careful preoperative examinations of the features on computed tomography and magnetic resonance imaging could lead to a correct preoperative diagnosis of ECIAS which might thereby reduce the number of unnecessary resections.

A rapidly growing epidermoid cyst in an intrapancreatic accessory spleen treated by laparoscopic spleen-preserving distal pancreatectomy: Report of a case

Epidermoid cysts arising in an intrapancreatic accessory spleen are exceedingly rare, furthermore the natural course of them is hardly known. We report a case correctly diagnosed with epidermoid cyst in an intrapancreatic accessory spleen, followed by 1 year observation, finally underwent surgical treatment. The patient presented with diarrhea. Contrast-enhanced computed tomography (CT) revealed a pancreatic cyst 20 mm in diameter, surrounded by a solid component showing the same enhancement as the spleen, suggesting the presence of an epidermoid cyst in an intrapancreatic accessory spleen. One year later, back discomfort developed, and a CT scan revealed that the cyst had grown to 38 mm in diameter. To obtain a definitive diagnosis, we performed a laparoscopic spleen-preserving distal pancreatectomy. The histopathological diagnosis was compatible with an epidermoid cyst in an intrapancreatic accessory spleen, which is benign. The postoperative course was uneventful. This case demonstrates that an epidermoid cyst arising in an intrapancreatic accessory spleen can rapidly grow, even if it is benign. Laparoscopic spleen-preserving distal pancreatectomy can be a useful procedure, with the advantages of low invasiveness and organ preservation, for the treatment of benign or low-grade malignant tumors located in the pancreatic body or tail.

Squamous-lined cyst of the pancreas: Radiological-pathological correlation

Pancreatic cystic lesions are increasingly being detected incidentally because of the increased use of cross-sectional imaging. Squamous-lined cysts of the pancreas (lymphoepithelial cyst, epidermoid cyst, and dermoid cyst) are rare cystic lesions lined with squamous epithelium. Distinguishing squamous-lined cysts from other cystic lesions of the pancreas is important to avoid unnecessary surgery, because squamous-lined cysts of the pancreas have no malignant potential. The purpose of this review is to describe findings on computed tomography and magnetic resonance imaging and the histopathological characteristics of squamous-lined cysts, and to summarize the key points of differential diagnosis for pancreatic cystic lesions.

Epidermoid cyst of an intrapancreatic accessory spleen: a case report and literature review

Background

An epidermoid cyst in an intrapancreatic accessory spleen is a rare lesion. Despite advances in radiologic techniques, in most cases it has been diagnosed preoperatively as a possible pancreatic neoplasm.

Case presentation

Herein, we present a 63-year-old Caucasian woman, diagnosed preoperatively with enhanced-contrast abdominal computed tomography, as having a potential cystic tumor in the tail of the pancreas. The patient underwent a distal pancreatectomy and splenectomy, and the histological examination revealed the presence of an epidermoid cyst of an accessory intrapancreatic spleen.

Conclusions

Familiarity with the imaging features, the clinical presentation and the location of the cyst are important to consider if this rare entity is to be included in the differential diagnosis of cystic neoplasms of the pancreas.

Epidermoid cyst of the spleen

BACKGROUND

The aim of this study is to elucidate the characteristics, clinical presentations, and management of epidermoid cysts located in the spleen and the intrapancreatic accessory spleen.

METHODS

Data pooled for analysis were collected from epidermoid cyst cases encountered in the study institution and sporadic case reports obtained from the English literature.

RESULTS

There were 115 cases of epidermoid cyst. Seventy eight (67.8 %) were found in the spleen, whereas 37 (32.2 %) were found in the intrapancreatic accessory spleen. Comparing between the two groups, the splenic group showed female predominance, younger age, and larger cystic size. For symptoms, left upper abdominal mass (57.7 %) and left upper abdominal pain (39.0 %) were more commonly found in the spleen group. Meanwhile, the intrapancreatic accessory spleen group had higher percentage of asymptomatic cysts (59.5 %). As for surgical indication, majority of patients in the spleen group underwent surgery for symptomatic relief (75.4 %), while the intrapancreatic accessory spleen group underwent surgery mainly for suspicious malignancy (90.0 %).

CONCLUSIONS

Surgical treatment for epidermoid cysts of the spleen is considered the optimal treatment for either alleviating the symptoms caused by a bulky cyst or for determining the histopathologic nature of a suspicious malignant cystic neoplasm.

Laparoscopic resection of an epidermoid cyst within an intrapancreatic accessory spleen: a case report and review article

CASE REPORT

We report a case of an epidermoid cyst within an intrapancreatic accessory spleen that was treated by laparoscopic excision. A 39-year-old man with no abdominal symptoms was incidentally found to have a cystic pancreatic lesion on computed tomography scan undertaken for suspected deep vein thrombosis. Further computed tomography and magnetic resonance imaging confirmed similar findings and the laparoscopic resection of the distal pancreas and spleen was undertaken as malignancy could not be excluded. Microscopic analysis revealed a well-circumscribed epidermoid cyst within a thin splenic rim in the tail of the pancreas.

DISCUSSION

Such histologic diagnoses are extremely rare, and this is the 26th case report to our knowledge in English language journals. These lesions should be treated surgically to exclude malignancy. This is the first case reported in the United Kingdom and the first to be excised by pure laparoscopic means, which we believe provides effective and successful surgical management.

Intrapancreatic accessory spleen: CT appearance and differential diagnosis

Although autopsy studies report that the second most common site of the accessory spleen is in the tail of the pancreas, intrapancreatic accessory spleens (IPASs) are rarely recognized radiologically. With recent improvements in imaging techniques, IPASs are more commonly detected on imaging studies. IPAS can be mistaken for other type of mass-forming lesions in the tail of the pancreas, particularly an asymptomatic small neuroendocrine neoplasm. Rarely, an epidermoid cyst originating from IPAS may simulate other cystic pancreatic lesion. Accurate preoperative diagnosis would obviate unnecessary surgery. IPAS should be considered when a hypervascular mass is seen in the tail of the pancreas on CT. Typical location, similar attenuation of the lesion to the spleen on noncontrast, and postcontrast CT at different phases are helpful to make diagnosis of IPAS. In particular, characteristic heterogeneous contrast enhancement of IPAS on the arterial phase may be helpful for correct diagnosis. However, when it remains difficult to exclude the other diagnosis, (99m)Tc labeled heat-damaged red blood cell scintigraphy or superparamagnetic iron oxide-enhanced MRI can be used to confirm the diagnosis of IPAS.

Epidermoid cyst in intrapancreatic accessory spleen: computed tomography findings and clinical manifestation

OBJECTIVE

This study aims to assess retrospectively the imaging features of computed tomography (CT) and clinical characteristics of epidermoid cyst in intrapancreatic accessory spleen (ECIPAS).

METHODS

Seven consecutive patients with pathologically confirmed ECIPAS were included. CT images and clinical data were analyzed. The CT features emphasized included the location, size, calcification, cystic features, surrounding accessory spleen, density, and enhancement of the lesions.

RESULTS

Five patients were male and two were female with a mean age of 43.2 years ranging from 25 to 66 years. Most cases were incidentally detected. All lesions were situated in the pancreatic tail, wherein the mean size was 4.4 cm. The cyst appeared unilocular in four cases and multilocular in three cases. An accessory spleen surrounding the cyst was recognized in all seven cases, and the cystic wall of ECIPAS showed a contrast enhancement similar to that of the spleen during multiphasic scans.

CONCLUSION

ECIPAS is an extremely rare entity. The diagnosis of an ECIPAS should be considered when enhancing the cystic wall of the lesion in the pancreatic tail similar to that of the spleen during multiphasic scans.

Intrapancreatic accessory spleen: clinicopathologic analysis of 12 cases

OBJECTIVES

Intrapancreatic accessory spleen is a benign lesion that mimics hypervascular or cystic pancreatic neoplasm. A comprehensive clinicopathologic analysis has not yet been reported.

METHODS

We described the clinicopathologic characteristics of 12 cases of pathologically proven intrapancreatic accessory spleen, among which 6 had internal epidermoid cysts. Immunohistochemistry was done to clarify the origin of epidermoid cysts.

RESULTS

Most cases were incidentally detected in young adults. Two-thirds of cases with intra-lesional cysts showed elevated serum carbohydrate antigen 19-9 levels. Radiologically, heterogeneously enhancing a solid portion similar to the spleen was a helpful, but not convincing, feature. Grossly, a well-circumscribed dark red mass with or without cysts in the pancreatic tail was characteristic. Microscopically, small foci of pancreatic tissue were embedded within the splenic tissue. Epidermoid cysts consisted of modified squamous epithelium, some of which had intracellular mucin. Cytologic smears showed large aggregates of benign spindle cells that were reactive against CD8. Immunohistochemical staining of the cystic epithelium suggested its pancreatic ductal origin.

CONCLUSIONS

Intrapancreatic accessory spleen with or without epidermoid cyst should be considered as differential diagnoses when well-enhanced solid or cystic tumors are found in the pancreatic tail. Radiologic suspicion and preoperative aspiration or biopsy might minimize the need for unnecessary surgery.

Pancreatic Cystic Lesions of Nonmucinous Type

Cystic lesions of nonmucinous type can arise within the pancreas or can develop from adjacent structures and appear to involve the pancreas. In addition, some typically solid masses can become cystic or can present as cystic lesions. Nonmucinous cysts can be neoplastic, inflammatory, reactive, or congenital. The vast majority of neoplastic nonmucinous cysts are benign. Because of the difficulty in determining the neoplastic potential of a pancreatic cyst preoperatively, many non-neoplastic cysts are resected. This article reviews the surgical pathology of nonmucinous cysts.