Case Of Intrapancreatic Accessory Spleen Research Articles

Intrapancreatic accessory spleens in African swine fever infection of wild boar (Sus scrofa).

Intrapancreatic accessory spleen (IPAS) is one of the most frequent congenital splenic anomalies in humans; however, studies in veterinary medicine are scarce. This study aimed to describe the macroscopic, histopathological and immunohistochemical features of 11 suspected cases of IPAS in wild boar piglets of 3-4 months old. Seven of the 11 animals were immunised with a low virulence isolate of African swine fever virus (ASFV) and subsequently challenged with a highly virulent ASFV isolate (LVI-HVI group). The remaining four animals were exclusively infected with a highly virulent isolate of ASFV (HVI group). Grossly, lesions comprised focal or multifocal reddish areas of variable shape, located on the surface of the pancreatic tail or within the parenchyma. Histological and immunohistochemical studies (anti-CD79 and CD3) confirmed the presence of IPAS in eight of the 11 cases. IPAS shared the same histological structure and alterations as those observed in the original spleen. The immunohistochemical study against ASFV revealed the presence of VP72+ cells in both the spleen and IPAS of seven of the eight piglets. The results of this study describe for the first time the presence of IPAS in ASFV infection of wild boar (Sus scrofa) regardless the isolate and suggest that the infection may induce the development of ectopic splenic tissue due to an increased demand for phagocytic cells from the reticuloendothelial system. However, further studies are needed to understand the immunological mechanisms that trigger the formation of these accessory organs.

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

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

EUS/İİA Sitolojisi ile Tanı Almış İntrapankreatik Aksesuar Dalak: Zihin Ancak Kavramaya Hazır Olduğunu Algılayabilir

Intrapancreatic accessory spleen is a relatively uncommon congenital lesion, with a prevalence of 2%; reported in an autopsy series. Radiological differential diagnosis for intra and peripancreatic accessory spleen includes pancreatic neuroendocrine tumors, lymphoepithelial cysts, lymphomas, hypervascular metastases, solid pseudopapillary tumors and pancreatic adenocarcinomas. Accessory spleen is a clinically quiescent entity which is usually asymptomatic. It does not require surgical resection or extra follow up. In a patient with an intra-peripancreatic mass, in order to prevent invasive procedures such as unnecessary surgical resections and to decrease patient morbidity and mortality rates, the endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytological diagnosis is mandatory. As this is a very rare entity in routine practice, the cytopathologists should keep it in mind, in the differential diagnoses of a pancreatic mass. In this report, we present a rare case of intrapancreatic accessory spleen which is diagnosed by EUS /FNA cytology, discussing its unique cytomorphological and immunohistochemical characteristics.

Pancreatic Incidentaloma: Differentiating Nonfunctioning Pancreatic Neuroendocrine Tumors from Intrapancreatic Accessory Spleen

To improve the preoperative assessment of pancreatic incidentalomas (PIs) by analysis of 1 index case and characterization of the published features of intrapancreatic accessory spleen (IPAS) compared to pancreatic neuroendocrine tumor (PNET). A search of the literature using the online database MEDLINE. In all, 46 cases of IPAS have been described to date: 17 were "presumed" as IPAS based on technetium-99m (Tc-99m) scanning, fine-needle aspiration (FNA) stain for CD8, or contrast-enhanced sonography; 29 were misdiagnosed as PNET and underwent surgery. The pancreatic lesions were 1) mostly solitary; 2) solid on imaging; 3) well defined; 4) located predominantly at the pancreatic tail; 5) not exceeding 3 cm in the largest diameter; 5) all detected in adults (22-81 years); 6) not related to sex. In subjects referred for surgery, standard imaging studies/imaging protocols did not differentiate between IPAS and PNET. FNA was performed in 5/46 cases, all of which were false-positive for PNET. Immunohistochemical staining for T-cells on FNA material and specific imaging features (characteristic arciform splenic enhancement pattern on dynamic computed tomography [CT]; nuclear scintigraphies with radioisotope specifically trapped by splenic tissue [Tc-99m]) or contrast-enhanced sonography offered valuable clues. Still, distal pancreatectomy and splenectomy was carried out in 72%, and the rest had distal pancreatectomies. IPAS should be considered before surgery in patients with PIs. A new practical algorithm is presented for better preoperative evaluation of such lesions; it combines the recognition of early indicators and sequential consideration of cytologic and imaging features to decrease the hazards of unnecessary major surgery. CT = computed tomography EUS = endoscopic ultrasound FNA = fine-needle aspiration HDRBC = heat-damaged red blood cells IPAS = intrapancreatic accessory spleen MRI = magnetic resonance tomography NF-PNET = nonfunctioning pancreatic neuroendocrine tumor PET = positron emission tomography PNET = pancreatic neuroendocrine tumor PI = pancreatic incidentalomas SPIO = superparamagnetic iron oxide Tc-99m = technetium-99m.

Endoscopic Ultrasound-Guided, Needle-Based Probe Confocal Laser Endomicroscopy (nCLE) of Intrapancreatic Accessory Spleen: Case Report and Literature Review

Introduction: Accessory spleens are often incidental findings on imaging and usually present as a solid mass at splenic hilum or other organs such as pancreas. Most patients with accessory spleens are asymptomatic however abdominal pain has been associated with an accessory spleen. Intrapancreatic accessory spleen (IPAS) can mimic a pancreatic neuroendocrine tumor (NET) on imaging studies and therefore posing a diagnostic dilemma. We present a case of IPAS in which the concomitant use of nCLE and fine needle aspiration (FNA) helped make the diagnosis. A 24 year old female referred for EUS for a pancreatic mass on CT scan. She presented with abdominal pain and during the workup a 3cm x 2.9cm round hypervascular hypodense mass in the tail of the pancreas was found. Her past medical history is significant for second degree relative with pancreatic cancer. Patient has a past medical history of Thrombotic Thrombocytopenic Purpura (TTP) and she underwent splenectomy 5 years ago for profound thrombocytopenia. On EUS a 2.8cm x 2.9cm round homogenous hypoechoic mass in pancreatic tail was identified. Initially the mass was punctured using a 19-G needle that was pre-loaded with AQ-Flex 19 probe inside the needle before puncture in lieu of the stylet. Fluorescein (2.5mL of 10 % fluorescein sodium) was injected simultaneously with probe insertion. Numerous thick white bands with floating small black particles inside the bands suggestive of network of blood vessels and floating Erythrocytes. Interrogation of the mass did not identify any finger-like papillary projections, crypt-like structures or dark aggregates of cells which is seen in a villous structure or neoplastic cells. Then 4 passes using a 22 G FNA needle was performed with onsite pathology and endomicroscopy review supported the final diagnosis of IPAS. Discussion: Accessory spleen is a rare entity which can be seen in the splenic hilum or at the tail of the pancreas. In 3000 autopsies reported by Halpert et al, 364 accessory spleens were found in which 17% were IPAS. Accessory spleens can be acquired entities (splenosis) which is the auto transplantation of splenic tissue in abnormal locations as a result of trauma or post splenectomy. This is the first case that incorporates real-time endomicroscopy and onsite pathology to diagnose IPAS. Patients with IPAS may undergo distal pancreatectomy because they mimic a hypervascular NET on CT and MRI scans. Onsite pathology and endomicroscopy review increases the diagnostic accuracy for differentiating between IPAS and pancreatic NET. In patients with a hypervascular mass in the tail of pancreas addition of real time nCLE to traditional FNA can increase the diagnosis yield of EUS and potentially prevent unnecessary surgery.Figure 1Figure 2Figure 3

Radiologic findings of intrapancreatic accessory spleen

Introduction: Accessory spleen is an anomaly that observed in about 10% of individuals by the autopsy study,and the most of the accessory spleens are located close to the splenic hilum. Although the accessory spleen is a frequently encountered entity, intrapancreatic accessory spleen (IPAS) is rarely recognized radiologically and which is sometimes misdiagnosed pancreatic neoplasms. We present a case of IPAS which radiologically mimicking a pancreatic tumor in the tail of the pancreas. Case report: A 45 year-old man who presented with abdominal pain scanned with abdominal US, CT and MRI. On US a well defined hypoechoic mass, measuring 10x12 mm in diameter that was located in the tail of the pancreas. Enhanced CT showed a well-defined and homogeneously enhanced tumor, about 10 mm in size in the tail of the pancreas. A well-defined 10 mm,solid, enhancing mass was identified on MR images, and for all sequences, was of similar signal intensity as that of the spleen. Discussion: Accessory spleen is a congenital abnormality consisting of normal splenic tissue in ectopic sites. They are found most commonly near the splenic hilum. One in every six accessory spleens is located in the tail of the pancreas. The diagnosis of an IPAS should be considered when a pancreatic mass has the CT densities and/or MRI signal intensities similar to those of the spleen, with and without contrast medium.

EUS-FNAで確定診断し得た膵内副脾の1例

EUS-FNAで確定診断し得た膵内副脾の1例

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.

A Case of Intrapancreatic Accessory Spleen Mistaken as a Pancreatic Mass due to Different Enhancing Pattern from Normal Spleen

Most cases of accessory spleen show similar features as normal spleen in imaging studies. However, some accessory spleen has unusual scan feature which can be misdiagnosed. We present a case of intrapancreatic accessory spleen that was discovered incidentally during a workup for abdominal pain in a 47-year-old woman. CT and MRI revealed a different enhancing pattern from that of the spleen. Further evaluation with endoscopic ultrasonography failed to identify the pancreatic mass. Therefore, it was surgically removed and diagnosed pathologically as an accessory spleen.

Intrapancreatic Accessory Spleen Diagnosed on Radionuclide Imaging

Intrapancreatic accessory spleen (IPAS) is ectopic splenic tissue distinct from the main spleen. A 46-year-old man with chronic hepatitis C, presented in 2006 with low right chest pain which led to a diagnosis of tuberculosis pleurisy. CT scan and MRI showed a round, homogenous, well limited mass of 3cm in the pancreas tail. Tc-99m heat-damaged red blood cell scintigraphy with SPECT-CT was performed to confirm the diagnosis of IPAS. Most cases of IPAS described in the literature were diagnosed by pathologists after distal pancreatectomy and splenectomy performed for a suspicion of pancreatic tumor. However, heat-damaged red blood cell scintigraphy remains the most commonly used diagnostic procedure for IPAS, even if superparamagnetic iron oxide MRI contrast agent may be used in the future.

Imaging features of intrapancreatic accessory spleen

Although accessory spleens are commonly identified on CT, intrapancreatic accessory spleen (IPAS) is often not recognised or is mistaken for other pancreatic lesions. Currently, with improved cross-sectional techniques and spatial resolution, IPAS is more detectable. We report the imaging features and work-up for the differentiation between IPAS and other pancreatic lesions. An index case of a suspected pancreatic tail islet cell tumour, subsequently confirmed as IPAS, led to inquiries into the incidence of IPAS and the means of preventing unnecessary surgery. For 2 years, we searched for IPAS during our daily interpretations and compared these cases with those taken from our institution's database to determine the distinguishing characteristics. Three proven cases of IPAS, which mimicked pancreatic tail lesions on CT, are presented. Nine patients with suspected IPAS, based on imaging characteristics and stability, are also described. All cases of IPAS are well defined, 1-3 cm in size, follow the density and intensity of the spleen on CT and MRI, and accumulate technetium-99m ((99)Tc(m)) sulphur colloid and (99)Tc(m) heat damaged red blood cell scintigraphy (in contrast to other lesions). In conclusion, radiologists should be aware that a subtle pancreatic tail lesion could be an IPAS. A high index of suspicion will lead to correlative imaging. A combination of CT, MRI and nuclear medicine examinations can confirm the diagnosis and prevent unnecessary surgery.

Intrapancreatic accessory spleen: A case report and review of the literature

Here, we report a case of intrapancreatic accessory spleen confirmed by pathologic diagnosis and discuss its differential diagnosis and surgical management with a review of the literature.

Intrapancreatic accessory spleen: Mimic of pancreatic endocrine tumor diagnosed by endoscopic ultrasound‐guided fine‐needle aspiration biopsy

Intrapancreatic accessory spleen forms a well-defined nodule within the tail of the pancreas and is commonly mistaken by imaging studies as a neuroendocrine tumor. We report three cases of intrapancreatic accessory spleen diagnosed by endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) biopsy. Imaging studies showed well-circumscribed nodules in the tail of the pancreas. Two lesions were clinically suspicious for pancreatic neuroendocrine tumors and one appeared to be a cyst. EUS-guided FNA revealed predominantly small lymphocytes with a subset of histiocytes, conspicuous eosinophils, and plasma cells. There was also characteristic CD8 positive immunostaining of endothelial cells in cell block sections. We report the first series of accessory spleen in the pancreas diagnosed by EUS-guided FNA with the aid of CD8 immunostaining of splenic sinus endothelial cells.

Intrapancreatic Accessory Spleen Mimicking Endocrine Tumor of the Pancreas: Case Report and Review of the Literature

Accessory spleen is an anomaly that is observed in about 10% of individuals by the autopsy study, and most accessory spleens are located close to the splenic hilum. Although accessory spleen is a frequently encountered entity, intrapancreatic accessory spleen (IPAS) is rarely recognized radiologically and is sometimes mistaken for another type of pancreatic neoplasm. Only 10 IPAS cases surgically resected as solid pancreatic mass have been reported in the English literature. We herein report a case of IPAS mimicking an endocrine tumor of the pancreas and review of the literature.

Accessory spleen presenting as a mass in the tail of the pancreas

In this case report, we describe an accessory spleen that presented as a mass in the tail of the pancreas and mimicked a neoplasm. Intrapancreatic accessory spleen have a relatively high prevalence and can be mistaken for tumors. We present a case of intrapancreatic accessory spleen in a 40-year-old man, which was discovered incidentally during a workup for an aortic dissection. Computerized axial tomography and magnetic resonance imaging scans demonstrated a hypervascular mass in the tail of the pancreas. The clinical and radiological differential diagnosis included pancreatic mucinous cystic neoplasm, pancreatic endocrine neoplasm, solid pseudopapillary tumor, ductal adenocarcinoma, and metastasis. After a distal pancreatectomy was completed, microscopic examination revealed heterotopic splenic tissue.

Intrapankreatische Nebenmilz als Differentialdiagnose des Pankreasschwanzkarzinomes

According to autoptic studies, accessory spleens may be found in 10-15% of the population and most of them are usually located at or near the splenic hilum. Only in 1-2% they are located in the pancreatic tail. We report a rare case of intrapancreatic accessory spleen which radiologically mimicked a tumor in the tail of the pancreas. A 54-year-old man was diagnosed with a tumor at the pancreatic tail. In the preoperative computed tomography (CT), there was a lesion (2.6 cm in diameter) in the pancreatic tail and two locoregional lesions (1 and 1.5 cm in diameter), which had intensive contrast enhancement. The diagnosis of a nonfunctioning endocrine pancreatic tail carcinoma with lymph node metastasis was made. Intraoperative examination showed two accessory spleens nearby the pancreatic tail. As pancreatic cancer could not be excluded because of the local findings, an oncological left pancreatectomy was performed. Histological examination excluded cancer and revealed an intrapancreatic accessory spleen and two accessory spleens nearby the pancreatic tail. Intrapancreatic accessory spleen should be included in the differential diagnosis of pancreatic neoplasm.

Intrapancreatic accessory spleen: evaluation by CT arteriography.

Intrapancreatic accessory spleens are frequently confused with primary pancreatic tumors, and differentiation from neoplastic lesions is important to avoid an unnecessary laparotomy. We present three cases of intrapancreatic accessory spleen evaluated by computed tomographic arteriography (CTA) and discuss the characteristic findings. CTA was performed, followed by digital subtraction angiography, with an injection of contrast material through a 4-F catheter placed in the celiac artery. Single-level dynamic CTA was also performed in two patients with a 30-s continuous scan in one breath-hold. CTA clearly demonstrated early inhomogeneous enhancement of the lesion, similar to the splenic parenchyma. On single-level dynamic CTA, inhomogeneous enhancement of the lesion in the early phase was diminished in the late phase. Multiplanar reformatted images obtained in two cases showed the deep cleft between the lesion and the pancreas, which suggested that the lesion was originally extrapancreatic. These two findings on CTA, inhomogeneous enhancement of the lesion and the deep cleft between the lesion and the pancreas, may help to confirm the diagnosis of an intrapancreatic accessory spleen.