Mucinous Cystadenoma: Pitfalls of Differential Diagnosis

Cystic neoplasms of the pancreas often are difficult to differentiate from pseudocysts. It has been proposed that a history of clinical pancreatitis, elevated serum pancreatic enzymes, elevated cyst fluid amylase, and a communication with the pancreatic duct suggest the diagnosis of a pseudocyst. We report the case of a young woman who presented with a cystic mass in the pancreas and was thought to have a pseudocyst because of the above; at surgery, a mucinous cystadenoma was documented. The pitfalls of differentiating neoplastic cysts of the pancreas from pseudocysts are discussed.     

Cystic tumors of the pancreas

The discovery of a cystic lesion in the pancreas implies a challenge for the physician. Approximately 10% are cystic tumors, benign to highly malignant, or true cysts, showing all stages of cellular differentiation, from benign to highly malignant tumors. Malignant cystic tumors are rare and comprise only about 1% of all pancreatic malignancies, they are potentially curable. Therefore, correct diagnosis and treatment of these lesions are of great importance. It is usually not possible to separate a pseudocyst from a benign cyst or a cystic tumor, but there are some signs and findings that could be helpful in the clinical decision. The diagnosis of a cystic pancreatic tumor requires different imaging techniques, including ultrasonography, computerized tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography, but to distinguish a pseudocyst or a benign cyst from a potentially malignant lesion can be very difficult. The usefulness of blood tests and investigations of cyst fluid can be questionable. Today, surgical treatment of cystic pancreatic tumors can be performed with low morbidity. Therefore, we conclude that an active strategy with resection of cystic tumors of the pancreas should be recommended.     

Symptomatic pancreatic polypeptide-secreting tumor of the distal pancreas (PPoma)

Our report describes a 46-yr-old woman who presented with watery diarrhea in the presence of multiple endocrine neoplasia type I (MEN I) syndrome. Of various potential pancreatic endocrine hormones, only serum levels of pancreatic polypeptide were elevated. Radiologic imaging failed to identify a pancreatic tumor; her diarrhea was therefore managed with subcutaneous administration of somatostatin. Three years later she developed gallstone pancreatitis with the subsequent development of a pancreatic pseudocyst. At exploration for drainage of the pseudocyst, intraoperative ultrasound identified a 6-mm tumor in the distal pancreas that was resected. Final pathology documented a pancreatic endocrine tumor with immunohistochemical staining demonstrating the presence of pancreatic polypeptide. The present case illustrates the symptomatology that may be associated with pancreatic polypeptide-secreting endocrine tumors of the pancreas.     

A case of papillary tumor of the pancreas

The authors report a case of papillary cystic tumor which is a rare form of pancreatic tumor of exocrine origin. A young woman presenting with a painful abdominal mass was operated on for a tumor of the head of the pancreas. Gross and microscopic examination revealed a papillary cystic tumor of the pancreas. Tests for histologic markers found progesterone receptors. A review of the literature found approximately 100 cases of papillary cystic tumors of the pancreas. This type of tumor is seen mainly in young women presenting with an abdominal mass. After complete resection of the tumor, these patients usually make an uneventful recovery. Since regrowth of the tumor may occur these patients should be submitted to prolonged follow-up.     

Pancreatic cystic endocrine neoplasms

A rare case of cystic pancreatic endocrine tumor is presented, and the literature is reviewed. The patient was initially misdiagnosed as having a pancreatic pseudocyst, and that condition was managed accordingly. Persistence of the cystic lesion and reoperation led to the correct diagnosis and management. The neoplasm stained positive for glucagon and pancreatic polypeptide, but there were no clinical abnormalities that suggested hyperfunction. All cystic lesions of the pancreas should undergo biopsy at operation, to avoid an erroneous diagnosis of benign pseudocyst. Neoplastic lesions should be resected, not internally drained.     

Rare case of adult pancreatic hemangioma and review of the literature

Pancreatic hemangiomas are a rare type of cystic tumor, with very few cases reported in the literature. Herein, we present the case of a 28-year-old woman who was admitted to our hospital for abdominal pain. A physical examination failed to reveal any abnormalities that could explain her symptoms. A contrast-enhanced computed tomography showed a multilocular cyst with moderately enhanced septa and fluid-fluid levels in the body and tail of the pancreas. A serous cystadenoma or pseudocyst of the pancreas was initially suspected, and the patient underwent a subtotal pancreatectomy and splenectomy. The pathologic diagnosis was a pancreatic hemangioma. This is the second case of pancreatic hemangioma with fluid-fluid levels reported in the literature. Upon imaging, the presentation of this tumor can resemble serous or mucinous cystadenomas, pseudocysts of the pancreas, and side-branch type intraductal papillary mucinous neoplasms. This report reviews the clinical symptoms, radiologic features, pathologic characteristics, differential diagnoses, and treatment of this rare lesion type.     

A new case of congenital cyst of the pancreas

A new case of congenital cyst of the pancreas is reported. A 34-year-old woman was admitted with a painless, large, epigastric mass. Ultrasonography revealed an anechogenic retrogastric tumor. Computed tomography scan described a liquid cyst of the pancreas which was 15 cm in diameter. During surgery, a well-delimited translucent cyst was found and no local malignancy was observed. Extensive distal pancreatic resection with preservation of the spleen was performed and a thin part of cephalic pancreas was preserved. The liquid of the cyst did not contain any mucus. Microscopic study of the cyst wall described normal cuboidal cells and congenital cyst of the pancreas was diagnosed. Several diagnoses including hydatid cyst, pseudocyst and cystic tumors of the pancreas are discussed. Before surgery, lack of acute pancreatitis in recent medical history rules out pseudocyst and hydatid cyst. During the operation, if cystadenocarcinoma is easily ruled out, macrocystic serous cystadenoma is more difficult to exclude. Only histological examination of the cystic wall confirms the difference between cystadenoma and congenital cyst which remains an exceptional entity.     

Adrenal pseudocyst mimicking cystic neoplasm of pancreatic tail

Cystic neoplasms of the pancreatic tail are usually picked up as incidental findings during imaging studies. We report an unusual case of adrenal pseudocyst mimicking cystic tumor of pancreatic tail who presented with abdominal pain and weight loss. Ultrasonography and CT of the abdomen revealed a cystic mass in relation to the pancreatic tail. On exploration, a cystic mass was present in the tail of the pancreas, for which distal pancreatectomy was performed. The histopathology report surprisingly revealed an adrenal pseudocyst without a cellular lining. The normal adrenal gland was compressed in the wall. This case highlights that this rare possibility should be considered in the differential diagnosis of cystic lesions of the pancreatic tail.     

Intrapancreatic gastric duplication cyst mimicking pancreatic cystic tumor

Cystic lesions of the pancreas are sometimes difficult to diagnose. We report a case of a gastric duplication cyst (GDC) of the pancreas in an adult. A 45-year-old woman was admitted to our department for the investigation of anemia. Abdominal ultrasonography revealed a large cystic lesion, measuring about 40 × 70 mm with calcification in the tail of the pancreas. Contrast-enhanced computed tomography of the abdomen revealed a non-enhanced cystic lesion with non-enhanced wall. Endoscopic retrograde pancreatography revealed a mild extended main pancreatic duct and an aberrant pancreatic duct, but there was no communication with the cyst. We could not deny the malignancy, so distal pancreatectomy was performed. The pathological examination revealed that the inner wall of the cyst consisted of columnar epithelium and smooth muscle layer. Immunohistochemical analysis revealed the columnar epithelium to be immunopositive for cytokeratin 7 (CK7) and immunonegative for cytokeratin 20 (CK20) and the glands to be immunonegative for CK 7 and immunopositive for CK 20. Therefore, a diagnosis of GDC of the pancreas was made. On imaging, a GDC usually mimics a pancreatic pseudocyst or a cystic neoplasm of the pancreas. Therefore, even though it is rare, a GDC should be considered in the differential diagnosis of cystic tumors of the pancreas.     

Serous cystic neoplasms of the whole pancreas in a patient with von Hippel-Lindau disease

We describe here a case of von Hippel-Lindau (VHL) disease with a serous cystic neoplasm of the whole pancreas. The patient was a 35-year-old woman suffering from a palpable abdominal tumor. She had a history of hemangioblastomas of the cerebellum. CT revealed large solid tumors in the pancreatic head and body, and multiple cystic lesions in the whole pancreas as well as a right renal tumor. When endoscopic retrograde cholangiopancreatography (ERCP) was performed, bleeding from the duodenal papilla was detected. Since she had some distinguishing clinical features, the diagnosis of VHL disease was made. The preoperative diagnosis of the pancreatic lesion was serous cystic neoplasms with hemosuccus pancreaticus and total pancreatectomy was performed. Histological examination of the specimen revealed serous cystic neoplasms which occupied the entire pancreas. VHL cases operated on for serous cystic neoplasms of the entire pancreas are very rare.     

Mucinous cystic neoplasm of the pancreas during pregnancy: the importance of proper management

We describe a case of huge mucinous cystic tumor of the pancreas in a 26-year-old woman during pregnancy. Ultrasonography demonstrated a well-delimited cystic mass in the left upper abdominal quadrant, suggestive of benignity. Magnetic resonance imaging showed a large cystic mass resembling a mucinous cystic tumor of the pancreas. After this assessment the patient underwent surgical exploration and a huge cystic tumor of the pancreas was discovered. The tumor was enucleated and distal pancreatectomy was performed. The resected margin of the specimen was free of tumor. In this case report we discuss the management of mucinous pancreatic tumors during pregnancy and we briefly review the previously reported cases of mucinous pancreatic tumors in pregnant patients. We conclude that surgical resection of these tumors should be strongly considered in pregnancy. Removal of the tumor appears to be a safe procedure without harmful effects to the fetus.     

Large cystic acinar cell carcinoma of the pancreas

Acinar cell carcinoma of the pancreas is a rare neoplasm exhibiting pancreatic enzyme production by the neoplastic cells. It has a highly characteristic cellular arrangement reflecting its acinar derivation, and a definite diagnosis is made based on immunohistochemical and ultrastructural results. Such tumors are often large but rather well circumscribed. Some cases have a cystic appearance due to hemorrhage or necrosis, but a large cystic mass appearing as a pseudocyst is quite rare. We present a large cystic acinar cell carcinoma of the pancreas.     

不典型胰腺实性假乳头状瘤的影像学诊断及病理对照分析

目的分析不典型胰腺实性假乳头状瘤的影像学表现并与病理对照,探讨其诊断价值,就类似影像学表现的疾病进行鉴别诊断。方法选取77例胰腺实性假乳头状瘤患者,均行手术治疗,并经病理学和免疫组化分析。术前诊断为胰腺实性假乳头状瘤47例,胰腺囊肿7例,假性囊肿4例,胰腺脓肿5例,胰腺浆液性囊腺瘤7例,胰腺癌5例,胰腺血肿2例。对77例患者临床资料进行回顾性分析,比较其影像和病理学特点。结果 77例患者中男性29例,女性48例,年龄2~79岁,平均41.5岁。18例因触及上腹部包块就诊,12例有腹胀,47例无症状。查体：影像学检查发现胰腺或胰周占位性病变,44例为囊实性肿块,16例为单个囊性肿块,10例为实性肿块,7例为多个囊性肿块（囊〈3个）。肿瘤位于胰腺头部29个,体部25个,尾部17个,难以确定的部位6个（以胰尾部周围为主）。有或无完整包膜,不伴有胆总管和胰管扩张。病理特点为肿瘤实性部分由实性区、假乳头区及两者过渡区以不同比例混合而成。囊性区由坏死、液化组织及陈旧性出血组成。结论胰腺实性假乳头状瘤典型影像学表现为较大囊实性肿块,诊断比较容易,但对于表现为单个或多个囊性或单纯实性者,诊断需与有类似表现的胰腺其他疾病鉴别,特别对于老年患者需要与胰腺癌进行鉴别。影像学表现和病理学有一定特征,有助于诊断。     

Role of endoscopic ultrasonography in the diagnosis and treatment of cystic tumors of the pancreas

Endoscopic ultrasound (EUS) allows high resolution imaging of the pancreas. EUS is a very useful technique for evaluating morphological features of a cystic tumors of the pancreas. These features include thick wall type, tumor protruding type, thick septal type, microcystic type, thin septal type and simple type. Malignant cystic lesions may present as a hypoechoic cystic/solid mass or as a complex cyst and are frequently associated with a dilated main pancreatic duct. There is some overlap between EUS appearances of non-neoplastic and neoplastic cystic pancreatic lesions. EUS guided FNA of cystic pancreatic lesions can play an important role in the differential diagnosis of these lesions and deciding about the need for surgery by evaluating cytology and tumor markers such as CEA in cyst fluid. There is some emerging data on EUS guided treatment of cystic pancreatic tumors by injection of alcohol.     

Management of cystic neoplasms of the pancreas

BACKGROUND/AIMS: Despite the growing interest in cystic neoplasms of the pancreas, their diagnosis, treatment and prognosis are still obscure and controversial. METHODOLOGY: We studied, from September 1989 to July 1999, 21 patients (18 women) with an average age of 54.3 years who were submitted to surgical treatment for cystic neoplasms of the pancreas. Ultrasonography and computed tomography were performed in all patients. RESULTS: The treatment performed was surgical resection: cephalic gastroduodenopancreatectomy, 4 patients; body and tail pancreatectomy, 11 patients; only tail pancreatectomy, 2 patients; and two other patients were submitted to enucleation of one small lesion in the head of the pancreas. Internal drainage, through cystogastrostomy or cystojejunostomy, was performed in 3 cases. Site of tumor: body and tail region, 14 cases; head of the pancreas, 7 cases. Three patients had postoperative complications (respiratory tract infection, surgical wound infection, abdominal abscess). Three patients developed diabetes mellitus during the late postoperative period. One patient died 45 days after surgical procedure. CONCLUSIONS: Patients who present pancreatic cystic lesions should be submitted to surgery when local and medical conditions allow it and when intraoperative frozen biopsy excludes a pancreatic pseudocyst. If the nature of the lesion cannot be determined, it is better to err resecting a pseudocyst than by leaving or draining a cystic neoplasm, since these lesions are potentially curable.     

Heterotopic pancreatitis: gastric outlet obstruction due to an intramural pseudocyst and hamartoma

Heterotopic pancreas, usually a silent gastrointestinal malformation, may become clinically evident when complicated by chronic inflammation. We report a case of pancreatitis and extensive pseudocyst formation in the gastric antrum, which caused gastric outlet obstruction. The diagnosis was obscured by a history of emesis during pregnancy and a previously resected gastric polyp. The nature of the obstructive lesion was not diagnosed preoperatively in spite of endosonographic evaluation. Intraoperatively, a cystic tumor of the stomach wall was found, the lesion was excised, and a pyloroplasty was performed to close the excision site. Histology revealed heterotopic pancreatic tissue with chronic inflammation, fibrosis and pseudocyst formation and adjacent to this lesion a myoglandular hamartoma. The patient is symptom-free two years after surgery and no recurrence was found. The nature of heterotopic pancreatic tissue, its diagnosis and management are discussed.     

Macrocystic type of serous cystadenoma with a communication between the cyst and pancreatic duct

A 42-year-old woman with a cystic lesion in the head of the pancreas was evaluated by using abdominal ultrasonography, a computed tomographic scan, magnetic resonance imaging and endoscopic retrograde pancreatography. Multiple cystic lesions, 5 cm in diameter, which had papillary protrusion inside the cyst in the head of the pancreas and had the communication between the cysts and pancreatic duct, were determined. Pylorus-preserving pancreaticoduodenectomy was performed under the diagnosis of mucinous cystic neoplasm of the pancreas. Although the cut surface of the tumor showed a macrocystic tumor of 3 cm in diameter, part of the cyst wall was cavernous. A histopathological examination showed single-layered cuboidal cells, which lead to the diagnosis as being serous cystadenoma of the pancreas. Serous cystadenoma is a rare, almost benign pancreatic tumor. The macrocystic subtype of serous cystadenoma is even more rare. We describe a patient who had this macrocystic subtype of serous cystadenoma with a communication between the cyst and pancreatic duct. This case illustrates the difficulty in the diagnosis of cystic lesions in the pancreas, and might support the single category of cystic lesions of the pancreas.     

A Case of Postsurgical Pancreatic Pseudocyst Treated by Endoscopic Cystogastrostomy

Pancreatic pseudocyst after pancreatic surgery is a relatively rare condition and conservative therapy is the common treatment of choice. When symptoms persist or complications follow, however, surgical treatment is considered. There have been reports on endoscopic cystoenterostomy since the early 1980s. We herein describe a case of postsurgical pancreatic pseudocyst treated successfully by endoscopic cystogastrostomy. A nineteen-year-old female showing left hypochondralgia and back pain with elevation of her serum amylase level, who had undergone enucleation of a solid cystic tumor in the body of the pancreas, was referred to our department. She was diagnosed as having a pseudocyst of the pancreas 5.8×4.5 cm in size at the site of enucleation by US and CT. Endoscopic retrograde pancreatography and endoscopic ultrasonography performed simultaneously revealed obstruction of the main pancreatic duct and a cystic change in the body-tail of the pancreas just behind the gastric wall of the upper body. An extrinsic compression was seen in the posterior wall of the upper body of the stomach endoscopically. An incision was made using a sphincterotome. A pigtail stent, 7.2 Fr in size, was placed to keep the patency of the fistula, which was removed one and a half months later. Her symptoms showed great improvement immediately after the procedure. Follow-up CT demonstrated no recurrence of the pseudocyst.     

Cystic endocrine tumor of the pancreas.

A large cystic tumor in the pancreatic body was found incidentally in an 85-yr-old male. A distal pancreatectomy was performed after a diagnosis of cystadenocarcinoma. Microscopic examination of the resected specimen revealed a pancreatic cystic endocrine tumor; however, this tumor produced no symptoms. Immunohistochemical studies of the tumor cells showed positivity for gastrin, neuron-specific enolase, chromogranin A, and synaptophysin, and two cell types of neurosecretory granules were recognized in electron-microscopic studies. Although endocrine tumors of the pancreas are usually solid and cystic change occurs only rarely, such tumors should be considered in the differential diagnosis of patients who have a cystic lesion in the pancreas.     

EUS-Guided Antitumor Therapy for Pancreatic Tumors

Endoscopic ultrasound (EUS) is a very useful modality for the diagnosis and staging of pancreatic masses. With the advent of EUS-guided fine-needle aspiration technology, this modality has made a tremendous leap from imaging modality to histologic diagnosis and therapeutic intervention. EUS offers high-resolution images of and unparalleled access to the pancreas. After locating the tip of the echoendoscope in the duodenum or stomach, several drugs or local treatment modalities can be delivered directly into the pancreas. EUS-guided ethanol lavage with/without paclitaxel injection has been tested for the treatment of cystic tumors of the pancreas, with complete resolution of cystic tumor being observed in up to 70-80% of patients. Ethanol injection is also performed for the management of solid neuroendocrine tumors of the pancreas. Various type of EUS-guided injection have also been investigated for the treatment of pancreatic cancer. An activated allogenic mixed lymphocyte culture (Cytoimplant) was injected in patients with advanced pancreatic cancer. A replication-deficient adenovirus vector carrying the tumor necrosis factor-alpha gene was also delivered intratumorally by EUS. ONYX-015 is an oncolytic attenuated adenovirus that exhibits replication preferentially in malignant cells, causing cell death, and this has also been injected into pancreatic cancers under EUS guidance. EUS-guided local ablation therapies such as radiofrequency ablation, photodynamic therapy, and brachytherapy are also under investigation. EUS-guided fine-needle injection for various solid or cystic lesions is a rapidly expanding field. This article reviews the various applications of EUS for the treatment of pancreatic tumors.