What are the other Names for this Condition? (Also known as/Synonyms)

• Acinar Cystic Transformation of Pancreas
• Cystic Lesion of Pancreatic Acinar Cells
• Pancreatic Acinar Cell Cystadenoma

What is Acinar Cell Cystadenoma of Pancreas? (Definition/Background Information)

• Acinar Cell Cystadenoma of Pancreas is a rare and benign cystic lesion of the pancreas, typically lined by cells exhibiting acinar cell like properties
• The pancreas, an important organ of the digestive system, can be functionally divided into two parts, exocrine (constituting 95% of the organ) and endocrine. The acinar cells are the functional units of the exocrine pancreas, secreting digestive enzymes
• Anatomically, the pancreas is divided into 3 regions, namely, the head, body, and tail. Acinar Cell Cystadenoma of Pancreas can form in all three regions of the pancreas, although more cysts are diagnosed in the head region of the organ
• The condition may occur in individuals of all ages, but is predominantly seen in females. Acinar Cell Cystadenoma of Pancreas may cause abdominal pain, nausea and vomiting, and weight loss. It can cause complications, such as gastrointestinal and biliary tract obstruction
• The cause of formation of the Acinar Cell Cystadenoma of Pancreas is believed to be the distention of acinar units, which expand and coalesce with other units to form cysts
• The affected individuals may present with abdominal discomfort, and the finding of a lesion is most often incidental. However, once a lesion is detected, a detailed radiological and pathological examination is typically performed to arrive at an accurate diagnosis. The diagnosis of Acinar Cell Cystadenoma of Pancreas can be confirmed through a tissue biopsy
• Surgical excision of the cyst is the most recommended treatment for Acinar Cell Cystadenoma of Pancreas, which can help relieve the symptoms. However, currently, there are no known methods to prevent the occurrence of this pancreatic tumor

Who gets Acinar Cell Cystadenoma of Pancreas? (Age and Sex Distribution)

• Acinar Cell Cystadenoma of Pancreas is a rare and benign lesion of the pancreas. Less than 100 cases have been reported in the medical literature
• The lesions can occur in individuals of all ages, with the average age at presentation being 40 years
• Both genders may be affected, although the condition predominantly occurs in women, at a ratio of female-male ratio of 9:1 

What are the Risk Factors for Acinar Cell Cystadenoma of Pancreas? (Predisposing Factors)

The risk factors for Acinar Cell Cystadenoma of Pancreas may include:

• Female gender
• Smoking habit (in one study, all affected subjects were smokers)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Acinar Cell Cystadenoma of Pancreas? (Etiology)

• It is theorized that Acinar Cell Cystadenoma of Pancreas is caused by dilatation or distention of acinar units in the initial stages
• These expanded units have thin walls, and merge with other similar units to form large cystic structures
• The cyst can either be with a single sac (unilocular) or develop into multiple sacs (multilocular), contain clear fluid, and range in size from 2-15 cm
• An individual may have single or multiple cysts in the pancreas. The walls of the cyst are smooth and lined by acinar epithelium

What are the Signs and Symptoms of Acinar Cell Cystadenoma of Pancreas?

The signs and symptoms of Acinar Cell Cystadenoma depend on the size of the cyst, which can range between 2-15 cm. Small cysts usually do not cause any symptoms. But, occasionally they may become painful, if they compress surrounding structures.

When symptoms do occur, they may include

• Abdominal pain, back pain
• Loss of appetite
• Weight loss
• Indigestion
• Yellowing of skin (jaundice)
• Nausea and vomiting
• Dark-colored urine

How is Acinar Cell Cystadenoma of Pancreas Diagnosed?

Frequently, pancreatic cysts are difficult to detect/diagnose in the early stages, and may often be incidentally found. However, once an abnormality is identified, the following methods may be employed for an accurate diagnosis of Acinar Cell Cystadenoma of Pancreas, as well as to rule out malignancies:

• A thorough physical examination and an evaluation of complete medical history
• Blood test to check for serum amylase levels
• Complete blood count with differential
• Blood tests that may involve tumors markers, such as:
  • Carcinoembryonic antigen (CEA)
  • CA 19.9
  • CA 15.3
  • Alpha fetoprotein (AFP)
• Radiological studies that may include:
  • Abdominal ultrasound: A procedure where high-frequency sound waves are used to produce real-time images
  • Endoscopic ultrasound: It is a minimally-invasive procedure that uses high-frequency sound waves to obtain detailed images of the pancreas
  • CT scan of abdomen
  • MRI scan of abdomen: It helps produce high-quality pictures of certain body parts including the tissues, muscles, nerves, and bones
  • Positron emission tomography (PET): A PET scan is a nuclear medicine imaging technique that generates three-dimensional images to show how tissue and organs are functioning. A small amount of radioactive material may be injected into a vein, inhaled or swallowed
• Additionally, the following magnetic resonance imaging procedures may be used particularly in individuals suspected of having pancreatic tumor/cancer:
  • MR cholangiopancreatography (MRCP)
  • MR angiography (MRA)
• Percutaneous trans-hepatic cholangiography (PTC): A contrast material is injected into the bile ducts to visualize the structure
• Endoscopic retrograde cholangiopancreatography (ERCP): This technique is used when symptoms of pancreatic cancer are present in the individual. A special equipment and dye injections are used to obtain a series of images. If required, a biopsy sample may also be collected during the procedure
• Invasive diagnostic procedures such as:
  • Laparoscopy: A special device is inserted through a small hole into the abdomen, to visually examine it. If necessary, a tissue sample is obtained for further analysis. Exploration of the abdomen using a laparoscope is called ‘exploratory laparoscopy’
  • Laparotomy: The abdomen is opened through an incision for examination, and if required, a biopsy sample obtained. Exploration of the abdomen using laparotomy procedure is called ‘exploratory laparotomy’
• Tissue biopsy: A tissue biopsy of the cyst or mass is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
• Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies, to assist in the diagnosis

The tissue for diagnosis can be procured in multiple different ways, and they include:

• Fine needle aspiration (FNA) biopsy of the pancreatic tumor:
  • A fine needle aspiration of the cyst has limited diagnostic value; however, the aspirated fluid can be analyzed for a variety of proteins such as CEA, CA 19.9, CA 15.3, alpha fetoprotein, and others. Such an evaluation will help in arriving at a diagnosis and classifying the type of cyst
• Core biopsy of the pancreatic tumor
• Open biopsy of the pancreatic tumor
• During endoscopic retrograde cholangiopancreatography (ERCP)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Acinar Cell Cystadenoma of Pancreas?

No major complications have been reported due to Acinar Cell Cystadenoma of Pancreas. However, if the cysts become large, they may potentially lead to the following conditions:

• Gastrointestinal tract obstruction and biliary tract obstruction (causing jaundice)
• Compression of adjoining organs, if the cyst size is large, affecting the function of the involved organ(s)
• Injury to local region

How is Acinar Cell Cystadenoma of Pancreas Treated?

• Acinar Cell Cystadenoma of Pancreas is treated by surgical removal of the cyst(s)
• Post-operative care is important: One must maintain minimum activity levels, until the surgical wound heals
• Follow-up care with regular screening and check-ups are important and encouraged

How can Acinar Cell Cystadenoma of Pancreas be Prevented?

At the present time, no specific methods or guidelines exist for the prevention of Acinar Cell Cystadenoma of Pancreas.

• Since some study subjects had a history of smoking cigarettes, smoking cessation may be helpful in reducing one’s risk for this type of tumor
• Regular medical screening at periodic intervals with blood tests and scans may be necessary for those diagnosed with Acinar Cell Cystadenoma of Pancreas

What is the Prognosis of Acinar Cell Cystadenoma of Pancreas? (Outcomes/Resolutions)

Acinar Cell Cystadenoma of Pancreas is a benign condition and the prognosis is generally favorable.

• The most reliable prognostic factor is dependent on whether the cyst can be completely removed through surgery or not
• Individuals, following complete surgical resection of the tumor, have an excellent prognosis
• Clinical follow-up of some affected individuals in a study for approximately 3.5 years, did not show any recurrence or malignant transformation of acinar cell cysts 

Additional and Relevant Useful Information for Acinar Cell Cystadenoma of Pancreas:

It has been suggested that the term Acinar Cell Cystadenoma of Pancreas may be misleading, and that “acinar cystic transformation” be used in its place. This is due to the unresolved issue of whether the cysts have non-neoplastic or neoplastic origins.