|Year : 2015 | Volume
| Issue : 4 | Page : 272-274
Total pancreatic lipomatosis: A rare presentation
Onteddoo Joji Reddy1, Jamkhana Abdul Gafoor1, Gongalareddy Mohan Reddy2, Polysetty Obuleswar Prasad1
1 Department of Radiology, Government General Hospital, Kurnool, Andhra Pradesh
2 Department of Gastroenterology, Government General Hospital, Kurnool, Andhra Pradesh
|Date of Web Publication||14-Dec-2015|
Onteddoo Joji Reddy
Professor and Head of Department, Department of Radiodiagnosis, Kurool Medical College, Government General Hospital, Budhawarpet, Kurnool, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
Fatty replacement of the pancreatic parenchyma after chronic pancreatitis is not uncommon, and it may be focal or diffuse. Usually in chronic pancreatitis patients, atrophy of the parenchyma occurs followed by fat infiltration. In this case report, the patient had total fatty replacement of the entire pancreatic parenchyma with multiple calculi at the head of pancreas and in pancreatic duct at tail secondary to chronic pancreatitis, without exocrine and endocrine deficiency manifestations, which simulates a rare disease lipomatous pseudohypertrophy of pancreas.
Keywords: Computed tomography (CT), chronic pancreatitis, pancreatic lipomatosis
|How to cite this article:|
Reddy OJ, Gafoor JA, Reddy GM, Prasad PO. Total pancreatic lipomatosis: A rare presentation. J NTR Univ Health Sci 2015;4:272-4
| Case report|| |
A 26-year-old man came to the hospital with the chief complaint of acral pigmentation since 3 years and no other significant illness. Past history revealed on and off acute abdominal pain in epigastrium since childhood. Physical examination showed increased pigmentation in hands and feet and pallor present. Respiratory and cardiovascular system examination revealed no abnormality. No past history of tuberculosis, diabetes mellitus, or hypertension was present. With this clinical history, we suspect Addison's disease or megaloblastic anemia causing acral pigmentation. Routine blood tests showed dimorphic anemia with decreased levels of vitamin B12 (less than 45 pg/mL) levels and liver and renal function tests were normal. Serum cortisol levels were checked at 9 am, which were within normal limits. Chest x-ray was normal. Ultrasound abdomen revealed hyper reflective pancreatic head and body, and the tail of pancreas was not clearly delineated. Minimal free fluid within the pelvic cavity and mildly dilated small bowel loops were present. Contrast enhanced computed tomography (CT) of abdomen revealed no adrenal pathology and total pancreas was replaced by the fat (attenuation value = −100 HU) with no demonstrable normal pancreatic parenchyma [Figure 1]a. Evidence of Multiple calculi noted at the head, uncinate process [Figure 1]b and c and in pancreatic duct at tail without pancreatic duct dilatation [Figure 1]d. With these imaging findings at hand, we diagnosed total pancreatic lipomatosis secondary to chronic pancreatitis with endocrine and exocrine deficiencies. Colonoscopy and endoscopy were done that revealed no abnormality. Fecal fat estimation was done that showed absence of fat in stools. Pre- and postprandial blood sugar levels, serum amylase, lipase, total serum proteins, and albumin levels were also within normal range that rules out the possibility of endocrine and exocrine deficiencies.
|Figure 1: (a) Contrast enhanced CT abdomen showing total pancreatic parenchyma is replaced with fat, (b and c) CECT abdomen showing multiple calculi at head of pancreas, (d) CECT abdomen showing stenotic main pancreatic duct and calculi in pancreatic duct at tail of the pancreas|
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| Discussion|| |
The exact etiopathogenesis behind fatty replacement of pancreas is not known; however, several predisposing factors have been suggested. These include age related, obesity, diabetes mellitus, chronic pancreatitis, hereditary pancreatitis, pancreatic duct obstruction by calculus or tumor, and cystic fibrosis.  Marked pancreatic lipomatosis with atrophy has been observed in adult patients secondary to pancreatic duct obstruction by calculi or carcinoma. Under these circumstances, the obstructed pancreatic duct is stenotic rather than dilated. Important differentials in case of stenotic pancreatic duct include dorsal agenesis of pancreas, pancreatic carcinoma, and chronic pancreatitis. 
Lipomatous pseudohypertrophy of pancreas is a benign and rare disease in which the total pancreatic parenchyma is replaced by fat with preservation of islet cells and duct system without parenchymal atrophy radiologically appears as hypertrophy of pancreas. The specific etiology remains unknown.  These patients are usually asymptomatic or present with exocrine deficiency symptoms.
Pancreatic lipomatosis following chronic pancreatitis/carcinoma is focal or diffuse associated with parenchymal atrophy that manifests as exocrine and endocrine or only exocrine deficiency. In normal individuals, only 10% of parenchyma is sufficient for the maintenance of normal exocrine function. Exocrine deficiency manifestations (maldigestion) are seen only after severe parenchymal destruction and atrophy. In our case, the patient had past history of pancreatitis in childhood that may be idiopathic childhood chronic pancreatitis or tropical pancreatitis, and now he developed the total fat replacement of pancreatic parenchyma with multiple calculi that simulates lipomatous pseudohypertrophy of pancreas. Even though the total parenchyma of pancreas was replaced by fat in our patient, he had no exocrine or endocrine deficiency symptoms, which was a rare phenomenon.
Recognition of total fatty replacement of pancreas is important for radiologists. The role of ultrasound in the diagnosis of pancreatic steatosis is very limited; first, because the overlying bowel gas causes obscuration of the pancreas, and second, the fatty infiltration results in increased echogenicity of the pancreatic tissue making its differentiation difficult from normal retroperitoneal fat. However, cross-sectional imaging, CT and magnetic resonance imaging (MRI) play important roles in the evaluation of pancreatic disease. CT is particularly useful in detecting specific etiologies, for example, pancreatic duct obstruction by the calculus or tumor. Unenhanced CT has negative attenuation value of pancreatic tissue replaced by the fat, therefore, can reliably diagnose diffuse fatty change involving the pancreas. However, focal fatty change cannot be diagnosed confidently with CT alone, as on postcontrast images the normal pancreatic parenchyma entrapped between fatty replacement area shows contrast enhancement simulating a true mass.  Chemical shift MRI has advantage over CT in confirming the presence of focal fatty replacement of the pancreas. Magnetic resonance cholangiopancreatography (MRCP)/endoscopic retrograde cholangiopancreatography (ERCP) demonstrates the status of pancreatic duct and the biliary tree. Selective pancreatic angiography is especially useful in differentiating pancreatic lipomatosis from dorsal agenesis by showing the pancreatic circulation. 
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| References|| |
Soyer P, Spelle L, Pelage JP, Dufresne AC, Rondeau Y, Gouhiri M, et al
. Cystic fibrosis in adolescents and adults: Fatty replacement of the pancreas- CT evaluation and functional correlation. Radiology 1999;210:611-5.
Nakamura M, Katada N, Sakakibara A, Okumura N, Kato E, Takeichi M, et al
. Huge lipomatous pseudohypertrophy of the pancreas. Am J Gastroenterol 1979;72:171-4.
Siegler DI. Lipomatous pseudohypertrophy of the pancreas associated with chronic pulmonary suppuration in an adult. Postgrad Med J 1974;50:53-5.
Matsumoto S, Mori H, Miyake H, Takaki H, Maeda T, Yamada Y, et al
. Uneven fatty replacement of the pancreas: Evaluation with CT. Radiology 1995;194:453-8.
Baek SY, Lee SC, Kim MY, Lee MG, Cho KS, Auh YH. CT findings of pancreas lipomatosis and associated diseases. J Korean Radiol Soc 1992;28:749-53.