A small pancreatic hamartoma with an obstruction of the main pancreatic duct and avid FDG uptake mimicking a malignant pancreatic tumor: a systematic case review

Imaging and histopathologic characteristics of typical pancreatic hamartoma: a case report and literature review

Background

Pancreatic hamartoma, a rare benign non-neoplastic condition, presents challenges in differentiating from other pancreatic diseases due to its atypical imaging and unreliable biopsy results. In this study, we present a case of pancreatic hamartoma and conduct a comprehensive review of relevant literature to outline its characteristic features, aiming to underscore its clinical relevance and implications.

Case presentation

A 63-year-old man presented with a pancreatic mass, discovered during evaluation of abdominal pain and distension. Laboratory tests were largely unremarkable. Ultrasound revealed a hypoechoic mass in the head of the pancreas. Subsequent computed tomography and magnetic resonance imaging demonstrated an inhomogeneous mass with a clear boundary in the uncinate process of the pancreas. Furthermore, a distinct delayed enhancement pattern was noted on imaging. Histopathological examination confirmed the diagnosis of pancreatic hamartoma.

Conclusions

Preoperative diagnosis of pancreatic hamartoma remains challenging. Imaging modalities can play a crucial role in facilitating accurate diagnosis and potentially avoiding unnecessary surgical intervention in patients with this condition.

A case of solid-type pancreatic hamartoma presenting high apparent diffusion coefficient value: histopathological correlation and literature review

Pancreatic hamartoma is a rare tumor-like malformation and could mimic other pancreatic tumors including malignant neoplasm. Due to its rarity, magnetic resonance (MR) imaging findings including those diffusion-weighted (DW) imaging have not been clarified. We present a curious case of pancreatic hamartoma presenting high apparent diffusion coefficient (ADC) value with histopathological correlation. A 49-year-old woman with a pancreatic mass found incidentally on ultrasonography for medical checkup was referred to our institution for further examination and treatment because it slightly enlarged in the follow-up examination. Contrast-enhanced computed tomography (CT) and gadoxetic acid disodium-enhanced MR imaging revealed a well-demarcated solid mass of 13 mm in diameter in the pancreas body, which was gradually and homogeneously enhanced in the delayed/transient phase. It showed hyper intensity on T2-weight and DW images, and the mean ADC value was high (1.86 × 10^-3mm²/s). Laparoscopic distal pancreatectomy was conducted with suspicious preoperative diagnosis of pancreatic hypovascular neuroendocrine neoplasm (NEN). Histologically, the mass consisted of many disarranged small ducts without atypia embedded in abundant fibrous stroma and contained scant fatty tissue in the periphery, which was not identified on CT and MR images. There were no islets and peripheral nerves throughout the mass. Finally, it was pathologically diagnosed as a solid-type pancreatic hamartoma. Based on radiological-pathological correlation, it was considered that the abundant fibrous stroma and both the widely distributed myxomatous periductal stroma and scattered edematous stroma corresponded with delayed homogenous enhancement on CT/MR images and high ADC value, respectively. Although it is difficult to distinguish solid-type pancreatic hamartoma from other solid pancreatic neoplasms including hypovascular NEN on the basis of usual radiological findings, the high ADC value reflecting the specific pathology may be helpful for the differential diagnosis.

Rare case of pancreatic lipomatous hamartoma

A middle-aged man had an incidental finding of 10.1 cm lipomatous mass arising from pancreatic body/neck detected on CT scan. He was asymptomatic. He underwent surgical resection of the mass due to concern for malignancy. His postoperative course was complicated by a high-volume pancreatic leak of approximately 900 mL/day. He underwent endoscopic retrograde cholangiopancreatography and insertion of a pancreatic stent, with some improvement in the pancreatic leak. His leak eventually settled after 3 months. The final histopathology showed lobules of mature adipocytes with small islands of disorganised benign pancreatic ducts and acini interspersed within them, suggestive of pancreatic hamartoma of lipomatous variant. Pancreatic lipomatous hamartomas are rare and are often diagnosed on final histopathology when the initial resection was performed due to diagnostic uncertainty or concern for malignancy. It is a benign lesion with an indolent course and must be discriminated from other lipomatous lesions of the pancreas. An awareness of the condition is important to help guide management.

Pancreatic Hamartoma Difficult to Diagnose Preoperatively

Abdominal ultrasonography in a 70-year-old woman showed a hypoechoic mass, 14 mm in diameter, in the pancreatic body. Computed tomography showed a mass with contrast effect in the pancreatic body. Test results for endocrine factors or tumor markers were normal. The initial consideration was nonfunctional pancreatic neuroendocrine tumor. Over 8 years of monitoring, the tumor diameter increased to 18 mm, until pancreatic tumor enucleation was performed. The postoperative diagnosis was pancreatic hamartoma, a rare type of benign pancreatic tumor. The preoperative diagnosis of pancreatic hamartoma is difficult, but consideration must be given to the possibility of hamartoma when encountering pancreatic tumors.

Pancreatic lipomatous hamartoma mimicking other pancreatic tumor: a case report and literature review

Pancreatic lipomatous hamartoma (PLH) is an extremely rare benign entity that forms a mass-like lesion. PLH lacks distinct features, and can be preoperatively misdiagnosed as a pancreatic tumor with lipomatous components, including pancreatic lipomatosis, lipoma, liposarcoma, and malignant tumors with fatty degeneration. Here, we report a case study of PLH in a 73-year-old male who presented with abdominal pain. Abdominal-enhanced computed tomography and magnetic resonance imaging revealed a 4.3×4-cm solid mass with a lipomatous component in the pancreatic head, and the mass displayed a centripetal pattern of contrast enhancement. The patient was preoperatively diagnosed with pancreatic liposarcoma, and subsequently underwent a pancreatoduodenectomy. The postoperative pathology and immunohistochemical analyses confirmed the diagnosis of PLH, which primarily contained mature adipocytes, small ducts, and a few well-preserved pancreatic acini. Although this disease is rare, we suggest that PLH should be considered during the differential diagnosis of pancreatic lesions with lipomatous components. Consideration of the potential for PLH disease might reduce the number of unnecessary resections.

FDG PET/CT Imaging of Pancreatic Plasmacytoma

A 56-year-old man underwent F-FDG PET/CT to evaluate possible pancreatic cancer, which was revealed by CT. The images showed a solid lesion with peripherally increased FDG activity in the tail of the pancreas, as well as hypermetabolic lesions in the lumbar spine and rib. Pathological examination following lumbar biopsy demonstrated multiple myeloma. Five months after chemotherapy, follow-up FDG PET/CT showed cystic change in the pancreatic lesion without elevated metabolism.

The Role of Positron Emission Tomography in Pancreatic Cancer and Gallbladder Cancer

18F-FDG-PET is complementary to conventional imaging in patients with clinical suspicion for exocrine pancreatic malignancies. It has similar if not superior sensitivity and specificity for detection of cancer, and when combined with contrast enhanced anatomic imaging of the abdomen, can improve diagnostic accuracy and aid in staging, assessment for resectability, radiation therapy planning, and prognostication. Various metabolic pathways affect FDG uptake in pancreatic ductal adenocarcinoma. The degree of uptake reflects histopathology, aggressiveness, metastatic potential, and metabolic profile of malignant cell and their interaction with cancer stroma. After treatment, FDG-PET is useful for detection of residual or recurrent cancer and can be used to assess and monitor response to therapy in unresectable or metastatic disease. The degree and pattern of uptake combined with other imaging features are useful in characterization of incidental pancreatic lesions and benign processes such as inflammation. Several novel PET radiopharmaceuticals have been developed to improve detection and management of pancreatic cancer. Gallbladder carcinoma is typically FDG avid and when anatomic imaging is equivocal PET can be used to assess metastatic involvement with high specificity and inform subsequent management.

A case of pancreatic hamartoma with characteristic radiological findings: radiological-pathological correlation

Pancreatic hamartoma is a rare benign tumor. Its preoperative diagnosis is challenging. We present a case of pancreatic hamartoma whose radiological-pathological correlation was evaluated in detail. A 53-year-old man was referred to our institution for diagnosis and treatment. Contrast-enhanced computed tomography (CT) and magnetic resonance image revealed a 3.5 cm long tumor arising from the head of the pancreas with cystic and solid components, the latter of which was gradually and inhomogeneously enhanced in the delayed phase. Fluorodeoxyglucose (FDG) positron emission tomography/CT revealed slight FDG uptake in the solid component. Histologically, a number of pancreatic lobule-like structures, which were mainly composed of aggregates of small ducts embedded in concentric fibrous stroma with no apparent islets or peripheral nerves, were observed in the solid component, whereas multiple dilated ducts were seen in the cystic region. The solid component also contained a narrow area of edematous fibrous stroma with low vessel density, which corresponded with the unenhanced part in the inhomogeneously enhanced solid component. There was no remarkable cytological atypia throughout the mass. A pathological diagnosis of pancreatic hamartoma was made. The radiological findings agree well with the pathological findings. When a pancreatic tumor is of the solid type, preoperatively diagnosing it as pancreatic hamartoma is not possible. However, when a pancreatic tumor with cystic and solid components is inhomogeneously enhanced in contrast-enhanced studies, a diagnosis of pancreatic hamartoma can be considered.

A typical case of resected pancreatic hamartoma: a case report and literature review on imaging and pathology

Background

Pancreatic hamartomas are rare entities and difficult to diagnose before resection. We report a case of resected pancreatic hamartoma and literature review of typical characteristics of the lesion.

Case presentation

A 78-year-old man presented with a mass in his pancreas, which was incidentally identified when he experienced pneumonia. No remarkable symptoms were observed, and laboratory tests showed no abnormalities, except a slight carcinoembryonic antigen elevation. Enhanced computed tomography and magnetic resonance imaging showed a well-demarcated solid mass with heterogeneous contrast that was 2 cm in size. A gradual enhancement pattern was also observed. The biopsy revealed no specific findings; therefore, surgical resection was necessitated to confirm the diagnosis. Histopathologically, ducts, acinar cells, and adipose cells without atypia were observed among abundant fibrous stroma, but islets of Langerhans and peripheral nerves were absent. An immunohistochemical examination demonstrated CD34 and c-kit positive staining in the stromal cells, S-100 positivity in the adipose cells, and a lack of elastic fibers in the duct walls. The lesion was diagnosed as a pancreatic hamartoma.

Conclusion

Asymptomatic pancreatic hamartomas can avoid resection. A careful consideration of imaging and appropriate immunohistochemistry of biopsy specimen may facilitate accurate diagnosis before resection. Therefore, sufficient recognition of the characteristics of pancreatic hamartomas is desirable.

Imaging findings for pancreatic Hamartoma: two case reports and a review of the literature

BACKGROUND

Pancreatic hamartoma is an extremely rare benign disease, and previous reports have provided little detail regarding its appearance in imaging. As a result, we report the imaging findings for two cases of pancreatic hamartoma.

CASE PRESENTATION

One 57-year-old female patient and one 69-year-old male patient presented with pancreatic lesions incidentally detected by US; CT and MRI revealed a 2.9-cm cystic and solid lesion and a 1.4-cm solid lesion, respectively. US showed a hypoechoic well-defined mass in the pancreatic head. The plain CT indicated that the internal density was uneven, and the lesions showed obvious progressive enhancement. The MRI-T2WI showed iso- to high-intensity, the DWI showed iso-intensity, and the masses also all showed obvious progressive enhancement. Histopathological studies confirmed the diagnosis of pancreatic hamartoma.

CONCLUSION

Pancreatic hamartoma is an extremely rare tumour with benign features, such as no dilatation of the MPD and well-defined, slight hyperintensity or iso-intensity on T2WI and iso-intensity on DWI, with obvious progressive enhancement. Therefore, detailed review of multiple imaging modalities may help in diagnosis of PH and prevent unnecessary surgery for patients with this diagnosis.

A case of pancreatic hamartoma pathologically confirmed after robot-assisted pancreaticoduodenectomy

Pancreatic hamartoma is a rare benign tumor that can be easily misdiagnosed due to its rarity. Its diagnostic ambiguity demands surgical resection for confirmation. We reported a 54-year-old female patient with a pancreatic hamartoma that was pathologically confirmed after surgery, and we reviewed all the reported literature for adult pancreatic hamartomas. With the advancement of techniques for minimally invasive surgery, laparoscopic or robotic pancreatectomy can be safely performed on benign or low-grade malignant tumors in which the diagnosis is uncertain.