Multiple solid pancreatic hamartomas: A case report and review of the literature

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.

Comments and illustrations of the European Federation of Societies for Ultrasound in Medicine guidelines: Rare pancreatic tumors, ultrasound and contrast-enhanced ultrasound features-Malignant mesenchymal tumors

Rare malignant mesenchymal pancreatic tumors are systematized and reported in this review. The focus is on the appearance on imaging. The present overview summarizes the data and shows that not every pancreatic tumor corresponds to the most common entities of ductal adenocarcinoma or neuroendocrine tumor.

Giant Pancreatic Myoepithelial Hamartoma in a Patient With Familial Insulin-Dependent Diabetes Mellitus

ABSTRACT

Pancreatic myoepithelial hamartoma is a rare, benign solid and cystic lesion of the pancreas. We present the first case of an adult with a giant myoepithelial hamartoma extending throughout the pancreas in a patient with diabetes in 4 immediate family members. The patient is a 46-year-old man presented with recurrent acute pancreatitis. Computed tomographic imaging showed that the head and body of the pancreas were replaced by a solid-cystic mass with focal calcification. Medical history includes insulin-dependent diabetes mellitus (IDDM) diagnosed at age 30. Endoscopic ultrasound-guided fine-needle aspiration showed pancreatic acinar tissue and smooth muscle without evidence of malignancy. Total pancreatectomy was performed because of the diffuse nature of the cystic disease and preexisting IDDM. The histopathologic diagnosis was consistent with myoepithelial hamartoma. In addition, there was a family history of IDDM and hamartomatous cyst resection in the paternal grandmother. We report the first case of diffuse pancreatic myoepithelial hamartoma with near total replacement of the entire pancreatic parenchyma, and the first reported case associated with a family history of heritable IDDM. Improved knowledge of the genetics, development, and malignant potential of such rare diseases is critical to determine appropriate management for patients.

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.

Biliary Duct Hamartomas: A Systematic Review

Biliary duct hamartomas are benign intrahepatic bile duct lesions. Despite being primarily incidental findings on imaging, these lesions can provide a diagnostic conundrum due to their shared characteristics with malignant tumors. The goal of this systematic review is to offer a thorough clinical profile of biliary duct hamartomas. There were 139 cases of biliary duct hamartomas identified in a structured systematic review of the literature. Patient demographics, clinical presentation, significant laboratory and imaging data, diagnostic modalities, treatment choices, and outcomes were all studied and reported. Biliary duct hamartomas present with mild symptoms and laboratory abnormalities, and while being visible on imaging, the results are non-specific and may require biopsy in case of red flag signs such as weight loss and a progressive increase in the size of the lesion. Furthermore, there are currently no published guidelines for the treatment of biliary duct hamartomas, and many people have had surgery despite the clinically benign nature of these abnormalities. As per the findings of the study, individuals who exhibit signs of malignancy should be investigated further. Eyeballing for red flag symptoms, followed by a specialized imaging scan and invasive treatment, is the three-step approach to biliary duct hamartomas. Since our recommendations include a shift in strategy and do not contradict existing rules, there are likely to be few roadblocks to improvement; the key barriers being technological equipment and image quality. In this study, we intended to pave the way for future research in the field. In our opinion, the next decade will bring a better understanding of the characteristics of biliary hamartomas, disease symptoms, and better recognition of any suspicious features. These indications will aid in reducing the number of unneeded surgical or invasive operations. Finally, the findings of these future studies will allow the medical community to improve and provide the best care possible.

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.

Inflammatory and tumor-like lesions of the pancreas

Inflammatory/tumor-like lesions of the pancreas represent a heterogeneous group of diseases that can variably involve the pancreatic gland determining different signs and symptoms. In the category of inflammatory/tumor-like lesions of the pancreas, the most important entities are represented by chronic pancreatitis, which includes alcoholic, obstructive and hereditary pancreatitis, paraduodenal (groove) pancreatitis, autoimmune pancreatitis, lymphoepithelial cyst, pancreatic hamartoma and intrapancreatic accessory spleen. An in-depth knowledge of such diseases is essential, since they can cause severe morbidity and may represent a potential life-threatening risk for patients. Furthermore, in some cases the differential diagnosis with malignant tumors may be challenging. Herein we provide a general overview of all these categories, with the specific aim of highlighting their most important clinic-pathological hallmarks to be used in routine diagnostic activities and clinical practice.

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.

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.

Pancreatic Lipomatous Hamartoma: A Hitherto Unrecognized Variant

Pancreatic masses consisting of lipomatous components clinically include lipoma, liposarcoma, lipomatous pseudohypertrophy of the pancreas, fat-containing neoplasms such as perivascular epithelioid cell tumor, and malignant neoplasm with lipoid degeneration. We present pancreatic lipomatous hamartoma, which has not been reported hitherto. A solid pancreatic mass was detected from a computed tomographic scan check-up in each of 3 cases of Japanese men. Macroscopically, well-demarcated solid lipomatous masses were detected at the uncus, body, and tail of the pancreas, respectively. Microscopically, the masses predominantly consisted of mature adipocytes with no atypia, but contained characteristics components of pancreatic hamartoma, such as small ducts, a well-preserved acinar structure, and/or fibrous stroma. On the basis of the unique features, lack of islets and absence of periductal elastic fibers, these tumors are a distinct variant of pancreatic hamartoma. Furthermore, high-mobility group AT-hook 2 expression in the fibro-adipocytes of this tumor indicated that these cells are an integral component of the pancreatic lipomatous hamartoma. Consequently, the unique tumors described herein are pancreatic lipomatous hamartoma, which must be discriminated from other lipomatous lesions of the pancreas.

Computed tomography and magnetic resonance imaging findings of pancreatic hamartoma: A case report and literature review

Pancreatic hamartoma is a rare benign malformation that resembles a neoplasm and may be mistaken for a malignancy. The imaging findings of pancreatic hamartoma are not well established, as only one radiological case report has been described since 1983. Herein, we discussed a case of pancreatic hamartoma in a 35-year-old woman and conducted a literature review focused on imaging findings and differential diagnosis of pancreatic hamartoma. Increased late enhancement on post-contrast dynamic study and absence of diffusion restriction may be characteristic MR imaging findings of pancreatic hamartoma that may narrow the differential diagnosis of hypervascular pancreatic lesions.

Benign Tumors and Tumorlike Lesions of the Pancreas

The pancreas is a complex organ that may give rise to large number of neoplasms and non-neoplastic lesions. This article focuses on benign neoplasms, such as serous neoplasms, and tumorlike (pseudotumoral) lesions that may be mistaken for neoplasm not only by clinicians and radiologists, but also by pathologists. The family of pancreatic pseudotumors, by a loosely defined conception of that term, includes a variety of lesions including heterotopia, hamartoma, and lipomatous pseudohypertrophy. Autoimmune pancreatitis and paraduodenal ("groove") pancreatitis may also lead to pseudotumor formation. Knowledge of these entities will help in making an accurate diagnosis.

Rare Tumors and Lesions of the Pancreas

There are a few entities that account for most solid and cystic masses of the pancreas. The pancreas harbors a wide array of diseases, including adenocarcinoma, and its variants, such as anaplastic and adenosquamous carcinoma. Other neoplasms include acinar cell carcinoma, solid pseudopapillary tumor, and sarcomas. Benign lesions include hamartomas, hemangiomas, lymphangioma, and plasmacytoma. Isolated metastases include renal cell carcinoma, melanoma, and other carcinomas. Benign inflammatory conditions, such as autoimmune pancreatitis and groove pancreatitis can also mimic solid neoplasms of the pancreas.

Pancreatic hamartoma in a premature Trisomy 18 female

Pancreatic hamartomas are extremely rare tumors in adults and even more so in children. They are lesions characterized by acinar, islet and ductal components found in varying proportions and in a disorganized pattern. We report a case of a premature female with trisomy 18 diagnosed by amniocentesis. The newborn was delivered by cesarean section at thirty-three weeks of gestation and expired within one hour of birth. Postmortem examination exhibited numerous features associated with Trisomy 18 including lanugo on the torso and arms, micrognathia, microstomia, left low-set ear with small flat pinna, closed ear canal, clenched fists with overlapping fingers, rocker-bottom feet, narrow pelvis, large right diaphragmatic hernia and left pulmonary hypoplasia. Microscopic examination of the pancreas revealed an area, 1.2 cm in greatest dimension, with branching ducts and cysts lined by cuboidal epithelium intermingled within primitive mesenchymal proliferation and exocrine glands. The cysts measured up to 0.2 cm and were surrounded by a collarette of proliferating spindle cells as highlighted by Masson's trichrome stain. A diagnosis of pancreatic hamartoma was rendered. A total of thirty-four cases of pancreatic hamartomas have been reported in the literature including twenty-seven in adults, five in children and two in newborns. Our case may be the third pancreatic hamartoma reported in association with Trisomy 18. We recommend that careful examination of the pancreas be performed in individuals with Trisomy 18 to further characterize this lesion as one of the possible abnormal findings associated with this syndrome.

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

BACKGROUND

Pancreatic hamartomas are extremely rare and may be misdiagnosed as malignant tumors. We report herein a case of a small, solid-type pancreatic hamartoma.

CASE PRESENTATION

A 72-year-old female was incidentally detected pancreatic lesion by ultrasonography. Computed tomography and magnetic resonance imaging revealed a 2.0-cm solid lesion. The main pancreatic duct (MPD) was obstructed by the lesion in the head of the pancreas, and the upstream MPD was dilated. ¹⁸F-fluorodeoxyglucose (FDG) accumulated avidly in the lesion and increased in FDG intensity from the early to the delayed images. The histopathological studies confirmed the diagnosis of pancreatic hamartoma. Immunohistochemically, the cell membrane of the accessory glands and ducts showed homogeneous expression of glucose transporter type I and hexokinase II.

CONCLUSION

Pancreatic hamartomas causing dilatation of the MPD are extremely rare, and this appears to be the first case of a hamartoma to take up FDG avidly. It was a rare occurrence and should be noted that pancreatic hamartomas can cause an obstruction of the MPD and show avid FDG uptake, thereby mimicking malignant pancreatic tumors.

Intramural chondroid hamartoma in the distal esophagus in an adult: A case report and review of the literature

Hamartoma of the esophagus is a rare lesion and the number of cases reported in the literature to date is limited. The majority of hamartomas are intraluminal tumors located in the upper third of the esophagus. Histopathologically, the majority of these tumors comprise a mixture of adipose tissue, skeletal/smooth muscle tissue, vascular components and fibrous connective tissue. We herein present the case of a 33-year-old man with an intramural chondroid hamartoma located in the lower third of the esophagus. The patient underwent esophagotomy and the histopathological examination revealed that the tumor was mainly composed of chondroid tissue (60%) admixed with adipose tissue (25%) and fibrous connective tissue (15%). The aim of this study was to describe another variant of esophageal hamartoma, which exhibits a versatile phenotype.

Pancreatic hamartoma, a rare benign disease of the pancreas: A case report

Pancreatic hamartoma is an extremely rare, non-neoplastic, mass-forming lesion that may be mistaken for malignancy, and the pre-operative diagnosis is particularly challenging. The published literature contains only 23 cases of pancreatic hamartoma. The majority of the cases reported patients with a single benign tumor-like disease that received a pancreatectomy. Immunohistochemical findings confirmed the diagnosis following surgery. The current study reports the case of a 53-year-old female who presented to the Department of Abdominal Surgery, Chinese Academy of Medical Sciences, Cancer Hospital (Beijing, China), due to abdominal pain. Abdominal magnetic resonance imaging revealed a 22×14-mm mass in the head of the pancreas. The patient was pre-operatively diagnosed with a pancreatic space-occupying lesion, and subsequently underwent a pancreaticoduodenectomy. The post-operative course was uneventful. Histological examination of the resected lesion resulted in a diagnosis of pancreatic hamartoma. There were no signs of recurrence at 55 months post-surgery.

Pancreatic hamartoma: a case report and literature review

Background

Pancreatic hamartoma is an extremely rare benign disease of the pancreas. Only 30 cases have been reported to date.

Case presentation

A 68-year-old man presented with an asymptomatic solid and multi-cystic lesion in the uncus of the pancreas, incidentally detected on abdominal enhanced computed tomography. The tumor was found to be a well-demarcated solid and multi-cystic lesion without any enhancement, measuring 4 cm in diameter. After 28 months of follow-up, the tumor enlarged. At 31 months after initial diagnosis, the patient underwent surgical resection because it was difficult to clinically determine whether the tumor was malignant or not. Macroscopically, the solid tumor consisted of yellow adipose tissue with a smooth thin capsule confined to the pancreatic uncus. The inner structure of the tumor consisted of multiple cysts with a white nodule between the cysts. Histologically, the solid part and the multi-cystic portion consisted of mature adipose tissue and colonization of dilated pancreatic ducts with mild fibrosis, respectively. Immunohistochemical findings revealed cytokeratin 7 and 19 positive staining in the epithelial cells of the ducts. Adipose tissue showed positive staining for S-100 protein and there were only a few MIB-1 positive cells. The tumor was then diagnosed as a pancreatic hamartoma.

Conclusion

Beside on the above findings, we suggest that the term “well-demarcated solid and cystic lesion with chronological morphological changes” could be a clinical keyword to describe pancreatic hamartomas.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0419-2) contains supplementary material, which is available to authorized users.

Importance of NAB2-STAT6 Fusion in the Diagnosis of Pancreatic Solitary Fibrous Tumor with Hamartoma-Like Features: A Case Report and Review of the Literature

We report a case of pancreatic hamartoma-like solitary fibrous tumor which was differentiated from pancreatic hamartoma with the detection of NAB2-STAT6 fusion, a specific mutation for solitary fibrous tumors. A pancreatic well-demarcated solid nodule, 21 × 17 mm, of 82-year-old man was surgically enucleated. Microscopic findings were close to a pancreatic hamartoma that consisted of sparsely distributed pancreatic ducts and acini in heavily collagenized fibrous stroma. Neither islet nor peripheral nerve existed in the tumor. The fibroblastic cells in the stroma were immune-positive for CD34, CD99, and bcl-2. But these expressions were not decisive in the differentiation between solitary fibrous tumor and pancreatic hamartoma, because CD34 was positive for both tumors, and CD99 and bcl-2 expressions were not elucidated in the previous cases of pancreatic hamartomas. Thus, we evaluated NAB2-STAT6 fusion. The fibroblastic cells were positive for STAT6 and sequencing analysis revealed the gene fusion between NAB2 exon 4 and STAT6 exon 2, with which the final diagnos is of solitary fibrous tumor was achieved. In conclusion, detection of NAB2-STAT6 fusion has a great diagnostic value for pancreatic solitary fibrous tumors with hamartoma-like features.

Primary mesenchymal tumors of the pancreas: single-center experience over 16 years

OBJECTIVE

Primary mesenchymal tumors of the pancreas are extremely rare and no comprehensive study of this class of tumors has been previously performed.

METHODS

Twenty cases of the primary mesenchymal tumors of the pancreas were selected and compared clinicopathologic variables with consecutively resected 500 pancreatic ductal adenocarcinomas.

RESULTS

Finally, 20 (0.3%) cases were confirmed as primary mesenchymal tumors. The 14 (70%) cases of benign/borderline tumors included 4 cases of fibromatoses, 2 cases of cavernous hemangiomas, 2 cases of schwannomas, 2 cases of solid and cystic hamartomas, 2 cases of solitary fibrous tumors, 1 case of inflammatory myofibroblastic tumor, and 1 case of angiomyolipoma. The 6 (30%) cases of sarcomas comprised 3 cases of undifferentiated/unclassified sarcomas, 1 case of leiomyosarcoma, 1 case of Ewing sarcoma/primitive neuroectodermal tumor, and 1 case of atypical lipomatous tumor/well-differentiated liposarcoma. When compared with the 500 ductal adenocarcinomas, the 3 surgically resected sarcomas were larger (mean, 5.8 cm vs 3.6 cm; P = 0.02); however, no difference in median survival time was observed between patients with sarcoma (23 months) and patients with ductal adenocarcinoma (16 months).

CONCLUSIONS

First, primary mesenchymal tumors of the pancreas are extremely rare. Second, several primary mesenchymal tumor types can be observed in the pancreas. Understanding these rare disease entities will help ensure their correct diagnosis.

Nasopharyngeal leiomyomatous hamartoma: case report

Background

Fibroma, neurofibroma, and papilloma are the most commonly encountered benign lesions in the nasopharynx. Hamartomas are non-neoplastic overgrowth of mature/differentiated tissue indigenous to the specific part of the body in which they develop. Most hamartomas are located in the liver, spleen, lungs, and pancreas. However, nasopharyngeal hamartoma is rare.

Case presentation

We describe here a 77-year-old Japanese woman who presented with a mass arising from the left lateral wall of the nasopharynx. Computed tomography (CT) revealed a soft tissue mass without bony erosion, suggesting that the mass was a benign tumor such as a fibroma. Pathological examination showed that the mass was a leiomyomatous hamartoma.

Conclusion

To our knowledge, this is the first report of a leiomyomatous hamartoma in the nasopharynx. Although leiomyomatous hamartoma in the nasopharynx is extremely rare, it should be kept in mind during differential diagnosis.