Rare triad of periampullary carcinoid, duodenal gastrointestinal stromal tumor and plexiform neurofibroma at hepatic hilum in neurofibromatosis type 1: a case report

Mucinous Adenocarcinoma and Carcinoid Tumor Arising Within an Ovarian Mature Cystic Teratoma: A Case Report

The coexistence of both mucinous adenocarcinoma and carcinoid tumor within an ovarian mature cystic teratoma is extremely rare. We report a case of an 18-year-old Omani woman with a left ovarian cyst. After laparotomy with left salpingo-oophorectomy, omentectomy, and peritoneal washings, the excised cyst had the typical morphology of mature cystic teratoma with grade I mucinous adenocarcinoma and a focus of carcinoid tumor.

The GIST of It: A Rare Presentation of Neurofibromatosis Type I

Neurofibromatosis-1 (NF-1) is an autosomal dominant condition characterized by cutaneous pigmentation and tumour formation along nerves in the brain, skin, and other organs. Gastrointestinal stromal tumours (GIST) are rare mesenchymal tumours involving the gastrointestinal tract (GI) associated with NF-1. We present a case of life-threatening GI bleeding from GIST in a patient with NF-1. In NF-1 patients presenting with GI bleeding, GISTs should be part of the differential. Clinicians must have a low threshold for urgent abdominal imaging if endoscopy does not detect the source of GI bleeding.

A rare case of plexiform neurofibroma of the liver in a patient without neurofibromatosis type 1

Plexiform neurofibroma is mainly associated with neurofibromatosis type 1 and is seldom observed in the liver. Its occurrence in the liver without neurofibromatosis type 1 is even rarer. We report an extremely rare case of plexiform neurofibroma of the liver diagnosed by laparoscopic biopsy in a patient without neurofibromatosis type 1. The patient was a 35-year-old man who had neither clinical signs nor any family history of neurofibromatosis type 1. Abdominal ultrasonography, as part of a health screening, had detected a hepatic tumor. Subsequent contrast ultrasonography, computed tomography, and magnetic resonance imaging showed the tumor extending from the retroperitoneal space around the aorta to the hepatic hilum and distal portal branches in the right hepatic lobe, gallbladder, and left hepatic lobe. ¹⁸F-fluorodeoxyglucose positron emission tomography showed no abnormal accumulation. Histopathological examination of the tumor obtained laparoscopically led to a diagnosis of plexiform neurofibroma. Because the patient was asymptomatic with no features of malignancy, he was only monitored and managed. At follow-up 10 years later, computed tomography showed a decrease in tumor size. It is important to recognize that, while rare, plexiform neurofibroma can occur without neurofibromatosis type 1. We recommend follow-up instead of unreasonable surgery in such cases.

Advanced pharmacological therapies for neurofibromatosis type 1-related tumors

Neurofibromatosis Type 1 (NF1) is an autosomal dominant tumor-predisposition disorder that is caused by a heterozygous loss of function variant in the NF1 gene, which encodes a protein called neurofibromin. The absence of neurofibromin causes increased activity in the Rat sarcoma protein (RAS) signalling pathway, which results in an increased growth and cell proliferation. As a result, both oncological and non-oncological comorbidities contribute to a high morbidity and mortality in these patients. Optic pathways gliomas, plexiform neurofibromas and malignant peripheral nerve sheath tumor (MPNST) are the most frequent NF1-associated tumors. The treatment of these complications is often challenging, since surgery may not be feasible due to the location, size, and infiltrative nature of these tumors, and standard chemotherapy or radiotherapy are burdened by significant toxicity and risk for secondary malignancies. For these reasons, following the novel discoveries of the pathophysiological mechanisms that lead to cell proliferation and tumorigenesis in NF1 patients, emerging drugs targeting specific signalling pathways (i.e. the MEK/ERK cascade), have been developed with promising results.

KIT and platelet-derived growth factor receptor α wild-type gastrointestinal stromal tumor associated with neurofibromatosis type 1: Two case reports

BACKGROUND

Gastrointestinal stromal tumors (GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1 (NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.

CASE SUMMARY

A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT (CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600E mutation. The patients were alive and well during the follow-up period (range: 0.6-5 yr).

CONCLUSION

There have been only a few previous reports of GISTs associated with NF-1. Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence, genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intra-abdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities. Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.

Spectrum of gastrointestinal lesions of neurofibromatosis type 1: a pictorial review

Abstract

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders. Gastrointestinal manifestations of NF-1 are seldom thought of in routine clinical practice and might thus be significantly under-recognised. Their heterogeneous spectrum ranges from localised microscopic proliferative lesions to grossly recognizable mass-forming neurofibromas, neuroendocrine and gastrointestinal stromal tumours (GIST). The aim of this study is discussing the imaging evaluation and characterisation of the abdomen lesions in patients with NF1.

Teaching Points

• Neurofibromatosis type (NF-1) is one of the most common single gene disorders.

• Every organ system can be involved and intra-abdominal manifestations are underestimated.

• The NF1 abdominal manifestations comprehend five categories of tumours.

• Neurogenic tumours including with neurofibromas are the most common type.

• Early diagnosis of abdominal manifestations of NF-1 based on imaging patterns is necessary for appropriate treatment to avoid serious organic complications related to tumour mass.

Intraductal papillary bile duct adenocarcinoma and gastrointestinal stromal tumor in a case of neurofibromatosis type 1

We report our experience with a synchronous case of gastrointestinal stromal tumor (GIST) and intraductal papillary neoplasm of the bile duct (IPNB) in an elderly woman with neurofibromatosis type 1 (NF-1). A 72-year-old woman presented with a 2-mo history of right upper abdominal pain unrelated to diet and indigestion. Fourteen years earlier, she had been diagnosed with NF-1, which manifested as café au lait spots and multiple nodules on the skin. Computed tomography (CT) revealed a multilocular low-density mass with septation, and mural nodules in the right hepatic lobe, as well as a 1.7-cm-sized well-demarcated enhancing mass in the third portion of the duodenum. The patient subsequently underwent right hepatectomy and duodenal wedge resection. We present here the first report of a case involving a synchronous IPNB and GIST in a patient with NF-1. Our findings demonstrate the possibility of various tumors in NF-1 patients and the importance of diagnosis at an early stage