GIST associated with von recklinghausen disease: Report of two cases and review of literature

Giant lipoma of the colon presenting as a case of adult intussusception: A case series

INTRODUCTION AND IMPORTANCE

Lipoma of the intestine is one of the uncommon benign tumors of the alimentary tract first reported by Bauer in 1957. The peak incidence is usually seen between 50 and 60 years of age and more commonly in females. They are usually either asymptomatic or mildly symptomatic. The occurrence of symptoms is mostly related to the diameter of the lesion.

PRESENTATION OF CASE

We present a single center consecutive case of three patients who had giant colonic lipomas presented with colonic intussusception. Two of the cases presented for the first time with an emergency condition: acute intestinal obstruction. The mode of presentation, diagnosis, and management outcome of colonic lipoma was assessed.

DISCUSSION

Symptomatic lipoma may present with non-specific abdominal pain, change in bowel habits, intussusception, and hemorrhage. The clinical diagnosis is usually challenging, given the non-specificity of symptoms of the disease. Computed tomography is considered to be a diagnostic modality of choice in recognizing the presence of lipoma. However, a definitive diagnosis of lipoma is usually obtained after a histopathologic examination of the resected specimen. The management of colonic lipoma depends on the size of the lesion and the presence or absence of symptoms.

CONCLUSION

Colonic lipoma is a rare benign tumor that occurs in the elderly, frequently misdiagnosed as a malignant tumor. Despite the rarity of the disease, lipoma should be considered in the differential diagnosis of large bowel tumors and adult intussusception.

Unusual presentation of GIST associated with type 1 neurofibromatosis: A case report

INTRODUCTION AND IMPORTANCE

Type 1 neurofibromatosis (NF1) is an autosomal dominant disorder caused by NF1 gene mutation, which is associated with several types of tumors. GIST is an intestinal stromal tumor arising from interstitial cells of Cajal in the intestine. GIST is one of the neoplasms seen in NF1 and usually affects elderly individuals with a median age around 60-65 years but rarely occur in children, adolescent and young adults.

CASE PRESENTATION

An 18-year-old male patient presented to our hospital with abdominal swelling of one-year duration. He also has multiple skin nodules and café au lait spots all over his body. Objectively, the abdomen is grossly distended; with a palpable non-tender mobile mass above the umbilicus measuring 20 × 15 cm. CT imaging of the abdomen and histologic examination of the skin lesion was done. The diagnosis of GIST was made and surgical resection followed by adjuvant therapy with imatinib was given.

CLINICAL DISCUSSION

Patients who have a gene mutation in NF 1 have a high probability (7 %) of developing GIST and mostly occur in the small intestine, whereas our finding was solitary GIST localized to the stomach. NF 1-associated GISTs are very rare and account for <5 % of all GISTs. The standard therapy for GIST is surgical resection of the tumor. Targeted therapy with tyrosine kinase inhibitors is an effective adjuvant therapy in patients harboring KIT/PDGFRA mutation.

CONCLUSION

The incidence of GIST is higher in NF1 patients than in the general population. The definitive diagnosis of GISTs preoperatively is usually challenging and is usually confirmed by immunohistochemistry. NF1-associated GISTs are mainly treated with surgery and have limited response to tyrosine kinase inhibitors.

Genetic susceptibility in children, adolescents, and young adults diagnosed with soft-tissue sarcomas

Soft tissue sarcomas (STS) may arise as a consequence of germline variants in cancer predisposition genes (CPGs). We believe that elucidating germline sarcoma predisposition is critical for understanding disease biology and therapeutic requirements. Participation in surveillance programs may allow for early tumor detection, early initiation of therapy and, ultimately, better outcomes. Among children, adolescents, and adults diagnosed with soft-tissue sarcomas and examined as part of published germline sequencing studies, pathogenic/likely pathogenic (P/LP) variants in CPGs were reported in 7-33% of patients. P/LP germline variants were detected most frequently in TP53, NF1 and BRCA1/2. In this review, we describe reported associations between soft tissue sarcomas and germline variants in CPGs, with mentioning of locally aggressive and benign soft tissue tumors that have important associations with cancer predisposition syndromes. We also discuss recommendations for diagnostic germline genetic testing. Testing for sarcoma-predisposing germline variants should be considered as part of the routine clinical workup and care of any child, adolescent, or adult diagnosed with STS and take into account consequences for the whole family.

Multiple Small Bowel Gastrointestinal Stromal Tumors Associated with Neurofibromatosis Type 1 that Were Not Detected by Endoscopy: A Case Report

We treated a 39-year-old Japanese man who was admitted for an abdominal mass. He had had neurofibroma-like skin lesions since childhood. Computed tomography and endoscopic ultrasound results were consistent with a tumor in the small intestine. Although the tumor was undetectable by single-balloon endoscopy, the patient's background and imaging results led us to suspect a gastrointestinal stromal tumor (GIST). He also met the diagnostic criteria for neurofibroma type 1 (NF1). We performed a surgical removal of the tumor, and the biopsy results led to a definitive diagnosis of GIST. Small bowel GISTs should be considered in cases of NF1.

Clinical presentation and genetic analyses of neurofibromatosis type 1 in independent patients with monoallelic double de novo closely spaced mutations in the NF1 gene

Neurofibromatosis type 1 (NF1) belongs to RASopathies, a group of syndromes caused by germline mutations in Ras/MAPK pathway genes. Most NF1 patients exhibit single inactivating pathogenic variants within the NF1 gene. We performed extensive genetic analyses in two NF1 families disclosing the first two cases of double de novo monoallelic NF1 variants. Both index patients described in this study had classical NF1. Probands were born from fathers in their late 30s and presented closely spaced double mutations (<100 bp) in NF1 regions showing an excess of somatic mutations. Closely spaced multiple mutations have been reported in RAS/MAPK signaling genes but never in NF1. Mutagenesis is a quasi-random process in humans, therefore two causative variants in the same gene, moreover in the same allele are exceptional. Here, we discuss possible mechanisms for this ultrarare event. Our findings confirm the possibility of a higher risk of concurrent de novo variants in NF1.

A Rare Case of Multiple Gastrointestinal Stromal Tumors Coexisting with a Rectal Adenocarcinoma in a Patient with Attenuated Familial Adenomatous Polyposis Syndrome and a Mini Review of the Literature

Background: Multiple gastrointestinal stromal tumors (GISTs) are extremely rare entities that exist either as spontaneous GISTs or as part of various syndromes, such as Carney’s triad and type I neurofibromatosis (NF1). Attenuated familial adenomatous polyposis (AFAP) is a variant of familial adenomatous polyposis (FAP) with a milder clinical presentation. Both GISTs and AFAP have been reported to coexist with colorectal cancer, but the coexistence of GISTs and AFAP has never been reported in the literature before. Case report: A 45-year-old male patient with known AFAP arrived scheduled for a total colectomy and ileo-rectal anastomosis due to the malignancy of one of the previously biopsied polyps of the upper rectum. Intraoperatively, multiple nodular tumors were found at the jejunum within a length of 45 cm, for which an enterectomy and enteroanastomosis were performed. A histopathological examination of the whole colectomy specimen confirmed the presence of multiple polyps in the large intestine along with a rectal invasive adenocarcinoma. At the same time, in the examined part of the small intestine, 15 GISTs sized from 0.5 to 2.0 cm of prognostic group I, were identified. The patient’s postoperative course was uncomplicated. Conclusion: Multiple GISTs may present as an asymptomatic disease, and the same thing is true for colorectal cancer. Therefore, the appropriate screening is crucial for entities such as AFAP, since the surgery was performed because of the malignant transformation in one of the polyps and revealed multiple GISTs, as well.