Surgical Management of Abdominal Manifestations of Type 1 Neurofibromatosis: Experience of a Single Center

Abstract

Neurofibromatosis type 1 (NF1) is a genetic disease characterized by neoplastic and nonneoplastic disorders involving tissues of neuroectodermal and mesenchymal origin. The mainly involved districts are skin, the central nervous system, and eye and there is a wide range of severity of clinical presentations. Abdominal manifestations of NF1 include five kinds of tumors: neurogenic tumors (neurofibromas, malignant peripheral nerve sheath tumors [MPNSTs], and ganglioneuromas); neuroendocrine tumors (pheochromocytomas and carcinoids); nonneurogenic gastrointestinal stromal tumors (GISTs); embryonal tumors; and miscellaneous. The present experience depends on the participation in the National Project for Diagnosis and Treatment of Rare Diseases. In the group of patients with a diagnosis of von Recklinghausen disease, 10 patients underwent surgical treatment for gastrointestinal and retroperitoneal tumors associated with NF1. Three patients underwent adrenalectomy for pheochromocytoma (in one case associated with jejunal wall neurofibroma); two patients were found to be affected by MPNST (recurrent and unresectable in one case). One patient was affected by giant gastric GIST and jejunal neurofibroma; two patients were affected by extraperitoneal neurofibroma (pararenal and pararectal position); one patient was affected by giant colic neurofibroma and one patient was affected by retroperitoneal bilateral plexiform neurofibromas. Early diagnosis of these abdominal manifestations is very important because of the risk of malignancy, organic complications (such as pheochromocytoma), or hemorrhagic–obstructive complications such as in case of tumors of the gastrointestinal tract (GISTs and neurofibromas). The importance of an annual clinical evaluation on the part of a multidisciplinary pool of clinicians in highly specialized centers allows early detection of complications and of neoplastic transformation. Genetic screening allows preclinical diagnosis with a sensibility of 95 per cent. Further studies are necessary to detect predictive factors of malignant tumor development of severe clinical conditions.

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

“…Early diagnosis of these gastrointestinal manifestations is very important because of the risk of malignancy and organic or haemorrhagic-obstructive complications. The unforeseeable course of NF1 and the lack of a resolute cure lead to the necessity of a strict follow-up managed by an expert multidisciplinary team [ 13 ]. Surgical removal, when technically feasible, prevents local infiltration and malignant transformation [ 22 ].…”

“…Visceral abdominal neoplasms occurring in patients with NF1 fall into five categories of neoplasms, presented in Table 1 [ 7 , 12 ]: neurogenic tumours, neuroendocrine tumours, non-neurogenic gastrointestinal stromal tumours, embryonal tumours and miscellanea. Benign and malignant neoplasms may arise in the abdomen in both paediatric and adult patients with NF1 [ 12 , 13 ].…”

“…Histologically, they are composed of Schwann cells, fibroblasts and myxoid or mucinous matrix surrounded by collagenous tissue with mast cell infiltration and adipocytes, associated with cystic degeneration [ 12 , 13 , 21 ]. It may present as a solitary mass with smooth well-defined margins or a plexiform presentation [ 13 , 21 ]. Malignant transformation is reported in between 5 and 15%, especially in patients of over 40 years of age [ 16 ].…”

“…They are benign nerve sheath tumours usually affecting the head, neck, pelvis and extremities but can be found anywhere in the body [ 23 ]. They tend to grow to large sizes and may cause substantial disfigurement [ 12 , 13 ]. Plexiform neurofibromas are seen exclusively in NF1; they are thought to be congenital and usually manifest early in life with an incidence of 15–30% [ 19 , 22 ].…”

Nonoperative Management May Be a Viable Approach to Plexiform Neurofibroma of the Porta Hepatis in Patients with Neurofibromatosis-1

“…It was reported that the prevalence of intrahepatic lesions was 2.3% of all PNFs involving the abdomen and pelvis [ 18 ]. Only a few cases of patients with intra-abdominal PNFs have been reported in the literature [ 22 , 31 , 32 ]. We encountered a challenging case of PNF involving the PH in the clinic and this prompted us to report our findings and review the literature on this rare but complex clinical entity.…”