1. Clinical case T. Guarneri
Cattedra di radiologia – Università di Brescia 1

2. Physiological anamnesis:
D.F. 20 ys, F
Physiological anamnesis:
Good general health conditions
Close pathologic anamnesis: On May 2011 she has a car accident 2

3. Chest XR ( )
NEGATIVE?

4. 27.05.2011: abdominal pain, no fever or other symptoms
Ultrasound

5. Heterogeneously hypoechoic mass (52 x 25 mm) in the paraspinal and presacral regions
ADENOPATHY?

6. CT ( )

7. Chest

8. .
Abdomen

9. Neurofibromatosis Type 1 (von Recklinghausen disease)
- one of the most common genetic disorders (prevalence: 1:3000)
- mutation of the NF1 gene (chromosome 17): no control of cellular proliferation
50% positive family history
50% sporadic new mutations

10. Diagnostic Criteria for NF1
The patient should have two or more of the following:
1. Six or more cafe´ au lait spots
1.5 cm or larger in postpubertal individuals
0.5 cm or larger in prepubertal individuals
2. Two or more neurofibromas of any type or one
or more plexiform neurofibromas
3. Freckling in the axilla or groin
4. Optic gliomas (tumor of the optic pathway)
5. Two or more Lisch nodules (benign hamartomas)
6. A distinctive bony lesion
Dysplasia of the sphenoid bone
Dysplasia or thinning of long bone cortex
7. First degree relative with NF1

11. Classification of Abdominal Neoplasms in NF1
● Neurogenic neoplasms
Neurofibroma
Plexiform neurofibroma
Malignant peripheral nerve sheath tumor
Ganglioneuroma
● Neuroendocrine neoplasms
Carcinoid
Pheochromocytoma
Paraganglioma / Gangliocytic paraganglioma
● Non neurogenic gastrointestinal mesenchymal neoplasms
Gastrointestinal stromal tumor
Leiomyoma / Leiomyosarcoma
● Embryonal tumors
Rhabdomyosarcoma
Neuroblastoma
Wilms tumor
● Miscellaneous tumors
Gastrointestinal adenocarcinoma
Pancreatic adenocarcinoma
Biliary adenocarcinoma
The lifetime risk of developing an MPNST (malignant peripheral nerve sheath tumor) for a person with NF1 is 4-5%.

12. Neurofibromas are the hallmark lesion of NF1
65% asymptomatic
35% symptomatic:
- palpable abdominal mass
- pain along the distribuition of the nerve
- GI mucosal involvement (hematemesis, melena, hematochezia)
- intestinal obstruction (nausea, vomiting,abdominal distension)
-bladder involvement (urinary frequency, incontinence, urgency, abdominal pain)

13. Radiologic features
In the thorax, neurofibromas tipically appear as well-marginated, smooth, round or elliptic masses in the paravertebral regions or along the course of the vagus, phrenic, recurrent laryngeal or intercostal nerves.
Plexiform neurofibromas are extensive fusiform or infiltrating masses that tend to surround mediastinal vessels with loss of normally visible fat planes.
In the abdomen, neurofibromas are located in the paraspinal (symmetric or asymmetric masses within or adjacent to the psoas muscle) and presacral regions, along the course of the lumbosacral plexus.
Mesenteric plexiform neurofibromas manifest as multiple nodules or infiltrating lesions of the wall of the intestine.
The lesions in the perirectal region can infiltrate the perirectal fat and the pelvic structures.

14. US: heterogeneous in echotexture with variable through transmission (e
US: heterogeneous in echotexture with variable through transmission (e.g. retroperitoneal and paraspinal neurofibromas), homogeneously or heterogeneously hypoechoic in echotexture (e.g. mesenteric neurofibromas)
CT: neurofibromas are iso- or hypoattenuating masses, compared with adjacent soft tissue (20-25 HU on nonhenanced scans, HU on intravenous contrast –enhanced scans). They have variable contrast enhancement and may calcify.
MR: low signal intensity on T1-weighted images heterogeneous high signal intensity on T2-weighted images  corresponds to areas of cystic degeneration or myxoid matrix

15. MR T1 T2

16. NF1: a diagnostic mimicker at CT
● Lymphoma
● Tuberculosis
● Infection (Mycobacterium avium-intracellulare complex)
● Sarcoidosis

17. ● Esophageal cancer
● Invasive thymoma
● Fibrous pleural tumors
● Metastatic pleural implants
● Extramedullary hematopoiesis

18. ● Pancoast tumor
● Solitary pulmonary nodule

19. ● Pulmonary adenocarcinoma
● Metastatic adenocarcinoma
● Plasmacytoma
● Pulmonary infection (nocardiosis, actinomycosis)
● Metastatic disease
● Soft-tissue sarcoma
● Chondrosarcoma

20. ● Vertebral metastatic disease
● Myeloma
● Tuberculous spondylitis
● Bilateral adrenal masses

21. ● Celiac adenopathy
● Retrocrural adenopathy

22. ● Psoas abscess
● Rectal inflammatory or malignancy

23. ● Iliac and obturator adenopathy

24. ● Primary bone malignancies (giant cell tumor, chordoma, lymphoma) or metastasis
● Primary or metastatic soft-tissue sarcoma

25. Treatment
● Imaging studies are indicated only when patients are symptomatic.
● Surgery is currently the only treatment option for most of the lesions in NF1.
● Chemotherapy and radiation therapy are recommended only for the treatment of the malignant tumors.

26. Bibliography
● Fortman BJ, Kuszyk BS, Urban BA, Fishman EK, “Neurofibromatosis Type 1: A Diagnostic Mimicker at CT”. RadioGraphics 2001; 21:
● Biondetti PR, Vigo M, Flore D, et al. “CT appearance of generalized von Recklinghausen neurofibromatosis”. J Comput Assist Tomogr 1983; 7:866–869.
● Levy AD, Patel N, Dow N, Abbott RM, Miettinen M, Sobin LH, “From the Archives of the AFIP:Abdominal Neoplasms in Patients with Neurofibromatosis Type 1: Radiologic-Pathologic Correlation”. RadioGraphics 2005; 25:455–480.
● Braunwald e, Fauci AS, Kasper DL,Hauser SL, Longo DL, Jameson JL, “Harrison: Principi di Medicina Interna”. Ed. McGraw-Hill 2002.
● Tonsgard JH, “Clinical Manifestations and Management of Neurofibromatosis Type 1” Semin Pediatr Neurol 2006; 13:2-7