Neurofibromas are benign peripheral nerve sheath tumors that are the most common manifestation of neurofibromatosis type 1 (NF1). They typically present in young adults as slow-growing, solitary masses under 5cm located on superficial cutaneous nerves of the head and neck. Neurofibromas associated with NF1 can be diffuse, involving long nerve segments beyond the epineurium. Imaging shows well-defined hypodense masses on CT without enhancement, and hyperintense lesions on T2-weighted MRI with heterogeneous enhancement. Lipomas are benign fatty tumors that most commonly involve the long bones, presenting as osteolytic lesions on plain films.

2.  NEUROFIBROMAS
 NEUROFIBROMATOSIS

3.  Benign peripheral nerve sheath tumours.
 Peak age......... 20-30yrs
 No sex predilection
 3 types
 Localized
 Diffuse
 Plexiform

4.  Most common, 90%
 Solitary, not associated with NF 1
 Affects superficial cutaneous nerves
 Slow growing
 <5cm in size at presentation

6.  Children, young adults.
 Solitary, not associated with NF 1.
 Located within s/c tissue of head & neck.
 Cause plaque like elevation of skin with
thickening of entire sub cutis.

8.  Diffuse involvement of long nerve segment
and its branches, extending beyond
epineurium into surrounding tissue
 Pathognomic of NF 1
 Early childhood
 Malignant transformation

9. Neurofibroma arising in the obturator ring has caused
considerable pressure erosion of both right pubic rami,
particularly the superior one. The margins of the pressure defect
are sharply defined.

10. Two large ovoid neurofibromas (arrows) are shown as
filling defects within the thecal sac at the L4/5 level

11.  Majority solitary
 Neurofibromatosis
 Multiple neurofibromas...diagnostic of NF 1

12.  CT
 Well defined, hypodense mass
 Little or no contrast enhancement

13. Multiple paravertebral neurofibromas which are hypodense,
well defined and enlarge neural foramina

14. ct shows contrast enhancing soft tissue mass parietal and
occipital on the left side. Bone window images show destruction
and deformity of the occipital bone due to biopsy proven
neurofibroma

15.  MRI
 T1: hypointense
 T2: hyperintense
▪ Target sign
 T1 post contrast: heterogeneous enhancement
PLEXIFORM: large lobulated and conglumerated
masses extending along nerves and its branches

16. T1w axial through cervical spine shows a low signal intensity mass
extruding through right foraminal canal at c5-c6 level, eroding the
vertebral body.

17. T2w hyperintense neurofibroma

18.  Multisystem neurocutaneous disorder
 Most common phakomatosis
 Most common inherited CNS disorder,
autosomal dominated disorder
 1:3000, M=F
 50% inherited, 50% spontaneous

19.  >6 cafe au lait spots
 Neurofibromas
 2 cutaneous or
 2 subcutaeous or
 2 nodular or
 1 plexiform
 Optic nerve glioma
 Distinctive osseous lesions
 Sphenoid wing dysplasia
 Two or more iris hamartomas (Lisch nodules)
 Axillary or inguinal freckling
 Primary relative with NF1

21. Cutaneous neurofibromata

22. Subcutaneous neurofibroma

23. Optic nerve glioma Soft tissue density lobulated lesion
encasing the left optic nerve

24. Plain radiograph of forearm of 15 yr old boy shows hypoplasia and
deformity of radius and ulna. intramedullary sclerotic streaks in radius and
periosteal deformity

25. sphenoid wing dysplasia ,t2

28. NF1 gene locus is on 17q11.2 and the gene
product is neurofibromin, act as a tumour
suppressor.
Tumour is primarily a hamartomatus disorder
involving ectoderm and mesoderm

29.  Kyphoscoliosis
 Posterior vertebral scalloping
 Posterior hypoplastic elements
 Enlarged neural foramina
 Ribbon rib deformity, rib notching, dysplasia
 Dural ectasia
 Tibial pseudoarthrosis, bony dysplasia affecting
tibia
 Severe bowing
 Multiple NOF
 Limb hemihypertrophy

30. Kyphoscoliosis Combination of outward curvature
and lateral curvature

31. Posterior vertebra scalloping

32. Ribbon ribs

33. Sagittal T1WI unenhanced scan in a28 yr old women shows dural
ectasia and a large lobulated anterior sacral meningocele.

34. Pseudarthroses of the tibia and fibula shown in an infant. Bowing
of bone and absence of any evidence of bone repair are typical.

35. Axial sonogram through right iliac fossa in 28 YR OLD
man with nf1 shows a dumbbell shape neurofibroma

36. solitary neurofibroma displacing the femoral vessels there is clear
mesenchymal dysplasia, with extensive abnormalities of subcutaneous tissue
and hemihypertrophy.

37.  CNS: dysplasias,hamartomas,neoplasms
 OCCULAR: buphthalmos
 GI: carcinoid tumor
 ENDOCRINE: pheocromocytoma
 GU: wilms tumor
 PULMONARY: interstitial fibrosis

38.  Rare autosomal dominant neurocutaneous
disorder
 Not associated with neurofibromas

39.  MISME
 Multiple inherited schwannomas
 Meningioma
 Ependymoma

41.  LIPOMA
 INTRAOSSEOUS
 PARAOSTEAL
 LIPOSARCOMA

42.  Rare bone lesion
 Most common lipogenic tumor in bone
 4-5th
decade of life
 Slight male predilection

43.  PAIN
 Anywhere in the skeleton
 Long bones..........metaphysis, medullary
cavity

44. o Lower limb 71%
o Calcaneum 32%
o Femur 20%
o Tibia 13%
o Fibula 6%
o Upper limb 7%
o Skull, mandible 7%
o Spine and pelvis 12%
o Ribs 2.5%

45.  PLAIN FILM
 Osteolytic
 Well defined margins

46. intraosseous lipoma within the calcaneum

48. 3 CATEGORIES
• TYPE 1: sharply delineated, viable lipomas,
homogenous fat content
Homogenous hyperintense fat signal on T1 and
T2WI, suppressed by STIR

50. • TYPE 2: predominantly fatty lesions with central
necrosis, calcifications or ossifications
 Hypointense inclusions on T1WI which may appear
hyperintense on STIR(granulation tissue) or
hypointese( calcifications or ossifications)

53. • TYPE 3: heterogeneous, fat containing lesions with
necrosis, cystic transformation, wall sclerosis,
extensive calcifications or ossifications.
 Fluid equivalent cavities, signal void bony septae,
surrounded by signal void rim of sclerotic bone.

54. Intraosseous lipoma with cystic transformation

56. CALCANEAL CYST

57.  Rare benign tumour associated with
periosteum
 0.3% of lipomas

58.  Slow growing, painless, immobile mass, not
fixed to skin
 Nerve compression with forearm lesions
 Firmly adherent to underlying cortex
 Femur, proximal radius

59.  PLAIN FILM
 Bowing of bone or cortical erosion

60. Parosteal lipoma .A discrete tumour arises from the interosseous
membrane of the forearm

61.  CT
 Septations
 Prominent osseous protuberance
 Mild enhancement in fibrous tissue

62.  MRI
 Juxtacortical heterogeneous lobulated sepated
mass with signal intensity similar to subcutaneous
fat.
 Adjacent muscle atrophy is better seen on T2

63. Axial t1wi showing a high signal intensity mass arising from surface
of humerus and bulging from beneath the deltoid muscle with low
signal exophytic mass arising from humerus

64.  BONE SCINTIGRAPHY
 Increased uptake

65.  PARAOSTEAL LIPOSRACOMA
 Soft tissue fails to contain fatty lucencies
 INTRAOSSEOUS LIPOSARCOMA
 Ill-defined lytic lesion
 Femur, tibia
 Vascular
 Rapid extension into soft tissue
 Early pulmonary metastasis