GENERALIZED MOSAIC NEUROFIBROMATOSIS TYPE 1 : A RARE CASE REPORT Affiliation

Neurofibromatosis (NF) consists of group of gene cally inherited disorders all of which is characterized by occurrence of nerve sheath tumors. There are eight different subtypes of neurofibromatosis. Segmental NF, a rare mosaic pa ern of NFtype1 (NF1) is diagnosed in individuals who have typical features of NF1 restricted to one part of the body and whose parents are both unaffected. But recently the nomenclature has been changed to mosaic NF.


INTRODUCTION
Neurofibromatosis(NF) consists of group of gene cally inherited disorders all of which is characterized by occurrence of nerve sheath tumors.The mode of inheritance is autosomal dominant with a high rate of new unaffected.The presenta on can be limited to a narrow strip of one quadrant to occasionally to whole half of the 7 body.
Here, we report a case of 52 years old male who presented with freckling, mul ple len gines, café-au-lait macules (CALM) and neurofibroma in a blaschkoid pa ern bilaterally, which to our knowledge has not been reported ll date.

CASE REPORT
A 52 years old male came to dermatology out-pa ent department with Tinea cruris.But, on further examina on for signs of fungal infec on elsewhere, mul plecafé-au-lait macules and freckles along with len gines were noted.
On further ques oning, pa ent men oned a few grouped so nodules over the right abdomen.Pa ent was not exactly sure but claimed that both the pigmentary changes and the nodules were present for more than 25 years.
There was no history of similar skin lesion in other family members.No history of any bony abnormali es or seizures.Pa ent was literate but was not able to complete high school because of family problems.He was an overseas foreign worker currently placed in middle east.
No major illness or surgeries were noted in the past.
On examina on, there were mul ple len gines and freckles following a pa ern extending from the forearm, involving the axilla bilaterally and converging in the mid-abdomen.(Figure 1a)Similarly grouped len gines following a linear pa ern was also noted in the back.(Figure 1b).Mul ple freckles were also noted in the axilla bilaterally.(figure 2)  There were mul ple cafe-an-lait macules (CALMs), many of them greater than 1.5cm each.(Figure 2) Mul ple so skin colored nodules were noted on right side of chest and abdomen.(Figure 3) The nodules were so in consistency, mobile and demonstrated "bu on-hole" sign.The presence of axillary freckling and mul ple CALMs made 4 us label the case as NF 1, as per the diagnos c criteria.But from the presence of the freckles and CALMs along with the so tumors in a blasckoid pa ern, we made the diagnosis of generalized mosaic neurofibromatosis.
Pa ent was explained on the course and prognosis of the disease and was advised for regular follow-up.

DISCUSSION
Neurofibromatosis is classified into eight subtypes.Among before ssue differen a on causes generalized disease.
But a er recogni on of the soma c muta on involved in these subtype, recent sugges on is to use correct term as 10 "mosaic" NF rather than type V or segmental.In 2001, Ruggieri and Huson divided neurofibromatosis with soma c muta on into 2 dis nct subsets mosaic localized and mosaic generalized based specifically on the me of 7 muta on.
A systemic review of 320 individuals with segmental neurofibromatosis found out that most of pa ents (80%) had unilateral findings and only 20% of pa ents had bilateral findings.But s ll there was no report on bilateral 10 symmetrical blaschkoid pa ern of distribu on.Similarly, other case reports s ll did not men on on this unique pa ern of distribu on.
This case is unique in that the lesion seems to be following the lines of blaschko symmetrically.There is no family history of neurofibromatosis.The nodules showing bu onhole sign were very sugges ve of neurofibroma.
To our best of knowledge, this is the first of the such case report which fits the subtype of generalized mosaic NF following the lines of blaschko bilaterally.

LIMITATION OF THE STUDY
A skin biopsy which is diagnos c of neurofibroma could not be done.An ultrasound of abdomen and pelvis as well as a chest x-ray could have shown any internal organ involvement which was also not done because pa ent did not agree for any inves ga on.

CONCLUSION
Mosaic generalized neurofibromatosis is a rare variant.It should be suspected in cases which presents with unusual presenta on of neurofibromas.A be er nomenclature of mosaic neurofibromatosis should be encouraged over the previously used segmental neurofibromatosis.

CONFLICT OF INTEREST
none

1 muta
on and variable expression.There are eight 2 different subtypes of neurofibromatosis.The prevalence 3 of neurofibromatosis type 1(NF1) is about 1 in 3000.The diagnosis of NF 1 is based on presence of ≥ 2 features out of 4 the seven criteria.It is caused by heterozygous muta ons 5 of the NF1 gene located in chromosome 17q11.2.Segmental neurofibromatosis is a rare mosaic pa ern of NF1 which presents with typical features of NF1 restricted to one part of the body and whose parents are both 6,7

Figure 1a and 1b :
Figure 1a and 1b: Mul ple len ginesand freckles in the bhaschkoid pa ern over the trunk)