LGCmain
Indian Journal of Pathology and Microbiology
Home About us Instructions Submission Subscribe Advertise Contact e-Alerts Ahead Of Print Login 
Users Online: 947
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size
IJPM is coming out with a Special issue on "Genitourinary & Gynecological pathology including Breast". Please submit your articles for these issues


 
  Table of Contents    
CASE REPORT  
Year : 2016  |  Volume : 59  |  Issue : 1  |  Page : 96-98
Lipofibromatous hamartoma of the digital branches of the median nerve presenting as carpal tunnel syndrome: A rare case report with review of the literature


Department of Pathology, Rohilkhand Medical College and Hospital, Bareilly, Uttar Pradesh, India

Click here for correspondence address and email

Date of Web Publication9-Mar-2016
 

   Abstract 

Lipofibromatous hamartoma (LFH) is a rare, benign fibrofatty tumor composed of a proliferation of mature adipocytes within peripheral nerves, which form a palpable neurogenic mass. It affects the median nerve in 66-80% of cases, causing pain and sensory and motor deficits in the affected nerve distribution. Patients typically present with gradually enlarging nontender lesions in the distribution of the affected nerve. The lesion is also seen to be associated with macrodactyly. The pathophysiology of LFH is unknown. Treatment of LFH is based on symptoms of the condition. Histopathology is characteristic. We present a case of young male diagnosed as lipofibromatous hamartoma of the median nerve involving the right index finger. The case is presented due to its rarity.

Keywords: Index finger, lipofibromatous hamartoma, macrodactyly, median nerve

How to cite this article:
Agrawal R, Garg C, Agarwal A, Kumar P. Lipofibromatous hamartoma of the digital branches of the median nerve presenting as carpal tunnel syndrome: A rare case report with review of the literature. Indian J Pathol Microbiol 2016;59:96-8

How to cite this URL:
Agrawal R, Garg C, Agarwal A, Kumar P. Lipofibromatous hamartoma of the digital branches of the median nerve presenting as carpal tunnel syndrome: A rare case report with review of the literature. Indian J Pathol Microbiol [serial online] 2016 [cited 2019 Nov 22];59:96-8. Available from: http://www.ijpmonline.org/text.asp?2016/59/1/96/178241



   Introduction Top


Lipofibromatous hamartoma (LFH) of the nerve is a rare and benign tumor characterized by proliferation of mature adipocytes within the peripheral nerves resulting in a palpable mass. It affects the median nerve in majority of the cases, causing carpal tunnel syndrome like features. [1],[2] Due to overlapping findings this entity needs to be differentiated from other similar entities. Accurate diagnosis is mandatory for definitive treatment. Only a handful of cases are available in the literature, so the exact treatment pattern is not well documented. The management of the case depends on the clinical presentation. A case of lipofibromatous hamartoma of the digital branches of the median nerve in a young male is presented.


   Case report Top


A male aged 21 years presented with pain in the right index finger for 4 years. According to the patient, he got hurt while playing with a ball and then he developed a swelling of the right index finger. The swelling was progressively increasing and now he developed pain. He even has limited flexion and extension movements of the finger. There was no H/o numbness. His past medical and family histories were insignificant. There was no evidence of macrodactyly.

Examination showed a bulbous swelling of the proximal phalanx of the right index finger. The mass was adhered both to the skin surface as well as the deeper tissues. The sensations were normal. X-Ray showed a soft tissue mass [Figure 1]. Preoperative fine needle aspiration and cytology (FNAC) suggested lipoma. A decompression surgery was performed and the resected specimen was sent for histopathology.
Figure 1: X-ray photograph of the right index finger

Click here to view


Grossly, a linear yellowish-white tissue piece measuring 4 cm in length and firm in consistency was received. Microscopy showed multiple mesenchymal components including blood vessels, adipose tissue, fibrous tissue, and nerve bundles. The adipose tissue was arranged in a lobular pattern separated by fibrous septae. The blood vessels were numerous and small in size. At places, thick walled blood vessels were observed with perivascular fibrous tissue proliferation [Figure 2]. The cut - section of the nerve bundles showed increased perineural thickening. Adipocytes were seen surrounding the nerve bundles [Figure 3]. The diagnosis of neural fibrolipoma or LFH of nerves was thus made. The postoperative period was uneventful. He recovered his motor deficit significantly 2 weeks after surgery.
Figure 2: Thickened blood vessels along with perivascular proliferation of fibrous tissue (H and E ×400)

Click here to view
Figure 3: Nerve bundles with surrounding adipocytes (H and E ×400)

Click here to view



   Discussion Top


LFH was first described in the English literature in 1953. In 1969, Johnson and Bonfiglio coined the term LFH, accurately describing the entity and its relation to carpal tunnel syndrome. Several terms have been used to describe this condition including fibrolipomatous hamartoma, intraneural hamartoma, neural fibrolipomatosis, and neural fibrolipoma. [3] As per the World Health Organization, this entity is described as lipomatosis of the nerves. [4]

Adipocytes are normally present in the perineurium and epineurium. LFH of the nerve is a rare soft tissue tumor, which occurs due to fibro-fatty proliferation within the nerve bundles with massive epineural and perineural fibrosis leading to fusiform enlargement of the nerve. [1],[5] It affects the median nerve in 66-80% of cases, causing pain along with sensory and motor deficits along the distribution of the affected nerve. [1] While there is an unexplained predilection for the median nerve, involvement of the brachial plexus, ulnar, radial, peroneal, plantar, sciatic, and digital nerves have also been reported. [3],[4],[6]

Patients typically present with gradually enlarging nontender lesions in the distribution of the affected nerve. There is numbness and tingling along the volar aspect of the wrist and hand. Motor deficits occur late. LFH may be associated with macrodactyly or macrodystrophia lipomatosa, particularly affecting the index and the middle fingers. [4],[7]

Most cases occur within the first three decades of life, with the mean age of 22.3. There is a 2:1 female to male ratio of cases with macrodactyly and a 1:1 ratio in cases without. [4],[8] Although there have been suggestions of a congenital origin to LFH, the etiology remains unclear. [3],[9] Cases arising after trauma have also been documented. [6] It has been suggested that persistent microtrauma to the median nerve from the carpal ligament or external pressure from a flexor retinaculum can initiate a reactive process which induces this tumor. Traumatic neuromas also share similar pathogenesis, but the only difference is that LFH usually extends beyond the carpal ligament. It has also been suggested that like in neurofibromatosis, a dysgenetic disorder may be responsible. [9]

The differential diagnosis includes ganglion cyst, vascular malformation, traumatic neuroma, schwannoma, neurofibroma, and lipoma. [4],[8] LFH shares considerable gross overlap with neurofibromatosis requiring both radiologic and microscopic investigation for accurate differentiation. The importance of this is apparent as LFH is a benign tumor, whereas neurofibromatosis can progress to frank malignancy. Where LFH displays uniform fatty infiltration, intraneural lipomas show focal fatty masses separated from the individual nerve bundles. There are no known laboratory studies which aid in the diagnosis of LFH. FNAC usually suggests a soft tissue tumor as in the present case. Sonographic studies can support the diagnosis of LFH but have to be supplemented with other diagnostic modalities for confirmation. The magnetic resonance appearance of this condition is unique and pathognomonic. Thickened nerve fascicles embedded in evenly distributed fat appear as serpentine low-intensity structures surrounded by high-intensity signal in both T1- and T2-weighted images giving the coaxial cable-like appearance in the axial plane and spaghetti-like appearance in the coronal planes. [6]

LFH tumors are irregular, yellow masses. Microscopy demonstrates nerve bundles that are entrapped within a fibrofatty-fusiform mass. LFH involves a disorganized overgrowth of the epineurium, perineurium, and endoneurium with fatty infiltration. There is no inflammation or involvement of the surrounding tissues. Lipomatous masses have been divided into four types according to their location within the parent nerve-soft tissue lipoma, intraneural lipoma, macrodystrophia lipomatosa, and LFH. [9]

Treatment of LFH depends on the presenting symptoms. While some cases cause no neurologic or functional complications, others do. Management is usually conservative. [4] In patients presenting as carpal tunnel syndrome, decompression surgery has been shown to provide adequate relief of symptoms. [3],[10] Excision of the nerve is not recommended. Furthermore, extensive intraneural dissection is to be avoided.


   Conclusion Top


Because of the infrequency of the diagnosis, no standard treatment protocol has been established. With more reports of LFH, further insight will be gained into appropriate management modalities.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
   References Top

1.
Silverman TA, Enzinger FM. Fibrolipomatous hamartoma of nerve. A clinicopathologic analysis of 26 cases. Am J Surg Pathol 1985;9:7-14.  Back to cited text no. 1
[PUBMED]    
2.
Sarawagi R, Anderson GA, Cherian RS. Fibrolipomatous hamartoma of the median nerve presenting with carpal tunnel syndrome. Neurol India 2009;57:361-2.  Back to cited text no. 2
[PUBMED]  Medknow Journal  
3.
Nanno M, Sawaizumi T, Takai S. Case of fibrolipomatous hamartoma of the digital nerve without macrodactyly. J Nippon Med Sch 2011;78:388-92.  Back to cited text no. 3
    
4.
Hosian MM, Momen MM, Haque AK. Fibrolipomatous hamartoma of the digital branches of the median nerve. Pulse 2010;4:40-2.  Back to cited text no. 4
    
5.
Châtillon CE, Guiot MC, Jacques L. Lipomatous, vascular, and chondromatous benign tumors of the peripheral nerves : r0 epresentative cases and review of the literature. Neurosurg Focus 2007;22:E18.  Back to cited text no. 5
    
6.
Marom EM, Helms CA. Fibrolipomatous hamartoma : p0 athognomonic on MR imaging. Skeletal Radiol 1999;28:260-4.  Back to cited text no. 6
    
7.
Brodwater BK, Major NM, Goldner RD, Layfield LJ. Macrodystrophia lipomatosa with associated fibrolipomatous hamartoma of the median nerve. Pediatr Surg Int 2000;16:216-8.  Back to cited text no. 7
    
8.
Al-Jabri T, Garg S, Mani GV. Lipofibromatous hamartoma of the median nerve. J Orthop Surg Res 2010;5:71.  Back to cited text no. 8
    
9.
Guthikonda M, Rengachary SS, Balko MG, van Loveren H. Lipofibromatous hamartoma of the median nerve : c0 ase report with magnetic resonance imaging correlation. Neurosurgery 1994;35:127-32.  Back to cited text no. 9
    
10.
Bains R, Kotwal A, Saeed W. Recurrent carpal tunnel syndrome in a child due to fibrolipomatous hamartoma of the median nerve successfully treated by limited excision and decompression. J Plast Reconstr Aesthet Surg 2006;59:1394-7.  Back to cited text no. 10
    

Top
Correspondence Address:
Ranjan Agrawal
Department of Pathology, Rohilkhand Medical College Hospital, Pilibhit Bypass Road, Bareilly, Uttar Pradesh
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0377-4929.178241

Rights and Permissions


    Figures

  [Figure 1], [Figure 2], [Figure 3]



 

Top
 
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  


    Abstract
   Introduction
   Case report
   Discussion
   Conclusion
    References
    Article Figures

 Article Access Statistics
    Viewed1385    
    Printed38    
    Emailed0    
    PDF Downloaded61    
    Comments [Add]    

Recommend this journal