Glomus tumor-induced longitudinal splitting of nail mimicking median canaliform dystrophy
S B Verma
18, Amee Society, Diwalipura, Vadodara - 390 015
|How to cite this article:
Verma S B. Glomus tumor-induced longitudinal splitting of nail mimicking median canaliform dystrophy. Indian J Dermatol Venereol Leprol 2008;74:257-259
AbstractMedian canaliform deformity of the nail is an uncommon entity, where there is longitudinal splitting of the nail. Longitudinal splitting of the nail is a rare phenomenon and can also occur following number of growths arising in the nail matrix. On examination there was a longitudinal split in the nail plate, beginning in the distal nail fold and extending proximally all the way to the proximal nail fold. There was a small, almost indiscernible, swelling in that area, which was exquisitely tender. The split part of the nail showed a little discoloration. There was no discharge, bleeding, or subungual mass visible. 'Love test' was positive in this case. After nail avulsion, a small 2 mm x 4 mm nodule was exposed and excised. Histopathological examination of the tumor showed a mantle of glomus cells surrounding the blood vessels.
Longitudinal splitting of the nail as seen in median canaliform dystrophy is most commonly reported following chronic trauma. However, underlying tumors of the matrix can also cause longitudinal splitting. An interesting case of glomus tumor of the nail causing a longitudinal splitting of the nail, resembling median canaliform dystrophy, is being reported.
A 72-year-old Spanish missionary reported to this clinic with an exquisitely painful left thumb nail, which was also split in the center. He said that he had developed this split a couple of years ago; when he also noticed pain, which gradually became more intense. The longitudinal split in the nail also grew during that period. He complained of severe pain even when his finger touched a hard surface. There was no history of drug intake or any family history of a similar affliction. There was no history of any repeated trauma or any habit tic involving manipulation of the nail apparatus.
On examination there was a longitudinal split in the nail plate, beginning in the distal nail fold and extending proximally all the way to the proximal nail fold [Figure - 1]. There was a small, almost indiscernible, swelling in that area, which was exquisitely tender. The split part of the nail showed a little discoloration. There was no discharge, bleeding, or a subungual mass visible. ′Love test′ was positive in this case, i.e., pressure applied over the lesion with the tip of a pencil eliciting excruciating pain. A provisional diagnosis of longitudinal nail splitting mimicking median canaliform dystrophy of the nail due to an underlying glomus tumor was made. The nail plate was avulsed, and the nail bed and matrix were explored. A small bluish nodule measuring about 2 mm x 4 mm was seen in the matrix. The tumor was excised and the site was sutured.
Histopathological examination of the tumor showed a mantle of glomus cells surrounding the blood vessels [Figure - 2]. The cells were rounded and uniform, with eosinophilic cytoplasm and round-to-oval nuclei. The stroma at places was conspicuously myxoid. There were no features of cellular or nuclear pleomorphism. A diagnosis of glomus tumor was made. The longitudinal split in the center of the nail, mimicking median canaliform dystrophy of the nail, was logically assumed to be secondary to the glomus tumor.
Median canaliform dystrophy of Heller (dystrophia unguis mediana canaliformis, solenonychina, nevus striatus unguis), as the name suggests, is a dystrophic condition of the nail in which longitudinal splitting occurs.  It is almost exclusively seen on the thumbs, and often there is bilateral involvement of thumbnails. In most cases, there is a fir-tree pattern, which was not seen in this case. 
Repeated trauma, especially manipulating the central part of the cuticle, has been implicated in this disorder. However, it is not seen uniformly in all cases of median canaliform deformity of the nail. ,,3] There can be waxing and waning or persistence of the lesion despite many years of scrupulous avoidance of any trauma. That questions the widely supported belief that the entity is secondary to chronic trauma.  Isolated cases of its association with isotretinoin therapy and a familial occurrence have been reported. , Benign and malignant tumors like glomus tumor, myxoid cyst, papilloma, squamous cell carcinoma, malignant melanoma, etc., can have a subungual location and can cause nail dystrophy, including longitudinal grooving and lifting of the nail plate from the bed. ,
It is suggested that glomus tumors should always be kept in mind when considering differential diagnosis of any painful condition of the terminal digit.  Subungual solitary glomus tumors (neuromyoarterial tumors) can either be skin colored or bluish. They are usually extremely tender, and there can be constant severe pain which radiates upon touch or change in temperature. ,, They can also cause concave surface erosions of the underlying bone, seen by a plain x-ray. Histopathologically, they are characterized by cuff of uniform glomus cells surrounding vascular lumina.  The vascular lumina may either be inconspicuous or be very prominent to merit the appellation of glomangioma. There may be a transition from glomus cells to smooth muscle cells too, which is when it is known as glomangiomyoma. In addition to these features, some glomus cell tumors show abundant myxoid stroma, which was true for this case too.  A complete excision is indicated for relief of pain; however, when present in subungual location, their small size makes them difficult at times to be located and eradicated. , In our case too, one small tumor measuring 2 mm x 4 mm was not visible until the nail was avulsed.
A glomus tumor induced longitudnal splitting of the nail resembling a medial canaliform deformity of the nail without the fir tree pattern is being reported.
I thank Dr. Mayur Jani, plastic surgeon, for the surgical intervention.
Odom R, James W, Berger T. In : Diseases of the skin appendages. Andrew's Diseases of the Skin. 9 th ed. Philadelphia: WB Saunders and Co; 2000. p. 984-5.th ed. Philadelphia: WB Saunders and Co; 2000. p. 984-5.'>[Google Scholar]
Disorders of nails. Berker de DA, Baran R, Dawber RP, editors. In : Rook's Textbook of Dermatology. Vol 4 Blackwell Science. Oxford: Median Canaliform Dystrophy; 2004. p. 54-5.[Google Scholar]
Baran R, de Berker de DA, Dawber R. In nails: Appearance and therapy. 1 st ed. London: Martin Dunitz; 1993. p. 16-7.[Google Scholar]
Bottomley WW, Cunliffe WJ. Median nail dystrophy associated with isotretinoin therapy. Br J Dermatol 1992;127:447-8.[Google Scholar]
Griego RD, Orengo IF, Scher RK. Median nail dystrophy and habit tic deformity: Are they different forms of the same disorder? Int J Dermatol 1995;34:779-800.[Google Scholar]
Sweeney SA, Cohen PR, Schulze KE, Nelson BR. Familial median canaliform nail dystrophy. Cutis 2005;75:161-5.[Google Scholar]
Ozdemir O, Coskunol E, Ozalp T, Ozaksar K. Glomus tumors of the finger: A report on 60 cases. Acta Orthop Traumatol Turc 2003;37:244-8.[Google Scholar]
Calonje E, Mackie RM. Soft tissue tumours and tumour-like conditions. In : Rook's Textbook of Dermatology. Vol 3. Oxford: Blackwell Science; 2004. p. 31-2.[Google Scholar]
Moon SE, Won JH, Kwon OS, Kim JA. Subungual glomus tumor: Clinical manifestations and outcome of surgical treatment. J Dermatol 2004;31:993-7.[Google Scholar]
Weedon D. Vascular Tumors. Skin Pathology. 4 th ed. Edinburgh: Churchill Livingstone; 1997. p. 835-6.[Google Scholar]
Takata H, Ikuta Y, Ishida O, Kimori K. Treatment of subungual glomus tumour. Hand Surg 2001;6:25-7.[Google Scholar]