The authors report a novel case of solitary infantile myofibroma originating from the conjunctiva and encroaching over the limbus. This is an observational case report with clinicopathologic correlation. Immunostaining of the lesion was positive for vimentin and smooth muscle actin, and negative for pancytokeratin, desmin, myogenin, EMA, myoglobin, HMB45, and MelanA. To the authors’ knowledge, this is the first reported case of myofibroma originating from the conjunctiva and this case highlights the importance of considering myofibromatosis in the differential diagnosis of unusual conjunctival lesions.
From the Princess Alexandra Eye Pavilion (GL, MG, MM), Edinburgh; and St. Georges Hospital (LB), London, United Kingdom.
Presented at the British Isles Paediatric Ophthalmology & Strabismus Association Annual Meeting, September 24, 2009, Glasgow, United Kingdom.
The authors have no financial or proprietary interest in the materials presented herein.
Address correspondence to Gerassimos Lascaratos, MSc(Oxon), MRCSEd, Princess Alexandra Eye Pavilion, Chalmers Street, Edinburgh, EH3 9HA, United Kingdom.
Received: October 15, 2009
Accepted: February 24, 2010
Posted Online: May 21, 2010
The group of fibromatoses consists of non-metastasizing fibrous tumors that invade locally and may recur after surgical excision. Juvenile fibromatosis was initially described by Stout in 1954.1 Following recognition of the myofibroblastic nature of the constituent cells, Chung and Enzinger reported 61 cases of this entity in 1981 and renamed it infantile myofibromatosis.2 It is a mesenchymal disorder of early infancy characterized by the formation of tumors in skin, subcutaneous tissues, muscle, bone, and viscera. Most tumors are recognized at birth or before age 2 years. It occurs in the head and neck region in 36%, trunk in 33%, lower extremity in 18%, and upper extremity in 13% of cases.2 Ocular involvement is rare and is generally limited to the eyelids and orbit.3–5 A single case of solitary myofibroma involving the sclera has also been recorded6 and another case of fibromatosis of the cornea in association with congenital generalized fibromatosis was described in 1974.7 To the best of our knowledge, this is the first case of myofibroma originating from the conjunctiva to be reported in the literature.
A 19-month-old girl of mixed white and Chinese origin presented with an 8-month history of left medial conjunctival vascular lesion in November 2007. She was otherwise fit and well, and physical examination, including cutaneous examination, was within normal limits. Cycloplegic refraction showed mild and equal hypermetropia bilaterally. Dilated funduscopy was unremarkable. A red patch was seen at the nasal aspect of the left conjunctiva and the appearance was initially thought to be consistent with a resolving subconjunctival hemorrhage or a capillary hemangioma. The lesion remained unchanged for approximately 9 months, then was seen to increase in size and invade the cornea (Fig. 1). Initial surgical excision of the lesion was incomplete and increased opacification of the cornea was seen at a follow-up visit 6 weeks after surgery. She therefore underwent a further excision of the residual lesion with conjunctival autograft from the superior fornix of the same eye.
Figure 1. Conjunctival Myofibroma Invading the Cornea.
Histopathologic analysis of the lesion showed conjunctival mucosa covered by stratified squamous epithelium in places with spindle-cell proliferation within the substantia propria (Fig. 2). The cells were arranged in fascicles and there was moderate nuclear polymorphism and occasional binucleate forms. Occasional mitoses were found. Focal lymphocytic infiltration was noted and the stroma was fibrotic in places. A reticulin stain showed a pericellular reticulin pattern. The proliferation extended into the wall of some vessels. Immunostaining was positive for vimentin and smooth muscle actin (Fig. 3) and negative for S100 protein and desmin, consistent with myofibroblastic differentiation. Immunostaining was also negative for pancytokeratin, myogenin, CD34, CD31, MNF118, AE1/AE3, EMA, myoglobin, HMB45, and MelanA. Immunostaining for Ki67 showed a moderate proliferation rate. The histological picture may vary from one field to another within an individual tumor, making needle biopsy, frozen section, or incisional biopsy inadequate and even misleading8 and emphasizing the importance of excisional biopsy in the management of these lesions. Our studies support this characteristic variation in pattern, with areas composed of densely cellular spindle-shaped cells coexisting with vascularized areas and fibrotic and chronic inflammatory lymphocytic foci.
Figure 2. Conjunctival Mucosa with Stratified Squamous Epithelium (Upper Left Quadrant, Running from Lower Left to Upper Right) and Underlying Proliferation of Plump Spindle-Shaped Cells (Hematoxylin–Eosin, Original Magnification ×20). Scale Bar = 100 Microns.
Figure 3. The Spindle-Shaped Cells Form Interlacing Fascicles and Stain Positively for Smooth Muscle Actin (Hematoxylin–Eosin, Original Magnification ×20). Scale Bar = 100 Microns.
Solitary and multiple myofibromas confined to soft tissues and bone carry a good prognosis; they rarely require more than an excisional biopsy and many tend to regress spontaneously.9 In the review by Wiswell et al., only 5 of 54 (9%) solitary lesions recurred locally following excision (with many of the excisions incomplete).10 In addition, there was spontaneous regression in 11 of 18 patients with multicentric lesions without visceral involvement and a follow-up of more than 1 year,10 possibly through an apoptotic mechanism.11 Chung and Enzinger also found that only 3 of 28 solitary lesions (11%) locally recurred and 5 of the 15 multicentric lesions showed spontaneous regression.2 On the other hand, as many as 73% of neonates or infants with multiple visceral lesions have died, with signs of respiratory distress or diarrhea soon after birth.10 In the current case, clinical examination did not raise any concerns with regard to the presence of other myofibromatous lesions and, in the absence of any relevant symptomatology, no further radiologic investigation was sought. Cutaneous examination was essential to confirm the absence of cutaneous sebaceous nevi and differentiate this entity from the organoid nevus syndrome with its associated epibulbar complex choristomas. This case was unusual for the occurrence of a solitary myofibroma originating from the conjunctiva and highlights the importance of considering myofibromatosis in the differential diagnosis of unusual conjunctival lesions.
- Stout AP. Juvenile fibromatoses. Cancer. 1954;7:953–978. doi:10.1002/1097-0142(195409)7:5<953::AID-CNCR2820070520>3.0.CO;2-W [CrossRef]
- Chung EB, Enzinger FM. Infantile myofibromatosis. Cancer. 1981;48:1807–1818. doi:10.1002/1097-0142(19811015)48:8<1807::AID-CNCR2820480818>3.0.CO;2-G [CrossRef]
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- Choopong P, Nielsen PG, Perlman EM, Huang JJ, Dryja TP, Foster CS. Solitary myofibroma of the sclera. Cornea. 2007;26:114–116. doi:10.1097/01.ico.0000243951.07096.fd [CrossRef]
- Antine BE, Brown FM, Arisco MJ. Fibroma of the cornea: report of a case associated with congenital generalized fibromatosis. Arch Ophthalmol. 1974;91:278–280.
- Richardson WR, Dewar JP. Problems in managing fibrous tissue tumors in infants and children. Surgery. 1964;56:426–436.
- Goldblum JR, ed. Enzinger and Weiss’s Soft Tissue Tumours, 4th ed. St. Louis: Mosby; 2001:347–408.
- Wiswell TE, Davis J, Cunningham BE, Solenberger R, Thomas PJ. Infantile myofibromatosis: the most common fibrous tumor of infancy. J Pediatr Surg. 1988;23:315–318. doi:10.1016/S0022-3468(88)80196-9 [CrossRef]
- Fukasawa Y, Ishikura H, Takada A, et al. Massive apoptosis in infantile myofibromatosis: a putative mechanism of tumor regression. Am J Pathol. 1994;144:480–485.