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Cylindrical deformity of the nail plate secondary to subungual myxoma
Cylindrical deformity of the nail plate secondary to subungual myxoma Frederick W. Gourdin, M D and Pearon G. Lang, Jr., MD Augusta, Georgia, and
Charleston, South Carolina Digital myxomas are rare neoplasms. We describe a subungual myxoma arising in a previously unreported location, the nail matrix. This produced an interesting cylindrical deformity of the nail. Complete surgical excision is usually curative. (J Am Acad Dermatol 1996;35: 846-8.) Myxomas are benign minors composed of stellate cells in a loose mucoid stroma. Most myxomas arise in the heart, muscles, or jaw and rarely arise in a digit. W e describe a m y x o m a arising from the nail matrix, producing an unusual deformity of the nail. CASE REPORT A 39-yearold black man had an elongated, thick, cylindrical deformity of the right index finger nail plate of approximately 6 years' duration. He had experienced significant trauma to this digit some 20 years previously. The lesion was painful when he tried to perform his duties as a computer operator. Examination revealed a 2.4 x 1.3 cm nail plate with a peculiar "tubelike" appearance. The proximal nail fold was elevated by the deformed nail plate, which tapered somewhat toward its distal end. There appeared to be a space within the cylindrically deformed distal nail plate (Fig. 1). Radiographs of the distal phalanx were normal. Under 1% plain lidocaine digital block, the nail was removed revealing a soft, gelatinous 1.8 x 1.4 x 0.8 cm mass projecting from beneath the proximal nail fold (Fig. 2), lying atop the nail bed, and filling the space within the cylindrical nail plate (Fig. 3). The proximal nail fold was reflected and the well-defined mass was resected. Light microscopy revealed a rumor surrotmded in part by a pseudocapsule (Fig. 3). The tumor was relatively avascular and was composed of stellate cells embedded in a loose mucoid stroma (Fig. 4). Chondroblasts, rhabOmHO
This article is made possible through an educational grant from the Dermatological Division, Ortho Pharmaceutical Corporation.
From the Medical College of Georgia, Augusta, and the Medical University of South Carolina, Charleston. Reprint requests: Frederick W. Gourdin, MD, Section of Dermatology, Medical College of Georgia, 1004 Chafee Avenue, Augusta, GA 30912-3190. Copyright © 1996 by the American Academy of Dermatology, Inc. 0190-9622/96 $5.00 + 0
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Fig. 1. Distal aspect of nail plate after removal. Note cavity within nail plate.
domyoblasts, lipoblasts, and neuroid elements were absent. S- 100 stain was negative. Alcian-blue stain at pH 0.5 and 2.5 was positive. DISCUSSION Virchow 1 first used the term myxoma to characterize tumors that resemble myxomatous tissues of the umbilical cord. Stout 2 proposed four criteria for diagnosis: (1) the minor is composed of spindleshaped cells set in a loose matrix of reticulin and collagen fibers; (2) the tumor is poorly vascularized; (3) there must be no recognizable differentiated cellular elements such as chondroblasts, lipoblasts, or rhabdomyoblasts; and (4) the tumor is of unicentric origin, grows by infiltration or by expansion, and does not metastasize. The cause of these lesions i:
Journal of the AmericanAcademyof Dermatology Volume 35, Number 5, Part 2
Gourdin and Lang 847
Fig. 2. Tumor lying atop nail bed.
Fig. 3. Ventral view ofresected rumor and surrounding nail plate after excision.
unclear. Some authors believe that they are derived from primitive mesenchymal cells with the capability for multipotential differentiation. Others have suggested that they arise from fibroblasts that produce excessive mucopolysaccharides, which may interfere with the polymerization of normal collagen. 3 Most myxomas occur in the heart, muscles of the extremities, and the jaw. However, these tumors occur rarely in other locations including the fingers and toes.4-s They may also arise from bone or soft tissues; including the dermis. They have been reported as arising from the skin of the distal phalanx, from the pulp tissues of the distal phalanx, from the nail bed, and from the periosteum and bone of the distal phalanx deep to the nail bed. We believe that our patient's tumor arose from the matrix, because it was totally ensheathed by nail plate except at the level of the proximal matrix. Tumors arising from extraosseous locations do not usually produce roent-
genographic changes. Myxomas arising in bone develop in the marrow and characteristically show an expansile lesion of the bone surrounded by a thin shell of intact bone. Those derived from periosteum show nonexpansile osteolytic destruction of the bone surrounded by sclerotic edges, s The differential diagnosis of myxoid lesions includes tumors with marked myxoid degeneration such as chondrosarcoma, fibrosarcoma, chondroma, and chondromyxoid fibroma. These usually can be excluded histologically by the absence of differentiated elements. In addition, the myxoid cyst and ganglion must be considered but can be excluded by their cystic nature. 7' s The treatment for myxoma is surgical excision. This surgery is usually best performed with the patient under digital nerve block. The nail plate is removed to explore the subungual mass. When the tumor appears to arise deep to the proximal nail fold, as in our patient, the nail fold should be incised bi-
848
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Journal of the American Academy of Dermatology November 1996
F i g . 4. Hematoxylin-eosin stain of rumor; original magnification x l 0 .
laterally and reflected to fully expose the tumor (Fig. 3). Generally, the recurrence rate is thought to be low if the rumor is fully excised. The proximal nail fold is attached with one or two sutures on each side at the conclusion of the procedure. Subungual tumors arising from the bony phalanx may require curettage of the bone and, rarely, partial digital amputation], 8 REFERENCES
1. Virchow R, cited by Dutz W, Stout AP. The my×oma in childhood. Cancer 1961;14:629-35.
2. Stout AP. Myxoma: the rumor of primitive mesenchyme. Ann Surg 1948;127:706-19. 3. Enzinger FE, Weiss SW. Soft Tissue Tumors. St. Louis: CV Mosby, 1988;918. 4. Hill TL, Jones BE, Park KH. Myxoma of the skin of a fingeT. J Am Acad Dermatol 1990;22:343-45. 5. Winke BM, Blair WF, Benda JA. Myxomas in the fingertips. Clin Orthop 1988;237:271-5. 6. Sanusi ID. Subungual myxoma. Arch Dermatol 1982; 118:612-4. 7. Hill JA, Victor TA, Dawson WJ. Myxoma of the toe. J Bone Joint Surg 1978;128:128-9. 8. Kaehr D, Klug MS. Subungual myxoma. J Hand Surg 1986;11:73-6.
Charleston, South Carolina Digital myxomas are rare neoplasms. We describe a subungual myxoma arising in a previously unreported location, the nail matrix. This produced an interesting cylindrical deformity of the nail. Complete surgical excision is usually curative. (J Am Acad Dermatol 1996;35: 846-8.) Myxomas are benign minors composed of stellate cells in a loose mucoid stroma. Most myxomas arise in the heart, muscles, or jaw and rarely arise in a digit. W e describe a m y x o m a arising from the nail matrix, producing an unusual deformity of the nail. CASE REPORT A 39-yearold black man had an elongated, thick, cylindrical deformity of the right index finger nail plate of approximately 6 years' duration. He had experienced significant trauma to this digit some 20 years previously. The lesion was painful when he tried to perform his duties as a computer operator. Examination revealed a 2.4 x 1.3 cm nail plate with a peculiar "tubelike" appearance. The proximal nail fold was elevated by the deformed nail plate, which tapered somewhat toward its distal end. There appeared to be a space within the cylindrically deformed distal nail plate (Fig. 1). Radiographs of the distal phalanx were normal. Under 1% plain lidocaine digital block, the nail was removed revealing a soft, gelatinous 1.8 x 1.4 x 0.8 cm mass projecting from beneath the proximal nail fold (Fig. 2), lying atop the nail bed, and filling the space within the cylindrical nail plate (Fig. 3). The proximal nail fold was reflected and the well-defined mass was resected. Light microscopy revealed a rumor surrotmded in part by a pseudocapsule (Fig. 3). The tumor was relatively avascular and was composed of stellate cells embedded in a loose mucoid stroma (Fig. 4). Chondroblasts, rhabOmHO
This article is made possible through an educational grant from the Dermatological Division, Ortho Pharmaceutical Corporation.
From the Medical College of Georgia, Augusta, and the Medical University of South Carolina, Charleston. Reprint requests: Frederick W. Gourdin, MD, Section of Dermatology, Medical College of Georgia, 1004 Chafee Avenue, Augusta, GA 30912-3190. Copyright © 1996 by the American Academy of Dermatology, Inc. 0190-9622/96 $5.00 + 0
846
16/4/72962
Fig. 1. Distal aspect of nail plate after removal. Note cavity within nail plate.
domyoblasts, lipoblasts, and neuroid elements were absent. S- 100 stain was negative. Alcian-blue stain at pH 0.5 and 2.5 was positive. DISCUSSION Virchow 1 first used the term myxoma to characterize tumors that resemble myxomatous tissues of the umbilical cord. Stout 2 proposed four criteria for diagnosis: (1) the minor is composed of spindleshaped cells set in a loose matrix of reticulin and collagen fibers; (2) the tumor is poorly vascularized; (3) there must be no recognizable differentiated cellular elements such as chondroblasts, lipoblasts, or rhabdomyoblasts; and (4) the tumor is of unicentric origin, grows by infiltration or by expansion, and does not metastasize. The cause of these lesions i:
Journal of the AmericanAcademyof Dermatology Volume 35, Number 5, Part 2
Gourdin and Lang 847
Fig. 2. Tumor lying atop nail bed.
Fig. 3. Ventral view ofresected rumor and surrounding nail plate after excision.
unclear. Some authors believe that they are derived from primitive mesenchymal cells with the capability for multipotential differentiation. Others have suggested that they arise from fibroblasts that produce excessive mucopolysaccharides, which may interfere with the polymerization of normal collagen. 3 Most myxomas occur in the heart, muscles of the extremities, and the jaw. However, these tumors occur rarely in other locations including the fingers and toes.4-s They may also arise from bone or soft tissues; including the dermis. They have been reported as arising from the skin of the distal phalanx, from the pulp tissues of the distal phalanx, from the nail bed, and from the periosteum and bone of the distal phalanx deep to the nail bed. We believe that our patient's tumor arose from the matrix, because it was totally ensheathed by nail plate except at the level of the proximal matrix. Tumors arising from extraosseous locations do not usually produce roent-
genographic changes. Myxomas arising in bone develop in the marrow and characteristically show an expansile lesion of the bone surrounded by a thin shell of intact bone. Those derived from periosteum show nonexpansile osteolytic destruction of the bone surrounded by sclerotic edges, s The differential diagnosis of myxoid lesions includes tumors with marked myxoid degeneration such as chondrosarcoma, fibrosarcoma, chondroma, and chondromyxoid fibroma. These usually can be excluded histologically by the absence of differentiated elements. In addition, the myxoid cyst and ganglion must be considered but can be excluded by their cystic nature. 7' s The treatment for myxoma is surgical excision. This surgery is usually best performed with the patient under digital nerve block. The nail plate is removed to explore the subungual mass. When the tumor appears to arise deep to the proximal nail fold, as in our patient, the nail fold should be incised bi-
848
Gourdin and Lang
Journal of the American Academy of Dermatology November 1996
F i g . 4. Hematoxylin-eosin stain of rumor; original magnification x l 0 .
laterally and reflected to fully expose the tumor (Fig. 3). Generally, the recurrence rate is thought to be low if the rumor is fully excised. The proximal nail fold is attached with one or two sutures on each side at the conclusion of the procedure. Subungual tumors arising from the bony phalanx may require curettage of the bone and, rarely, partial digital amputation], 8 REFERENCES
1. Virchow R, cited by Dutz W, Stout AP. The my×oma in childhood. Cancer 1961;14:629-35.
2. Stout AP. Myxoma: the rumor of primitive mesenchyme. Ann Surg 1948;127:706-19. 3. Enzinger FE, Weiss SW. Soft Tissue Tumors. St. Louis: CV Mosby, 1988;918. 4. Hill TL, Jones BE, Park KH. Myxoma of the skin of a fingeT. J Am Acad Dermatol 1990;22:343-45. 5. Winke BM, Blair WF, Benda JA. Myxomas in the fingertips. Clin Orthop 1988;237:271-5. 6. Sanusi ID. Subungual myxoma. Arch Dermatol 1982; 118:612-4. 7. Hill JA, Victor TA, Dawson WJ. Myxoma of the toe. J Bone Joint Surg 1978;128:128-9. 8. Kaehr D, Klug MS. Subungual myxoma. J Hand Surg 1986;11:73-6.