Journal of Orthopaedic Surgery 2004:12(2):248 252 Squamous cell carcinoma of the nail bed: Three case reports TC Wong, FK Ip, WC Wu Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Hong Kong ABSTRACT Squamous cell carcinoma of the nail bed is rare, and the disease is often misdiagnosed as a benign condition. Digital amputation is often performed because of the delay in diagnosis and the involvement of the distal phalanx. Between March 1999 and March 2002, 3 patients presented to the Pamela Youde Nethersole Eastern Hospital, Hong Kong, with squamous cell carcinoma of the nail bed. Two of the patients underwent a digit-salvaging procedure namely, wide local excision and flap coverage and their functional outcome was satisfactory. The remaining patient received partial amputation of the thumb without significant functional loss. A high degree of suspicion is thus needed to detect squamous cell carcinoma of the nail bed; a biopsy of chronic recurrent nail bed lesions should be performed. Key words: carcinoma, squamous cell; nail diseases; surgical flaps INTRODUCTION Squamous cell carcinoma (SCC) of the nail bed is a rare disease. Its diagnosis can be easily missed or delayed, because the clinical presentation is not specific and can mimic several benign inflammatory conditions, such as paronychia, pyogenic granuloma, or verruca vulgaris. Diagnosis can be made only by performing adequate biopsy. The treatment method Address correspondence and reprint requests to: Dr Tak-Chuen Wong, Medical Officer, Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Hong Kong. E-mail: tedwong2@i-cable.com
Vol. 12 No. 2, December 2004 Squamous cell carcinoma of the nail bed 249 depends on the extent of the tumour, and ranges from excision to digital amputation. In this article, we report 3 cases of SCC of the nail bed that were initially misdiagnosed as benign conditions. Two cases were successfully treated with wide local excision of the tumour and local flap coverage without digital amputation. CASE REPORTS Case 1 A 79-year-old male resident of an old-age home presented to a general practitioner in March 2002 because of pain and swelling over the radial side of the right ring finger that had lasted for more than 12 months. There was no history of trauma. The case was initially treated as one of paronychia, which was managed by incision, drainage, and antibiotic therapy. The patient presented to the Pamela Youde Nethersole Eastern Hospital in July 2002, because of swelling and erythema over the radial aspect of the right ring finger. There was no nail deformity, and no lymph node was palpable on the ipsilateral elbow and in the axillary regions. The clinical diagnosis was paronychia of the right ring finger. The lesion was excised, and the tissue was sent to a laboratory for culture and histological studies. The culture showed moderate growth of Staphylococcus aureus and heavy growth of coagulase-negative Staphylococcus species. Histological examination revealed moderately differentiated SCC with resection-margin involvement of the tumour cells (Fig. 1). Radiography did not reveal any bone involvement, and whole-body bone scanning using technetium Tc 99m demonstrated no distant metastasis. We performed wide local excision of the tumour, including half of the nail bed and the radial paronychium. The defect was covered with a homodigital advancement flap from lateral digital pulp tissue, and the donor site was covered by a full-thickness skin graft. The excision margins were clear. There was no local recurrence or distant metastasis at the 10-month follow-up visit. The flap and the donor site wound healed well and the finger regained its full function. The nail appeared smaller but was healthy (Figs. 2 and 3). Figure 1 Histology of the nail bed tissue in case 1. A photomicrograph shows islands of polygonal cells with pleomorphic hyperchromic nuclei, prominent nucleoli, abundant eosinophilic cytoplasm, intercellular bridges, and keratinised margins (H&E, x40). Figure 2 The flap and donor site wound healed well in case 1 after tumour excision. Case 2 A 40-year-old man presented to the Pamela Youde Nethersole Eastern Hospital in March 1999 with a 2-year history of a chronic discharging lesion in the radial aspect of the nail bed of the left thumb. Wedge Figure 3 Half of the nail remained in case 1 after wide local excision of the tumour and flap coverage.
250 TC Wong et al. Journal of Orthopaedic Surgery Wide local excision Tumour over radial side Radial advancement flap Figure 4 The lesion and design of flap coverage after excisional biopsy in case 2. Figure 6 The wound in case 2 healed after 9 months, but the nail appeared smaller. Figure 5 Excision of the lateral third of nail matrix and paronychium in case 2. The dorsal skin flap was elevated and rotated to cover the defect, and the donor site was covered with a full-thickness skin graft. excision and debridement of the nail bed had been performed 2 years earlier at the same hospital; the diagnosis at that time was pyogenic granuloma. We sent nail bed tissue for histological examination, which showed inflamed granulation tissue only; the patient recovered well but defaulted follow-up. He presented again in January 2001 for the same problem. Since the previous presentation, there had been persistent discharge and ulceration despite several episodes of debridement by other medical practitioners. Physical examination showed a small ulcer and granulomatous tissue at the radial aspect of the left thumb-nail; the ipsilateral axillary lymph node was not palpable. We performed excisional biopsy of the lesion. Culture showed the presence of Staphylococcus species, and the histological examination showed moderately differentiated SCC. Radiography did not show any bony lesion, and whole-body technetium bone scanning did not detect any distant metastasis. We performed wide local excision that included the lateral third of the nail matrix and the paronychium, and we used a dorsal radial advancement flap based on the radial neurovascular bundle to cover the defect (Fig. 4). The donor site wound was covered with a fullthickness skin graft that had been harvested from the ipsilateral wrist crease (Fig. 5). The resection margin was clear. At the 9-month follow-up, full function of the thumb had returned and there were no signs of tumour recurrence. The nail, however, was deformed (Fig. 6).
Vol. 12 No. 2, December 2004 Squamous cell carcinoma of the nail bed 251 Figure 7 An inflamed, necrotic, and discharging lesion lay over the radial side of the nail bed of the right thumb in case 3. Case 3 A 60-year-old man presented to the surgical department of the Pamela Youde Nethersole Eastern Hospital in March 2000 with a large granuloma underneath the nail of his right thumb. He had sustained a crush injury to the right thumb 6 months earlier, and this had resulted in swelling and mass formation. The case had been treated as one of pyogenic granuloma, and the mass had been excised under local anaesthesia. Histological examination of the mass had led to a diagnosis of SCC. At presentation, physical examination showed an irregular ulcerative lesion over the radial side of the nail bed of the right thumb. There were also erythematous changes and discharge from the lesion (Fig. 7). Radiography of the chest and whole-body technetium bone scanning did not show any evidence of distant metastasis. We performed an amputation at the neck at the proximal phalanx level of the right thumb. Histological examination of the resected specimen showed that the resection margin was clear. The wound healed satisfactorily and there was minimal functional disability (Fig. 8). Figure 8 The wound in case 3 healed well. DISCUSSION Although SCC of the nail bed is rare, it is the most common primary malignant neoplasm of the nail bed. Affected individuals are usually aged 50 to 59 years. 1 The diagnosis is often delayed or missed, simply because of the rarity of the disease and lack of awareness about the disease among surgeons. Early signs of malignancy are often obscured by the nail plate another reason for the delayed diagnosis. 2 Most reported cases involve only a single digit most commonly the thumb. The aetiology of the tumour remains uncertain; trauma, chronic infections, radiation exposure, human papillomavirus infection, and chronic radiodermatitis have been suggested. 3 5 In terms of tumour progression, SCC of the nail bed seems to be less aggressive than SCC arising in other parts of the body. Axillary lymph node involvement and distant metastasis are uncommon. 6 John 7 reported 3 cases of soft enlargement of the ipsilateral axillary node that resolved after digit amputation; these cases were most likely due to an inflammatory reaction secondary to the chronic infection of the nail bed. Reports show that bone is involved in 17% 8 to 66% 6 of cases, which may be a result of delayed diagnosis. The choice of treatment depends on the extent of the tumour. For pre-invasive lesions without bone
252 TC Wong et al. Journal of Orthopaedic Surgery involvement, Mohs technique has achieved successful outcomes. 9 11 The technique essentially a microscopically controlled excision guides the margin of excision and helps minimise tissue loss to save the digit. Wide local excision and coverage by a local flap is also a successful method, as illustrated in our case series: the quality of the flaps was satisfactory, the functional and cosmetic outcomes of the digits were good, and there was minimal donor-site morbidity. For invasive tumours with bone involvement, digital amputation is the treatment of choice. Amputation of the middle phalanx should also be considered if bone involvement is extensive. 1,6 To conclude, SCC involving the nail bed is not common. A high degree of suspicion is thus needed to detect this condition. For patients who present with a chronic or recurring nail lesion after initial treatment, a biopsy is recommended. This approach would be the only way to make a proper diagnosis. Wide local excision and flap coverage are recommended for pre-invasive tumours (i.e. when bony tissue is not involved) to achieve satisfactory functional results. REFERENCES 1. Yip KM, Lam SL, Shee BW, Shun CT, Yang RS. Subungual squamous cell carcinoma: report of 2 cases. J Formos Med Assoc 2000;99:646 9. 2. Onukak EE. Squamous cell carcinoma of the nailbed: a diagnostic and therapeutic problem. Br J Surg 1980;67:893 4. 3. Ashinoff R, Li JJ, Jacobson M, Friedman-Kien AE, Geronemus RG. Detection of human papillomavirus DNA in squamous cell carcinoma of the nail bed and finger determined by polymerase chain reaction. Arch Dermatol 1991;127:1813 8. 4. Zabawski EJ Jr, Washak RV, Cohen JB, Cockerell CJ, Brown SM. Squamous cell carcinoma of the nail bed: is finger predominance another clue to etiology? A report of 5 cases. Cutis 2001;67:59 64. 5. Guitart J, Bergfeld WF, Tuthill RJ, Tubbs RR, Zienowicz R, Fleegler EJ. Squamous cell carcinoma of the nail bed: a clinicopathological study of 12 cases. Br J Dermatol 1990;123:215 22. 6. Carroll RE. Squamous cell carcinoma of the nail bed. J Hand Surg Am 1976;1:92 7. 7. John HT. Primary skin cancer of the fingers simulating chronic infection. Lancet 1956;270:662 4. 8. Attiyeh FF, Shah J, Booher RJ, Knapper WH. Subungual squamous cell carcinoma. JAMA 1979;241:262 3. 9. Mikhail GR. Bowen disease and squamous cell carcinoma of the nail bed. Arch Dermatol 1974;110:267 70. 10. Mikhail GR. Subungual epidermoid carcinoma. J Am Acad Dermatol 1984;11:291 8. 11. Goldminz D, Bennett RG. Mohs micrographic surgery of the nail unit. J Dermatol Surg Oncol 1992;18:721 6.