Subungual exostosis: case report and review of the literature

Subungual Exostosis Presenting as a Pyogenic Granuloma-like Lesion with Reactive Myofibroblastic Proliferation in Two Young Women

Subungual exostosis (SE) is a well-recognised benign proliferation of the distal phalanx most often seen in young adults and affecting the big toe. Possible triggers include previous trauma and chronic irritation or infection. We describe two atypical cases of SE in two young women presenting with pyogenic granuloma-like lesions clinically. Diagnostic biopsies were performed to confirm the diagnosis and excluded amelanotic melanoma. However, histology unexpectedly revealed reactive myofibroblastic proliferations mimicking nodular fasciitis overlying the SE. Given the atypical clinical presentation, the diagnosis was initially missed or not considered in both patients. They highlight two important points; the first is that SEs may present with pyogenic granuloma-like lesions clinically and that histological analysis is then required to exclude malignancy, particularly amelanotic melanoma. Secondly, that the histology will show a reactive myofibroblastic proliferation and if the sample is relatively superficial and pathologists are not aware of this potential reaction pattern, the underlying diagnosis of SE may be missed.

Subungual Exostosis on the Right Hallux

Subungual exostosis (SE) is a benign, relatively uncommon bony growth underneath the nails of the distal phalanx of toes or fingers, with a majority on the toes. Clinically, it has two subvariants-protruded and nonprotruded growths from nail plates-which are treated differently. In this article, we report a case of protruded SE in a teenager with illustrative surgical excision. A 15-year-old boy presented with a painful growth on his right great toe of 6 months' duration. Physical examination revealed a 1-cm-diameter, solid, erythematous, rough, irregular growth penetrating through the skin along the dorsolateral nail bed of the right hallux with deformity of the lateral nail plate. Radiographs showed an elevated mass over the distal phalanx of the right lateral hallux. The mass was surgically excised and histopathologic examination confirmed the diagnosis of SE. The patient had no relapse or recurrence at follow-ups of 6 and 18 months. Subungual exostosis is a relatively uncommon bony growth in the toes. Radiography is favored for the diagnosis. Complete surgical excision is the optimal treatment, with rare recurrence. It needs to be differentiated from other bony lesions, including bizarre parosteal osteochondromatous proliferation, myositis ossificans, fibro-osseous pseudotumor, osteochondroma, and enchondroma.

Fibro-Osseous Pseudotumor

Fibro-osseous pseudotumor is an extremely rare subcutaneous benign ossifying lesion associated with bone formation that is most commonly seen in the hands, followed by the toes. Because the tumor has a certain degree of invasiveness, it is often mistaken for malignancy, which leads to radical, excessive treatment. Our case involved a 32-year-old man with lesions on the left index finger. We documented the detailed data of diagnosis, treatment, and follow-up. We also conducted a review and summarized the published cases to advance our understanding of the disease, provide more accurate diagnostic criteria, and avoid inappropriate surgical procedures. [Orthopedics. 2021;44(6):e713-e718.].

Some Reactive Lesions of Bone Are Probably Neoplasms: A Review

CONTEXT.—

A number of fibro-osseous and osteocartilaginous lesions, especially common in the small bones of hand and feet, pose a diagnostic challenge and have historically been thought to be reactive lesions. However, modern molecular techniques when supplementing clinical, radiographic, and histologic evaluation suggest they may, in fact, be neoplasms.

OBJECTIVE.—

To review the clinical presentation and histopathologic, molecular, and radiologic features of selective bone lesions, focusing most specifically on subungual exostosis, florid reactive periostitis, and bizarre periosteal osteochondromatous proliferation.

DATA SOURCES.—

Literature review and personal experience are the source of this review.

CONCLUSIONS.—

Some lesions previously thought to be reactive are locally aggressive and demonstrate reproducible molecular abnormalities, and thus may be neoplasms. Although most common in the bones of the fingers and toes, these lesions also occur in long and other bones. The clinical presentations, radiologic appearances, and histopathologic features often overlap, making the diagnosis challenging, and these lesions may require molecular evaluation to maximize accurate prognostication.

A Novel Use of Umbilical Perinatal Graft in Subungual Exostosis Resection

Nail pathologies have a broad range of origin and may sometimes be complicated in presentation or clinical course, specifically when the pathology remains recalcitrant after treatment. In this case report we discuss a pathologic disorder that was initially misdiagnosed as a pyogenic granuloma surrounding an ingrown nail but was later found to be a benign neoplastic bone growth, Dupuytren exostosis, also known as a subungual exostosis. Operative treatment was deemed appropriate for the patient, and the exostosis was resected, leaving a soft-tissue void at the distal toe. The remaining void was filled with a perinatal graft, the use of which has been deemed effective anecdotally in both chronic and acute lower-extremity wounds but has not been widely discussed in the lower-extremity literature. This graft was placed to aid in wound healing over a potentially difficult wound bed. As amniotic, chorionic, and umbilical grafts become more prevalent in lower-extremity surgery, its antitumor effects should be further explored and published. This is the first case report, to our knowledge, of the successful use of a perinatal graft in the setting of a bone tumor, and it demonstrates that certain benign neoplasms can be treated with resection and placement of a perinatal graft while helping to prevent chronic wounds at surgical sites.

Subungual exostosis - treatment results with preservation of the nail bed

Subungual exostosis is a rare benign osteocartilaginous tumor, of unknown etiology, that affects the subungual part of the distal phalanx and predominantly affects adolescent females. The objective of this study is to evaluate the results of surgical treatment of subungual exostosis in pediatric patients by means of surgical excision and nail preservation. We present a retrospective study, including pediatric patients with subungual exostosis who underwent surgical treatment in a single institution, over a 6-year period, We describe the surgical technique used, the characteristics of the patients and lesions, and evaluate the results obtained in terms of function, satisfaction and complications. Thirteen patients were included in this study, seven female (54%) and six male (46%), median age 11 years old. The most common location was the hallux, in eight patients (73%). Patients had good functional results with a median American Orthopedic Foot & Ankle Society score of 100 [80; 100] and a median personal satisfaction score of 9. The median follow-up was 30 [3;68] months. In our patients, subungual excision with nail bed preservation, allows a good balance between the radical excision of the exostosis and the preservation of the natural protection granted by the native nail, yielding good functional results and patient satisfaction.

Subungual Exostosis Systematic Review and Meta-Analysis

BACKGROUND

The coexistence of deformity of the nail bed and subungual exostosis (SE) is a frequent finding in podiatric practice in the fourth and fifth decades of life. However, it has been described by other specialists as being an uncommon osteocartilaginous tumor most prevalent during the second and third decades of life. This study attempts to determine the causes of this discrepancy.

METHODS

Two authors independently conducted a systematic bibliographic review in multiple databases, podiatry sources and others, and key words were chosen to achieve a broad search strategy. Studies reporting on epidemiology and treatment of SE lesions in lower extremities in ten or more patients were selected. Initially, 197 articles were identified through database screening, with 23 meeting all inclusion and exclusion criteria. Seven articles with the ages of all of the patients were included in the analysis of age data. A comparison was then made between the diagnostic criteria for the selected 23 articles.

RESULTS

Model results reveal that, although there are some significant differences between individual studies, the main factor tested (patient's age) was clearly significant ( F_1,5.2 = 78.12, P < .001), showing that studies coming from the podiatry speciality were conducted on individuals with a mean age of 37 years higher than in studies from other specialties. Clinical and radiologic characteristics and treatment described in the podiatry literature also contrast with those in other specialties.

CONCLUSIONS

The SE described by podiatrists, in accordance with the parameters of true exostosis, is different from Dupuytren's SE and should be considered as a different pathologic entity. The authors are working on its histologic identification.

Dystrophy of the Great Toenail by Subungual Exostosis and Hyperostosis: Three Case Reports with Different Clinical Presentations

Subungual exostoses and hyperostoses of the great toenail are a differential diagnosis of nail tumors. We present 3 cases of subungual exostosis/hyperostosis with secondary nail dystrophy: a 36- and a 37-year-old woman as well as an 8-year-old boy. Two of the 3 patients suffered from pain. The 2 female patients presented with the classic dorsolateral firm protrusion, while the child presented with bilateral nail dystrophy with lateral wall hypertrophy. In this later case, a bony ridge was identified, which is an unusual subungual, nonprotruding type of exostosis. The hypertrophic lateral walls were removed by the Vandenbos technique. In the 2 former cases, complete excision of the bony lesions was performed with a proximal block. Healing by second intention was uneventful.

Subungual exostosis of the toes: a systematic review

BACKGROUND

Subungual exostosis is a relatively common benign bone tumor that occurs in the distal phalanges of the toes and can be a source of pain and nail deformity. There is controversy about the treatment of these lesions and there are few studies that have synthesized what is known and provided meaningful information on treatment.

QUESTIONS/PURPOSES

We performed a systematic review to address the following questions: (1) What is the best surgical approach for excising these lesions? (2) What is the age range, sex distribution, and presenting symptoms of subungual exostoses and which toe is most frequently affected? (3) What complications arise from treatment?

METHODS

Two authors independently searched multiple databases (Medline, 1950-May 2013; Cochrane EBM database, and EMBASE, 1980-May 2013 provided by OVID; ACP Journal Club, 2003-May 2013; CINAHL by EBSCO, 1937-May 2013; and PubMed by NLM, 1940-May 2013), and key words were chosen to achieve a broad search strategy. We included studies on the management of toe exostoses with > 10 cases and we excluded studies that reported on upper extremity exostoses or osteochondromas. Demographic and treatment data were collected from each article by two independent authors and collated. A total of 124 abstracts were screened, and 116 articles were reviewed in full, of which 13 met the inclusion criteria.

RESULTS

Complete marginal excision through a fish mouth incision protecting the nail led to a recurrence rate of 4% and satisfactory clinical results, defined as no requirement for postoperative intervention and a satisfactory clinical appearance in 73%. Most studies provided incomplete descriptions of specific surgical techniques used. Fifty-five percent of the patients were younger than 18 years of age. A history of toe trauma before diagnosis was present in approximately 30% of the cases. Delayed diagnosis occurred in approximately 10% of the cases and onychodystrophy occurred in more than 10%.

CONCLUSIONS

There is weak evidence to guide management of subungual exostosis. Adequate wound management postexcision aiming to minimize disruption to the nail bed and matrix may prevent onychodystrophy, which is a common complication of treatment.

Protruded and nonprotruded subungual exostosis: Differences in surgical approach

BACKGROUND

In subungual exostosis surgery, repair of the damaged nail bed and surgical excision of the mass without damaging the nail bed is important. The ideal method of surgery is still unclear. This study is done to qualify the effects of different surgical methods on outcome measures in different types of subungual exostosis.

MATERIALS AND METHODS

Fifteen patients, operated with a diagnosis of subungual exostosis between January 2008 and June 2012, were evaluated. Protruded masses were excised with a dorsal surgical approach after the removal of the nail bed and nonprotruded masses were excised through a"fish-mouth" type of incision.

RESULTS

The mean age of the patients in protruded subungual exostosis group was 17.3 years (range 13-22 years) and this group consisting of seven female and two male patients. The patients were followed up for a mean of 14.1 ± 4.8 months. The mean age of the patients in the nonprotruded subungual exostosis group was 14.6 years (range 13-16 years) and consisting of six female patients. The patients were followed up for a mean of 11.6 ± 2.9 months. The results were positively affected by changing the surgical approach depending on whether or not the exostosis is protruded from the nail bed. All patients had healthy toe nails in the postoperative period without any signs of recurrence.

CONCLUSIONS

In patients with a protruded subungual exostosis, the mass should be removed by a dorsal approach with the removal of the nail and injury to the nail bed should be repaired. In patients with a nonprotruded subungual exostosis, the mass should be excised through a "fish-mouth" type incision at the toe tip without an iatrogenic damage.

An unusual case of subungal ossification in the finger

We report the case of a painless deforming subungual mass at the nail tip, progressively enlarging over three months. Radiographs showed an extra-osseous ossification. Intraoperatively this was found to be a bony mass arising from the sterile matrix. Unusual extra-osseous ossification in the finger is rare and this case highlights the need of this benign lesion to be considered when a patient presents with finger swellings.

Benign subungual tumors

A variety of benign and malignant processes may affect the subungual region; however, most are relatively rare lesions. We present a review of the current literature regarding benign tumors affecting the subungual region.

Subungual exostosis of the great toe: a case report and tumor overview

Subungual exostosis is an acquired, benign, and solitary bone tumor of the distal phalanx occurring beneath or adjacent to nail. A 18-year-old man presented with a lump, ulceration, and pain on his right big toe. This complaint was present for the past 2 years. Initially, lump and pain were present, and since the past 6 months ulceration and superadded infection occurred. Plain radiograph showed a calcified lesion that was continuous with the phalangeal cortical surface in the distal dorsal aspect of the big toe. Excisional biopsy with complete nail removal and reconstruction of the tip of the toe were done. Histopathology confirmed the diagnosis of subungual exostosis. Clinical or radiological recurrence was not observed after 26 months of follow-up. The case is reported to present the tumor overview and to highlight that the diagnosis of this benign lesion should not be missed. Clinical and radiological features allow early diagnosis and treatment thus preventing the lesion to progress to the stage of onycholysis.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

Reactive bone lesions mimicking neoplasms

Reactive lesions of bone and soft tissue can appear alarming on histologic examination because they are often cellular and have atypical (activated) cytologic features, such as distinct nucleoli and mild hyperchromasia, and mitotic activity. Reactive lesions of bone and periosteum also produce bone and cartilage matrix, resulting in confusion with osteosarcoma or chondrosarcoma. Careful attention to key cytomorphological features such as the pattern of bone formation, uniform appearance of cells, and absence of atypical mitoses should help identify the reactive nature of a lesion. Correlation with clinical and radiological findings is also imperative to avoid misclassification of the tumor because reactive lesions often arise at sites where osteosarcoma and chondrosarcoma are rare (e.g., the hand) and lack aggressive radiological features. In this review we discuss reactive lesions of bone that are commonly confused with malignant neoplasms and that the practicing pathologist is likely to encounter at some point. Several of these lesions have had characteristic chromosomal translocations documented in recent years, but continue to be included as reactive lesions based on their overall clinicopathological features.

Nail disorders in children: diagnosis and management

Nail disorders in children can be divided into seven categories. The first is physiologic alterations, which every physician should be aware of in order to reassure parents. These usually disappear with age and do not require any treatment. Among congenital and inherited conditions, the nail-patella syndrome, with its pathognomonic triangular lunula, should not be missed as recognition of the disease allows early diagnosis of associated pathologies. The most common infection is the periungual wart, whose treatment is delicate. Herpetic whitlow should be distinguished from bacterial whitlow as their therapeutic approaches differ. Dermatologic diseases encompass eczema, psoriasis, lichen planus, lichen striatus, trachyonychia, and parakeratosis pustulosa. Lichen planus, when it presents as in adults, is important to recognize because, if not treated, it may lead to permanent nail loss. Systemic or iatrogenic nail alterations may be severe but are usually not the first clue to the diagnosis. Beau lines on several fingernails are very common in children after temperature crest. Tumors are rare in children. Radiographic examination allows confirmation of the diagnosis of subungual exostosis. Other cases should undergo biopsy. Single-digit longitudinal melanonychia in children is mostly due to nevi. Its management should be tailored on a case-by-case basis. Acute trauma should never be underestimated in children and hand surgeons should be involved if necessary. Onychophagia and onychotillomania are responsible for chronic trauma.

Subungual exostosis following toe nail removal--case report

Removal of toe nail is a minor procedure that can be under ring block with no significant complications. We report the case of a young lady who developed a rapidly growing subungual exostosis on her right great toe following nail removal. Inadvertent iatrogenic injury to the nail bed and underlying phalangeal periosteum during nail removal might have triggered off rapid bone growth resulting in the large exostosis. To our knowledge, this aetiology for subungual exostosis formation has not been reported before.

Solitary asymptomatic nodule of the great toe

Subungual exostosis is a benign osteocartilaginous tumor of the ungual apparatus, particularly of the toes. It affects both sexes equally, more frequently in the second and third decades of life. We describe a 6-year-old girl who came to our attention because of the enlargement of a pinkish nodule in the distal part of the nail bed of the first toe, progressively elevating the nail plate. History, X-ray imaging and histopathologic examination led us to confirm our clinical suspicion, excluding any other possible cause of the subungual mass. The peculiar features of this clinical entity, and the possibility of effective treatment by practical surgical techniques, are discussed.

Distinct Chromosomal Rearrangements in Subungual (Dupuytren) Exostosis and Bizarre Parosteal Osteochondromatous Proliferation (Nora Lesion)

BACKGROUND

Proliferative lesions of the bone surface, such as subungual (Dupuytren) exostosis and bizarre parosteal osteochondromatous proliferation (BPOP, Nora lesion) are currently classified as reactive, proliferative processes that mimic primary neoplasms of bone.

METHODS

Cytogenetic analysis was performed on 3 subungual exostoses of the great toe and 2 BPOP lesions of the radius and ulna.

RESULTS

A balanced translocation t(X;6) was identified in all cases of subungual exostoses. The chromosomal rearrangements observed in 1 case of BPOP differed from those seen in subungual exostosis.

CONCLUSIONS

The presence of chromosomal abnormalities in subungual exostosis and BPOP suggests that these lesions are neoplastic, with a different molecular pathogenesis, and that each is a distinct clinicopathologic entity.

Subungual osteochondroma: a case report

Osteochondromas are among the most common bone tumors of the foot. However, they rarely occur in subungual locations. Clinically they appear as slow-growing masses causing deformity of the overlying nail. Here we present a case of subungual osteochondroma with characteristic clinical, radiologic, and histopathologic features. The lesion was successfully treated by total excision.

A simple and efficient surgical technique for subungual exostosis

Subungual exostosis is a benign osteochondral tumor usually involving the distal phalanx of the great toe. The lesion most frequently occurs in the second and third decades of life and is rare before the age of 10 years. There are few reports of its occurrence in children, and most of them advocate partial or complete nail excision to treat this lesion successfully. We report our experience with six children and adolescents using a simple surgical technique that involves approaching the exostosis under the nail to preserve nail coverage. Rapid recovery and excellent cosmetic appearance were achieved immediately after the operation.

Treatment of subungual exostoses by elective day case surgery

Twenty-one patients (11 female, 10 male: mean age 21.3 years) with subungual exostoses were treated with elective surgery under local anaesthetic in a dermatology day case theatre over a period of 8 years. Fifteen (71%) tumours affected the great toe, four (19%) affected other toes and two (10%) affected fingers. All received local excision with great care to remove all tumour residue from the terminal phalanx. Wounds were allowed to heal by secondary intention. Attention was paid to preoperative antiseptic procedure and postoperative analgesia. During follow-up of between 6 and 36 months (mean 17 months), there were two relapses (10%) in the first 12 months, seen in two of the younger subjects aged 9 and 13 years. One required further surgery. One further case suffered long-term dystrophy due to perioperative damage to nail matrix. Conservative and thorough treatment of this pathology can be achieved using the appropriate tools in a dermatology day case theatre.