Nail disorders. A review

Nail neoplasms

Nail neoplasms include all tumors occurring in the nail or periungual apparatus tissue. While some nail tumors can be similar to tumors located on the skin, others are unique. Both benign and malignant lesions can affect the nail apparatus. In particular, early malignant tumors like melanoma and squamous cell carcinoma can present similarly to onychomycosis or benign melanonychia and frequently missed by clinicians. Therefore, physicians should be aware of nail structures and the characteristics of nail tumors. Our review covers the normal nail structure and the most common nail tumors from benign to malignant.

Nail unit tumors: a study of 234 patients in the dermatology department of the "Dr Manuel Gea González" General Hospital in Mexico City

BACKGROUND

The frequency of nail unit tumors is not well known because they are often misdiagnosed, and the clinical appearance of benign and malignant tumors is not characteristic.

PATIENTS AND METHODS

A total of 234 patients from the dermatology department of a general hospital in Mexico City were included in this study, from January 1982 to November 2006.

RESULTS

The tumors most frequently diagnosed were fibrous tumors (29.05%), osteocartilaginous tumors (21.79%), and myxoid pseudocysts (11.96%). Malignant melanoma occupied the fourth place (9.82%), and the second most frequent malignant tumor was squamous cell carcinoma (SCC; 4.70%). Among other tumors were glomus, neurofibromas, giant cell tumors of tendon sheath, and pyogenic granulomas. The nail plate was affected in 46.5% of the cases studied.

CONCLUSION

This study in a Mexican population sheds light on the frequency and the alterations produced by nail unit tumors, which we must keep in mind for a more accurate diagnosis.

Common nail tumors

Nail abnormalities are varied and numerous. They include warts, keratoacanthomas, onychomatricomas, fibrokeratomas, osteochondromas, tumors (ie, glomus, giant cell, Koenen's, and others), and Bowen's disease. Although the gravity of these conditions may vary, prompt diagnosis and treatment is of the utmost importance. This article discusses the most common defects associated with the nail unit and its surrounding tissue, as well as the differential diagnosis and treatment of these conditions.

Brittle nail syndrome: a pathogenesis-based approach with a proposed grading system

Brittle nail syndrome is a heterogeneous abnormality, characterized by increased fragility of the nail plate. Brittle nails affect about 20% of the population and women are affected twice as frequently as men. The vast majority of patients experience brittle nails as a significant cosmetic problem and a substantial number indicate that these nail abnormalities are painful, impair daily activities, and may have a negative impact on occupational abilities. Pathogenic factors leading to brittle nails are factors that impair intercellular adhesion of the corneocytes of the nail plate or factors that cause a pathologic nail formation by involving the matrix. Clinical features of brittle nail syndrome are onychoschizia and onychorrhexis: the impairment of intercellular adhesive factors of the nail plate is expressed as onychoschizia, whereas the involvement of the nail matrix is expressed as onychorrhexis. Although impairment of life quality has not been evaluated for patients with brittle nail syndrome, the reduction of life quality in other nail problems has been studied and is evident. A proposed scoring system of key features of brittle nails is presented, and therapeutic approaches focussed on the pathogenic factors are discussed.

Subungual Osteochondroma: Clinical and Radiologic Features and Treatment

BACKGROUND

Subungual osteochondromas are relatively rare.

OBJECTIVE

The objective was to evaluate the clinical, histologic, radiologic, and therapeutic features of subungual osteochondroma.

METHODS

We retrospectively analyzed 27 cases of subungual osteochondroma evaluating the clinical manifestations, the radiologic and histologic features, and the treatment.

RESULTS

There were 20 females and 7 males. The first toe was the most commonly involved. Previous trauma was recalled in 40.7% of the cases. Subungual osteochondromas appeared as firm, exophytic tumors beneath the ungual plate. Twenty-five patients had pain. The radiologic films demonstrated the presence of a juxtaephiphyseal radiodense cap surrounded in some cases by cortical bone. A Dubois-like excision was performed to expose the tumor and cut it through the base, followed by curettage of the bony bed. Radiologic controls were taken 30 and 60 days after surgery and in cases of symptomatology. There were three cases of recurrence and two cases of incomplete excision.

CONCLUSIONS

Subungual osteochondroma should be distinguished from other subungual masses. The diagnosis of subungual osteochondroma is clinicoradiologic.

Tumors of the perionychium

Tumors of the perionychium are often subtle and difficult to diagnose. Because they are somewhat uncommon, the early symptoms of these tumors, which may include vague pain, local swelling, nail discoloration, nail deformity, or drainage, may be mistaken for signs of infection and/or trauma and therefore treated with topical or oral antibiotics for some time. Functionally important in enhancing fingertip sensation, protection, and manipulating fine objects, the perionychium is continuously subject to day-to-day trauma and injury that can alter the natural contours and growth patterns of the nail plate. Bacterial, viral, or fungal infections can incite swelling, pain, and distortion of the perionychium as well. Both infection and trauma, then, can mask underlying tumors or growths that would delay their diagnosis. A delay in treatment can be devastating if the growth of the perionychium happens to be malignant. Therefore, a general understanding of the signs and symptoms of the perionychium tumors is needed by all physicians and surgeons treating nail problems.

A case of subungual osteochondroma

Subungual osteochondroma is a rare form of benign bone tumor characterized by distinctive histopathological and radiological findings. The major clinical manifestation is a firm mass with tenderness. It must be differentiated from other similar diseases such as subungual exostosis, glomus tumor, and enchondroma to determine the proper surgical procedure. A 13-year-old boy had a history of a growing tender mass on the right third toe which recurred after simple excision. He was treated by careful dissection and total excision under local anesthesia. Histologic findings included a trabecular bone formation covered with hyaline cartilage cap and were compatible with osteochondroma.

Subungual exostosis: case report and review of the literature

Subungual exostosis is typically a benign, acquired tumor of cartilaginous bone occurring on the medial surface of the distal hallux. A 16-year-old boy with subungual exostosis of his left great toe is presented. We evaluated the English language literature on this topic from 1857 to 1994; including our patient, 312 cases have been described. The diagnostic characteristics (histologic and radiologic), etiologic features, and therapeutic management were reviewed. Subungual exostosis more commonly affects women than men in a ratio of 2:1. Most lesions occur in the early twenties; however, a minimum of 51 (16%) of the 312 cases of subungual exostoses appeared in children 18 years of age or younger. Seventy percent of lesions occurred on the first hallux. There was frequently an association with trauma. The diagnosis of subungual exostosis may be suspected from the clinical presentation and confirmed with radiographic examination. The treatment is surgical.

Subungual exostosis

The author describes subungual exostoses as well as their differential diagnoses. Clinical and radiologic features are illustrated. Surgical excision is recommended, following partial toenail avulsion, in the majority of symptomatic cases.

Dermatologic surgery of the hand. General principles and avoiding complications

Dermatologists and dermatologic surgeons are frequently presented with significant pathology of the hand. Because the hand plays such a unique and important role in man's everyday life, preservation and restoration of its form and function is critical. The hand is both powerful and extremely delicate. Before performing any procedures in this area, dermatologists and dermatologic surgeons must have a clear understanding of the cutaneous and deep anatomy of the hand and digits, as well as a thorough knowledge of the disease process being treated and the modality being used. This article reviews the intricate anatomy, the proper hemostasis and anesthesia, and many of the complications seen in dermatologic surgery and procedures of the hand, digits, and nails. With appropriate preoperative evaluation and precautions, many dermatologic procedures may be safely performed on the hand.

Tumors of the nail unit

Tumors of the nail unit are often initially misdiagnosed or diagnosed later in their course than their skin counterparts. This is probably because the nail can obscure the lesion or many nail tumors mimic inflammatory dermatoses of the nail unit. Both benign and malignant tumors of the nail unit are described.

Nail biopsy. Indications and methods

Nail biopsy is a safe and useful diagnostic procedure for many nail disorders when routine clinical and laboratory methods fail to produce a diagnosis. Prerequisites for nail biopsy are an understanding of the surgical anatomy of the nail, adequate anesthesia and hemostasis, and a nail abnormality for which histopathology can provide the diagnosis. Indications and methods for nail biopsy vary according to the site and type of pathology in the nail unit. Nail bed and perionychial biopsies can be performed easily and with minimal scarring. They are most commonly used to diagnose tumors as well as infectious and inflammatory disorders of the nail. The most important reason to biopsy the nail matrix is to make or exclude the diagnosis of melanoma in a patient with longitudinal melanonychia. Great care must be taken in nail matrix biopsy to minimize the risk of permanent nail dystrophy.

Subungual leukemia cutis

A 79-year-old man had generalized humping of the nails and subungual tumors involving several fingers and the left big toe. Findings on histologic study of the tumor, together with the pattern on the peripheral blood smear, established the diagnosis of chronic lymphocytic leukemia. To the best of our knowledge, this is the first reported case of chronic lymphocytic leukemia involving the subungual area. The authors' observation emphasizes the importance of taking a biopsy specimen in the differential diagnosis of subungual tumors.

Nail involvement in osteoarthritis

Two cases of nail involvement associated with primary interphalangeal osteoarthritis of the hand, including leukonychia and longitudinal nail ridge, are reported. Osteoarthritic changes of the distal interphalangeal joints may cause nail lesions by exerting direct pressure on the nail matrix or by interfering with local blood flow. Moreover, inflammation of the Heberden's nodes is often present and seems to participate in the development of nail alteration. In our patients, leukonychia disappeared after local steroidal anti-inflammatory treatment of the osteoarthritic node and longitudinal nail ridge disappeared after treatment with nonsteroidal anti-inflammatory agents.

Nail disease and dermatology

Onychology (the study of nails) is an important area in dermatology. We discuss the dermatologists' opportunity to educate their patients and colleagues about nail disorders, review the diagnostic techniques for evaluating nails, and describe some of the possible topics for additional research.

Subungual keratoacanthoma in the hand

A subungual keratoacanthoma of the thumb with a 5-year follow-up is reported. Recurrence after initial curettage necessitated amputation of the terminal phalanx as definitive treatment. The 22 subungual keratoacanthomas of the hand reported in the literature are reviewed. Although conservative treatment sparing the digit in the form of excision and curettage is recommended as the initial treatment of choice, this uncommon benign, but aggressive, lesion of the nail bed may require amputation of the involved phalanx as definitive treatment.

Papulosquamous diseases: a review

Papulosquamous diseases are a heterogeneous group of disorders whose etiology primarily is unknown. The nosology of these disorders is based on a descriptive morphology of clinical lesions characterized by scaly papules and plaques. The major entities in this group include psoriasis, parapsoriasis (including pityriasis lichenoides et varioliformis acuta), lichen planus, lichen nitidus, lichen striatus, pityriasis rosea, pityriasis rubra pilaris, seborrheic dermatitis, and the Gianotti-Crosti syndrome. Many other conditions may become papulosquamous and should be considered in the differential diagnosis.

Onycholysis of the fingernails: evaluation and management

Onycholysis (ONY) of the fingernails is a common disorder that is diagnosed with ease but often managed with great difficulty. The full spectrum of causes is broad and not always readily apparent. In this review, an approach to the evaluation and management of ONY is offered.

Nail changes secondary to systemic drugs or ingestants

Systemic drugs often affect the nails. These changes range from mild pigmentation abnormalities to nail shedding and matrix scarring. The purpose of this article is to provide a handy reference for the physician who is confronted with nail disorders that may be due to systemic drugs or ingestants.

Diseases of the nails. How to recognize and treat them

Diseases of the nails are relatively common complaints among patients. Manifested by color changes, nail dystrophy, and inflammation of subungual and periungual tissues, they have a number of causes. In this concise and practical article, Dr Gunnoe discusses several of the most common nail disorders--their recognition and treatment, as well as their significance in pointing to underlying internal disease.

The transmission of optical radiation through human nails

The transmission of optical radiation in the wavelength range 300-600 nm through thirteen human toenails obtained at autopsy was examined. The total transmitted radiation at fifteen different wavelengths was measured using an irradiation monochromator in conjunction with an integrating sphere and photodiode. A correction was included for fluorescence radiation from the nails. The nails exhibited decreasing transmission of optical radiation in the wavelength region 600-300 nm. These findings may be helpful in the understanding of photo-onycholytic reactions and in the design of suitable regimens for the treatment of psoriatic nail changes.

Squamous-cell carcinoma of the nail bed

Carcinoma of the nail bed is rare. Two patients with squamous-cell carcinoma are presented. We recommend biopsies for recalcitrant lesions of the nail bed and treatment by amputation or Mohs' surgery if carcinoma is found.

Dilantin digital defects

Diphenylhydantoin (phenytoin) is a widely used drug with multiple adverse effects, several of them cutaneous. Prenatal exposure to hydantoins may result in a spectrum of structural, developmental, and behavioral changes known as the fetal hydantoin syndrome (FHS). A patient with the dysmorphic characteristics of FHS had unusual hyperpigmentation of several fingernails, a finding which has not been described in other patients with FHS. We propose a mechanism for the dysmorphic action of phenytoin on the developing fetus, consonant with the known effects of hydantoins on collagen metabolism.