Spontaneous regression of subungual keratoacanthoma with reossification of underlying distal lytic phalynx

Surgery for benign nail tumor

The vast majority of tumors in the nail apparatus have a different clinical presentation and course from their equivalents on the skin. Some, such as onychomatricoma and onychopapilloma, are unique to the nail and others, such as superficial acral fibromyxoma, have a tropism for the nail apparatus. As a rule, benign lesions respect the general architecture of the nail apparatus, whereas malignant tumors are destructive. Treatment is always surgical and good knowledge of the anatomy and the procedures is mandatory in order not to induce postoperative nail dystrophy.

Ungual Keratoacanthoma With Features of Regression

ABSTRACT

Ungual keratoacanthoma (UKA) is an infrequent tumor. Different from keratoacanthoma in other parts of the skin, UKA rarely regresses, and grows aggressively with common destruction of the subjacent phalanx. Reported cases of UKA with features of regression are exceptional, and even dermatopathologists with reputed experience in nail pathology admit to having seen very few cases. We herein report a case of a 77-year-old man who presented a painful subungual lesion on the second finger of the right hand. An x-ray showed evidence of erosion of the subjacent distal phalanx. The patient was highly concerned about the lesion and rejected conservative treatment preferring amputation of the distal phalanx. The histopathologic examination revealed a UKA with features of regression.

Treatment Options and Outcomes for Squamous Cell Carcinoma of the Nail Unit: A Systematic Review

BACKGROUND

Nail squamous cell carcinoma (nSCC) is the most common nail unit malignancy. However, no studies to date have evaluated treatment options for nSCC based on recurrence data while controlling for invasion.

OBJECTIVE

To identify temporal trends in nSCC treatment modalities and compare treatment outcomes based on invasion.

METHODS AND MATERIALS

The authors performed a systematic review of articles published on PubMed, MEDLINE, and Scopus from inception to April 2020 reporting treatment of nSCC. The primary outcome was disease recurrence.

RESULTS

Reports of nSCC treatments have increased in the past decade. Mohs micrographic surgery (MMS) is the most common treatment reported overall. The lowest recurrence rates for in situ nSCC were seen with wide surgical excision (WSE) and MMS. For invasive disease, the recurrence rates were lowest with amputation, MMS, and WSE.

CONCLUSION

Complete surgical excision of nSCC with either WSE or MMS is associated with lower recurrence rates than limited excision and nonsurgical therapies, regardless of degree of invasion. The prognostic significance of in situ versus invasive disease remains unclear. Confirmation of complete excision may improve outcomes. Digital amputation is indicated for nSCC with bone invasion. Prospective studies and randomized controlled trials are needed to directly compare surgical modalities for nSCC.

Relationship between Human Papilloma Virus and Subungual Keratoacanthoma: Two Case Reports and the Outcomes of Surgical Treatment

Subungual keratoacanthoma (SUKA) is a rare form of keratoacanthoma, with the majority of the lesions appearing as rapidly growing, painful hyperkeratotic masses located under the distal nail plate of the thumb. In some cases, SUKA causes damage to the underlying bone. The first case presented here was treated by surgical excision alone, and human papilloma virus (HPV) type 6 was detected in the tissue samples. The second case was treated by surgical excision plus curettage; however, HPV was not detected, and tumor cells were not found in the curettage material. There was near complete improvement in both the clinical appearance and the distal phalanx destruction, with no recurrence at the final follow-up in either patient (30 and 14 months, respectively). Overall, simple excision alone or in combination with curettage seemed to be sufficient in the treatment of SUKA; however, the etiopathogenetic role of HPV in SUKA remains controversial, as in its classical form.

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.