Subungual keratoacanthoma

Subungual keratoacanthoma is a very rare condition that varies in its clinical presentation from keratoacanthoma in other localizations. It is a painful lesion that fails to regress spontaneously and shows more vertical growth. On X-ray examination destruction of the underlying bone, caused by pressure, can be seen. It may be difficult to distinguish subungual keratoacanthoma from other subungual tumors, especially squamous cell carcinoma; therefore clinical and histological data should be taken into consideration.     

Subungual keratoacanthoma—a report of four cases and review of the literature

Subungual keratoacanthoma is a rare benign neoplasm which most commonly occurs in middle-aged Caucasians. It usually presents as a painful, rapidly growing lesion of the terminal phalanx. Radiography consistently demonstrates a well-defined cup-shaped erosion of the underlying bone. Clinically, subungual keratoacanthoma must be distinguished from subungual squamous carcinoma. We report four further cases and discuss the literature.     

Subungual keratoacanthoma. Report of a case and review of the literature

Subungual keratoacanthoma (SUKA) is an uncommon and clinically distinctive tumor of the nail bed. It can easily be confused with well-differentiated subungual squamous cell carcinoma. Distinguishing features of SUKA include pain, rapid growth, and early underlying bony destruction. Unlike keratoacanthomas arising from sun-exposed skin, SUKAs seldom resolve spontaneously and are more locally destructive. Of 18 cases reported in the literature, five patients have developed recurrent disease, all within five months of the initial surgery. We describe a patient with SUKA initially treated by curettage followed two days later by a conservative amputation that revealed conspicuous residual keratoacanthoma. The deep, burrowing tendency of SUKA and the intimate association with underlying bone may explain the reported tendency for recurrence after curettage.     

Subungual Pigmented Nevus: Evaluation of DNA Ploidy in Six Cases

The discrimination between subungual pigmented nevus and subungual melanoma in situ is still a clinical problem. We measured DNA ploidy in six cases of subungual melanotic lesions which exhibited the features of subungual pigmented nevus or lentigo simplex histologically. Five cases presented a diploid pattern with or without a slight increase of hyperdiploid cells. One case presented a polyploid pattern; it also exhibited histologically abnormal melanocytes with large nuclei and pigment-filled elongated dendrites. The DNA ploidy pattern and histologic features suggest that the lesion of this latter case contains abnormal melanocytes which probably have the potential to undergo a malignant transformation into a subungual melanoma. DNA ploidy analysis, therefore, is likely to provide information for evaluating the biologic behavior of subungual melanotic lesions.     

A subungual nevus in a Filipino child

A 2.5-year-old Filipino girl with a progressively growing, black, subungual lesion is described. A biopsy was performed because of the progressive increase in size of the lesion and its periungual involvement. Histologic examination revealed a junctional nevus. To our knowledge, this represents the first report of subungual nevus in a Filipino child. The need for histologic diagnosis prior to definitive surgery cannot be overemphasized.     

Subunguales Plattenepithelkarzinom

A 63-year-old patient presented with a 12-month history of a subungual tumor on the right middle finger. The patient had had a similar lesion involving his left index finger 5 years ago, which was identified as a subungual squamous cell carcinoma. Except for hypertension and hyperlipidemia, the patient was in good health. Ablation of the nail plate, the nailbed and the matrix was performed. Histopathology confirmed another subungual squamous cell carcinoma. The patient received a full thickness skin graft. Subungual squamous cell carcinomas are among the most frequently reported types of subungual malignancies. However, subungual squamous cell carcinomas arising in more than one digit have been reported only rarely. The cause of subungual squamous cell carcinoma has not been clearly identified. Subungual squamous cell carcinoma has been associated with radiation, chronic infection, arsenic ingestion, HPV infection and trauma. None of these could be identified in our patient.     

A Case of Solitary Fibrous Tumor of Subungual Region

Solitary fibrous tumor (SFT) is a relatively uncommon mesenchymal neoplasm that usually arises in the pleura, but also has been reported in numerous extrapleural locations, including cutaneous site. The skin lesion presents as a circumscribed nodule or tumor, mainly on the head and neck. A 41-year-old male presented with 6 months history of nail lesion without symptom on the left third finger. The lesion is slightly yellowish discoloration with subungual erythematous nodule and distal onycholysis. Biopsy specimen from the nail lesion showed the spindle cells form patternless pattern with hypercellular and hypocellular area. And small blood vessels and dilated vascular spaces were present. The result of special stain for specimen showed that positive for CD34, Bcl-2, and CD99 but negative for S-100, FactorXIIIa, and smooth muscle action. Recognition of this uncommon location of SFT is important because of possible confusion with other subungual tumors, including glomus tumor, fibroma and other fibrohistiocytic tumors like dermatofibrosarcoma protuberans, superficial acral fibromyxoma and cellular digital fibroma. Here in, we report a case of SFT of subungual region. We think this case is interesting because of uncommon location and may be helpful to more understand the character of this disease.     

甲下神经鞘瘤

报告1例发生在右足第2趾甲下的神经鞘瘤。患者男，70岁。右足第2趾肿胀疼痛1个月余，皮肤科检查见右足第2趾甲板不全脱落，末端肿胀，中央可见质软的半透明肿块。肿块组织病理及免疫组化染色检查提示为神经鞘瘤。     

Pigmented nail with atypical melanocytic hyperplasia

We report two cases showing black discoloration of the thumb nail which were histologically found to be acral lentiginous melanoma (ALM) in situ. A pigmented subungual lesion is more frequently malignant than benign and it is generally believed that diagnosis of subungual melanoma during the radial-growth phase is very difficult. Our cases are particularly interesting because atypical melanocytic hyperplasia was confined to the epidermis despite the lesion being present for a long time.     

Subungual amelanotic melanoma

We describe a 76-year-old white male with subungual amelanotic melanoma. The lack of pigmentation of the lesion may cause misdiagnosis and aggravate its poor prognosis.     

Subungual Soft Tissue Chondroma with Nail Deformity in a Child

Soft tissue chondroma is a rare benign tumor of the cartilage. It occurs commonly in distal extremities of middle‐aged patients. It is usually asymptomatic and grows slowly, making early diagnosis difficult. We report a 10‐year‐old patient with a 1‐year history of a subungual soft tissue chondroma on her left fifth finger. The lesion arose from nail bed and distal nail matrix, resulting in nail dystrophy. Magnetic resonance imaging revealed a soft tissue tumor in the subungual region and soft tissue chondroma was diagnosed, based on histopathologic findings. Dermatologists should consider soft tissue chondroma in the differential diagnosis of subungual tumors of children.     

Solitary nodule of the great toe

We describe a 21-year-old woman with a subungual exostosis exhibiting both skin and nail findings. The patient presented with a firm, flesh-colored, nontender, subungual nodule in the distal nail bed of the great toe. Radiographic examination revealed focal calcification of the nodule, with direct communication to the underlying phalanx. Subungual exostosis should be considered in the differential diagnosis of any digital mass. Surgical excision, followed by curettage of the base, is the treatment of choice.     

Localized multinucleate distal subungual keratosis

Isolated distal subungual keratosis refers to a clinical monomorphic lesion involving one digit, but presenting different histological patterns. Among these, in four similar cases, we have observed the presence of multinucleate cells in localized distal subungual keratosis without an intervening granular layer, and without any clinical evidence of Darier's disease. To our knowledge, this constellation of anatomical and clinical features has not been reported previously.     

Subungual glomus tumour: evaluation of ultrasound imaging in preoperative assessment

For an evaluation of the preoperative assessment of subungual glomus tumours, a non-invasive examination of the lesion is desirable. Previous studies, however, have not clearly demonstrated these findings. We examined two cases of subungual glomus tumours and applied the approximately 5-14 MHz broadband B-mode and C-mode ultrasound imaging methods combined with Color Doppler imaging (CDI) and B-flow imaging (BFI) to clarify the significance of the preoperative assessment. We confirmed the tumour's localization, size and depth, using B-mode and C-mode imaging; and tumour vascularity using CDI and BFI. BFI is a newly developed ultrasound technique that enhances the B-mode imaging quality of the blood flow, including high-frame-rate and high-spatial-resolution imagings. BFI revealed the exact fine blood vessels within the subungual small tumour with no blooming compared to CDI. Our results indicate that these ultrasound scanning imagings are non-invasive and nonionizing evaluation methods, and that an accurate preoperative diagnosis using these methods will result in more effective surgical excision and relief.     

Acral lentiginous melanoma mimicking benign disease: the Emory experience

BACKGROUND: Plantar and subungual melanoma exhibits a higher misdiagnosis rate relative to other anatomic sites. Misdiagnosis and delay in diagnosis are statistically associated with poorer patient outcome. Awareness of atypical presentations of acral melanoma may, thus, be important to decrease misdiagnosis rates and improve patient outcome. METHODS: We conducted a retrospective case review of plantar or lower-extremity subungual melanoma performed at Winship Cancer Center, a tertiary care, referral center affiliated with Emory University, between 1985 and 2001. RESULTS: A total of 53 cases of plantar or lower-extremity subungual melanoma were identified. Of 53 cases with a final diagnosis of melanoma, 18 were initially misdiagnosed. Misdiagnoses included wart, callous, fungal disorder, foreign body, crusty lesion, sweat gland condition, blister, nonhealing wound, mole, keratoacanthoma, subungual hematoma, onychomycosis, ingrown toenail, and defective/infected toenail. Of the 18 misdiagnosed cases, 9 were clinically amelanotic. CONCLUSION: Awareness that amelanotic variants of acral melanoma may assume the morphology of benign hyperkeratotic dermatoses may increase the rate of correct diagnosis and improve patient outcome.     

Congenital subungual nevus

A 4-month-old infant with a congenital, darkly pigmented, macular lesion involving the subungual and periungual areas of the right ring finger is described. The lesion was excised when the infant was 6 months old in order to rule out a congenital pigmented nevus as well as a congenital acrolentiginous melanoma. Histopathologic examination revealed a compound nevus. Nevi in this location are very rare in Caucasians at any age and should probably be excised to rule out malignant melanoma.     

Tungiasis

A 24-year-old man developed slow-growing lesions on subungual and plantar areas that appeared a few weeks after returning from a trip to South America. The diagnosis of tungiasis was established by microscopic examination of a lesion. Tungiasis is rarely seen in non-endemic areas.     

A Rare Case of Subungual Melanoma

A 51-year-old male presented with blackish discoloration of nails of 10 months duration. Examination revealed black dystrophic left thumb finger nail. Detailed examination showed a mass under the dystrophic nail. Hutchinson sign was positive. Histopathology revealed characteristic features of melanoma. A detailed evaluation revealed no features of local or distant metastasis. The entire lesion was then removed surgically along with disarticulation at the interphalangeal joint. Resection-free margin was confirmed. This case is being reported for the rare occurrence of subungual melanoma in the Indian population and also for presentation with a long history of lesion with no evidence of metastasis.     

Sclerosing lymphangitis of the penis

Nonvenereal sclerosing lymphangitis is a rare penile lesion consisting of a minimally tender, indurated cord involving the coronal sulcus and occasionally adjacent distal penile skin. This disorder most often occurs after vigorous sexual activity and resolves spontaneously. However, as evidenced by 2 of the 3 cases reported, this condition also may be associated with underlying sexually transmitted disease that necessitates specific therapy.     

Renal cell carcinoma metastatic to the thumb: a case report and review of subungual metastases from all primary sites

Subungual metastatic cancer from any primary site is rare. Only seven cases from primary renal cell carcinoma have previously been reported. We now describe a further example of this condition and review its clinical features, radiographic findings and pathological changes. The diagnosis of subungual metastasis should be considered in any patient with metastatic cancer who develops a new lesion of the distal phalanx.