Lichen Planus Pigmentosus Inversus: A Case Report of a Man Presenting With a Pigmented Lichenoid Axillary Inverse Dermatosis (PLAID).

Lichen planus pigmentosus is an uncommon subtype of lichen planus and lichen planus pigmentosus inversus is a rare variant of lichen planus pigmentosus. Lichen planus pigmentosus inversus typically presents as hyperpigmented patches or plaques, particularly in the intertriginous areas such as the axillae, the groin and inguinal folds, and in the submammary region. In some patients with lichen planus pigmentosus inversus, the condition can present as a pigmented lichenoid axillary inverse dermatosis (PLAID) when the lesions are in the axillae. A 49-year-old Hispanic man who had hyperlipidemia and diabetes mellitus developed lichen planus pigmentosus inversus and presented with a PLAID. Skin biopsies established the diagnosis of lichen planus pigmentosus inversus. The clinical differential diagnosis of lichen planus pigmentosus inversus includes inherited disorders, primary cutaneous dermatoses, acquired dyschromias, and reactions to topical or systemic medications. Friction in intertriginous areas has been related to the development of lichen planus pigmentosus inversus. Factors that can precipitate lichen planus pigmentosus inversus include not only topical exposure to almond oil, amala oil, cold and cosmetic creams, henna, and paraphenyldiamine but also either topical contact or consumption of mustard oil and nickel. Lichen planus pigmentosus inversus can be associated with autoimmune conditions (hypothyroidism), endocrinopathies (diabetes mellitus), and hyperlipidemia. The dyschromia found in patients with lichen planus pigmentosus inversus is frequently refractory to treatment. Initial management includes removal of potential disease triggers such as eliminating tight clothing to stop friction with the adjacent skin. Topical corticosteroids do not result in improvement; however, topical calcineurin inhibitors such as tacrolimus have been reported to be efficacious. In conclusion, inverse lichen planus and lichen planus pigmentosus inversus can present with a PLAID; whereas topical corticosteroids may be helpful to resolve inverse lichen planus lesions, topical tacrolimus may be useful to improve the dyschromia in lichen planus pigmentosus inversus.

Halo Phenomenon in Lobular Capillary Hemangioma: A Case Report of a Pyogenic Granuloma With Surrounding Cutaneous Hypopigmentation and Review of Tumors With Halo Phenomenon.

A halo phenomenon describes a skin neoplasm that is surrounded by a hypopigmented or white halo. Halo lesions have been observed in association with an epithelial neoplasm (seborrheic keratosis), a fibrous lesion (surgical scar), a keratinocyte malignancy (basal cell carcinoma), melanocytic neoplasms, and vascular lesions. Benign lesions (café au lait macules and nevi) and malignant tumors (primary and metastatic melanoma) are melanocytic neoplasms that have developed perilesional halos. Halo nevi are a commonly occurring manifestation of a halo phenomenon; however, perilesional hypopigmented halos have also been observed around nevi in patients following treatment with antineoplastic drugs, acquisition of COVID-19 (infection and vaccine), the occurrence of a visceral tumor (including not only melanoma, but also papillary thyroid carcinoma and neuroendocrine cancer of the lung), surgery (such as the excision of a primary melanoma), and Turner syndrome. A halo phenomenon has also been observed in patients with congenital (capillary malformation-arteriovenous malformation and congenital hemangioma) or acquired (angioma, eruptive pseudoangiomatosis, infantile hemangioma, and lobular capillary hemangioma) vascular lesions. In summary, a halo phenomenon can occur in association with primary lesions of various embryologic derivations. Most commonly, they have been observed in around nevi and vascular tumors. Halo lobular capillary hemangioma can be added to the list of acquired vascular lesions with the potential to develop a halo phenomenon. The preservation of melanocytes with loss of melanin pigment expression in the reported patient suggests the possibility that a post-inflammatory etiology may be responsible for the genesis of her halo lobular capillary hemangioma.

Mobile Subcutaneous Calcinosis Cutis: A Case Report of a Mobile Solitary Subepidermal Calcified Nodule on a Woman's Leg and a Review of Mobile Subcutaneous Tumors.

Calcinosis cutis describes the deposition of calcium in the dermis. A case of a 69-year-old woman with idiopathic calcinosis cutis that presented as a mobile subcutaneous nodule is described. The patient had an asymptomatic, firm, mobile subcutaneous nodule on her right lower leg of at least six months duration. The nodule could be easily moved from one location to another. An incisional biopsy was performed. Microscopic examination of the tissue specimen showed islands of basophilic calcium material in dense sclerotic dermal connective tissue establishing the diagnosis of calcinosis cutis. Mobile solitary calcification is an unusual presentation of idiopathic calcinosis cutis. In addition to idiopathic calcinosis cutis, benign mobile subcutaneous tumors have also been derived from adnexal structures of hair follicles and adipose tissue. Hence, not only idiopathic calcinosis cutis, but also subepidermal calcinosis in the ocular adnexa, proliferating trichilemmal cyst with focal calcification, and mobile encapsulated adipose tissue can present as a mobile subcutaneous nodule. The features of idiopathic calcinosis presenting as a mobile subcutaneous nodule as well as the characteristics of other benign mobile subcutaneous tumors are reviewed.

Cutaneous perivascular epithelioid cell tumor (PEComa): case report and world literature review of clinical and molecular characteristics.

Perivascular epithelioid cell tumor (PEComa) expresses melanocytic and smooth muscle markers. A man with a primary malignant cutaneous (distal left forearm) PEComa is reported. Immunohistochemistry demonstrated MiTF, HMB-45, caldesmon, desmin, and smooth muscle actin, as well as BCL1, CD10, and CD68. Next generation sequencing showed four pathogenic genomic aberrations involving BIRC3, FANCC, TP53, and TSC1 genes. His work-up was negative for metastatic disease; a wide local excision was performed. Including the reported patient, cutaneous PEComa has been described in 65 individuals: primary benign (N=58), primary malignant (N=5), and metastatic malignant (N=2). Cutaneous PEComa typically presented as a painless, slowly growing nodule of <2 centimeters on the lower extremity of a woman in her fifth decade. The neoplasms consisted of epithelioid cells, spindle cells, or both. The most reliable markers were MiTF (100%), HMB45 (94%), and NKIC3 (94%) for melanocytes and smooth muscle actin (43%) and desmin (40%) for smooth muscle. There has been no reported recurrence of a primary cutaneous benign or malignant PEComa after complete excision. Genomic alterations in malignant PEComas frequently involve TSC1 and TSC2 genes (mTOR activators), as well as TFE3 fusions. In November 2021, the FDA approved nab-sirolimus (mTOR inhibitor) for PEComas.

Frontal Fibrosing Alopecia Mimicking Alopecia Syphilitica.

Frontal fibrosing alopecia is lymphocytic scarring alopecia most commonly affecting postmenopausal women. Alopecia syphilitica, an uncommon manifestation of secondary syphilis, is characterized as a nonscarring and non-inflammatory hair loss that primarily affects the scalp. Frontal fibrosing alopecia has a classic pattern of hair loss involving regression of frontotemporal hair; it also may affect the eyebrows or other sites of the body. The typical patterns of frontal fibrosing alopecia are characterized as diffuse and linear. In addition, patients with frontal fibrosing alopecia can have atypical signs and patterns of hair loss. The atypical signs and patterns of frontal fibrosing alopecia are the androgenetic-like pattern, clown alopecia pattern, cockade-like pattern, doll hairline sign, lonely hair sign, ophiasis-like pattern, pseudo-fringe sign, and upsilon pattern. We observed a woman with a traditional pattern of frontal fibrosing alopecia whose hair loss involved the frontotemporal scalp areas; however, she also had hair loss in the occipital scalp that appeared similar to the moth-eaten alopecia of alopecia syphilitica. Her rapid plasma reagin was negative and the biopsies from her frontal scalp and occipital scalp both showed scarring alopecia consistent with frontal fibrosing alopecia. Her alopecia persisted with conservative treatment, and she returned to wearing a wig. Alopecia syphilitica-like pattern of hair loss can be added to the other atypical patterns of alopecia that may potentially be observed in a patient with frontal fibrosing alopecia.

Tinea and Tattoo: A Man Who Developed Tattoo-Associated Tinea Corporis and a Review of Dermatophyte and Systemic Fungal Infections Occurring Within a Tattoo.

Fungal infections may occur within tattoos. These include not only dermatophyte infections (tattoo-associated tinea) but also systemic mycoses (tattoo-associated systemic fungal infections). The PubMed search engine, accessing the MEDLINE database, was used to search for all papers with the terms: (1) tinea and tattoo, and (2) systemic fungal infection and tattoo. Tattoo-associated tinea corporis has been observed in 12 individuals with 13 tattoos; this includes the 18-year-old man who developed a dermatophyte infection, restricted to the black ink, less than one-month after tattoo inoculation on his left arm described in this report. Tattoo-associated tinea typically occurred on an extremity in the black ink. The diagnosis was established either by skin biopsy, fungal culture, and/or potassium hydroxide preparation. The cultured dermatophytes included Trichophyton rubrum, Epidermophyton floccosum, Microsporum canis, Microsporum gypseum, and Trichophyton tonsurans. Several sources for the tinea were documented: autoinfection (two patients), anthrophilic (tinea capitis from the patient's son), and zoophilic (either the patient's cat or dog). Three patients presented with tinea incognito resulting from prior corticosteroid treatment. Tinea appeared either early (within one month or less after inoculation during tattoo healing) in six patients or later (more than two months post-inoculation in a healed tattoo) in six patients. Injury to the skin from the tattoo needle, or use of non-sterile instruments, or contaminated ink, and/or contact with a human or animal dermatophyte source are possible causes of early tinea infection. Tattoo ink-related phenomenon (presence of nanoparticles, polycyclic aromatic hydrocarbons, and cytokine-enhancement) and/or the creation of an immunocompromised cutaneous district are potential causes of late tinea infection. Treatment with topical and/or oral antifungal agents provided complete resolution of the dermatophyte for all the patients with tattoo-associated tinea. Tattoo-associated systemic fungal infection has been reported in six patients: five men and one patient whose age, sex, immune status, and some tattoo features (duration, color, and treatment) were not reported. The onset of infection after tattoo inoculation was either within less than one month (two men), three months (two men), or 69 months (one man). The tattoo was dark (either black or blue) and often presented as papules (three men) or nodules (two men) that were either individual or multiple and intact or ulcerated. The lesion was asymptomatic (one man), non-tender (one man), or painful (one man). The systemic fungal organisms included Acremonium species, Aspergillus fumigatus, Purpureocillium lilacinum, Saksenaea vasiformis, and Sporothrix schenckii. Contaminated tattoo ink was a confirmed cause of the systemic fungal infection in one patient; other postulated sources included non-professional tattoo inoculation, infected tattooing tool and/or ink in an immunosuppression host, and contaminated ritual tattooing instruments and dye. Complete resolution of the tattoo-associated systemic fungal infection occurred following systemic antifungal drug therapy. In conclusion, several researchers favor that tattoo inoculation can be implicated as a causative factor in the development of tattoo-associated tinea; however, in some of the men, tattoo-associated systemic fungal infection may have merely been coincidental.

Multiple skin neoplasms at one site (MUSK IN A NEST): collision tumor consisting of epidermal (macular seborrheic keratosis) and dermal (lichen amyloidosis) components.

A collision tumor is a neoplastic lesion comprised of two or more tumors consisting of distinct cell populations in the concurrent location. Multiple skin neoplasms at one site (MUSK IN A NEST) is a term recently coined to describe two or more cutaneous benign or malignant tumors occurring at the same anatomic site. In retrospective studies, seborrheic keratosis and cutaneous amyloidosis have both individually been documented as a component of a MUSK IN A NEST. This report describes a 42-year-old woman who presented with a pruritic skin condition on her arms and legs of 13 years' duration. Skin biopsy results showed epidermal hyperplasia with hyperkeratosis, hyperpigmentation of the basal layer with mild acanthosis, and evidence of amyloid deposition in the papillary dermis. Based on the clinical presentation and pathology findings, a concurrent diagnosis of macular seborrheic keratosis and lichen amyloidosis was established. A MUSK IN A NEST consisting of a macular seborrheic keratosis and lichen amyloidosis is likely a more common occurrence than implied by the paucity of published cases of this phenomenon.

Cutaneous Squamous Cell Carcinoma Masquerading as a Verruca: Case Report and Literature Review of Coexisting Wart and Invasive Squamous Cell Carcinoma on the Hand.

A verruca is a human papillomavirus-associated infection of the mucosal or cutaneous epithelium. Cutaneous squamous cell carcinoma is an invasive skin cancer that commonly occurs on sun-exposed locations. Human papillomavirus infection has also been demonstrated to be a cocarcinogen, along with ultraviolet radiation, in the pathogenesis of cutaneous squamous cell carcinoma. A 63-year-old man presented with a verrucous nodule of nine months duration on his dorsal left hand. The clinical differential diagnosis included a wart and a small punch biopsy of the lesion showed a verruca. The lesion continued to enlarge and the possibility of a squamous cell carcinoma was considered. A second larger shave biopsy of the residual lesion was performed and the microscopic evaluation revealed not only a benign verruca at the lateral portion of the nodule but also an invasive squamous cell carcinoma in the center of the lesion. We hypothesize that the patient's human papillomavirus-associated wart may have contributed to the development of his cutaneous squamous cell carcinoma. Therefore, in an individual with a clinically suspected or biopsy-confirmed wart that persists despite lesion-directed treatment, additional evaluation of the lesion should be considered to assess whether an alternative or concurrent tumor, such as a cutaneous squamous cell carcinoma, is present.

An unusual case of pyogenic granuloma-like Kaposi sarcoma.

Kaposi sarcoma (KS) is not typically included in the differential diagnosis of lesions with clinical characteristics of pyogenic granuloma. However, cases of pyogenic granuloma-like Kaposi sarcoma have been reported in the literature. This variant is extremely rare and possesses clinical and histological findings consistent with both conditions. We report an elderly, immunocompetent man with pyogenic granuloma-like Kaposi sarcoma, which was clinically consistent with a pyogenic granuloma and possessed histological findings consistent with Kaposi sarcoma and pyogenic granuloma.

Acquired giant plantar fibrokeratoma: case report and review.

Acquired digital fibrokeratoma is a benign fibrous tumor usually located on the toes and fingers. A 63-year-old man with an acquired giant plantar fibrokeratoma is described. He presented with an asymptomatic exophytic nodule of ten years duration; there is no history of trauma to the site. It measured 15x10x5mm and was located on the plantar foot proximal to the third toe. Excisional biopsy established the diagnosis of fibrokeratoma. Giant acquired fibrokeratoma,has been described in 16 patients including ours: three women and 13 men. They are located on either the upper extremity (one man) or the lower extremity (15 individuals). Acquired plantar fibrokeratoma is rare. Including our patient, it has been reported in 11 patients: one woman and ten men. The woman was 13 years of age and the men ranged from 15 to 77-years-old. Plantar acquired fibrokeratomas are located on either the plantar aspect of the toes, the sole of the foot, or the heel. An excisional biopsy provided adequate treatment without subsequent recurrence of both giant and plantar fibrokeratomas.

Terbinafine-induced lichenoid drug eruption: case report and review of terbinafine-associated cutaneous adverse events.

Terbinafine is an antifungal agent used in the treatment of hair, nail, and skin dermatophyte infections. Skin side effects to terbinafine are not common. Lichenoid drug eruption is a medication-related adverse cutaneous event; the lesion morphology and pathology mimic lichen planus. A woman with onychomycosis developed a lichenoid drug eruption one week after starting terbinafine. The features of her dermatosis and the characteristics of two additional men who also experienced terbinafine-induced lichenoid drug eruption are discussed. They were receiving a daily terbinafine dosage of either 125mg or 250mg to treat onychomycosis or tinea cruris. The lichenoid drug eruption presented as diffuse or symmetric lesions within one to two weeks after starting terbinafine treatment. The extremities, chest, abdomen, and/or trunk were common sites. Less frequent locations were the lips, nails, palms, soles, and suprapubic region; lesions did not occur on the oral or genital mucosa. The eruption resolved after discontinuation of the medication (with or without treatment using topical corticosteroids, systemic corticosteroids, or both). In addition, more frequently occurring terbinafine-associated cutaneous adverse events (such as urticaria, erythematous eruptions, pruritus, acute generalized exanthematous pustulosis, subacute cutaneous lupus erythematosus, and papulosquamous conditions) are reviewed.

Case report and review of solitary cutaneous focal mucinosis: a unique primary cutaneous mucinosis unrelated to mucinosis-associated systemic diseases.

Localized deposition of mucin in the upper dermis is referred to as cutaneous focal mucinosis. Patients with this condition either present with a single skin lesion (solitary cutaneous focal mucinosis) or numerous skin lesions (multiple cutaneous focal mucinosis). A man with solitary cutaneous focal mucinosis is described and the features of this condition are reviewed. Solitary cutaneous focal mucinosis has a slight male predominance and typically presents in adults, ranging in age from 29 years to 60 years, as a nodule or papule that is flesh-colored or white and most commonly located on an extremity or the trunk. Microscopic examination shows deposition of mucin in the upper dermis; the overlying epidermis can be normal, atrophic or hyperplastic. The skin lesion is often removed at the time of biopsy. However, recurrence has not been observed when the mucin deposition is present at the edge of the biopsy or excision specimen. Although the pathogenesis of this condition remains to be established, in contrast to individuals with multiple cutaneous focal mucinosis, solitary cutaneous focal mucinosis is a unique primary cutaneous mucinosis unrelated to mucinosis-associated systemic diseases.

Tattoo-Associated Basal Cell Carcinoma: Coincident or Coincidence.

Tattoos may be associated with medical complications including, albeit rarely, skin cancer. The features of a 46-year-old man who developed a basal cell carcinoma within a tattoo on his left scapula are described and the characteristics of the other 13 patients (7 men and 6 women) with tattoo-associated basal cell carcinoma are reviewed. The tumor usually occurs on the sun-exposed skin of individuals aged 60 years and older whose tattoo has often been present for 20 years or more. The pathogenesis of a basal cell carcinoma developing within a tattoo may merely be a coincidence. However, there is supporting evidence that the tattoo and the subsequent basal cell carcinoma may be coincident events whereby either tattoo injection-associated trauma or the tattoo pigments and dyes (in their native state or after ultraviolet radiation alteration) or both have a carcinogenic impact on the development of the basal cell carcinoma at that location.

Nevus sebaceus with syringocystadenoma papilliferum, prurigo nodularis, apocrine cystadenoma, basaloid follicular proliferation, and sebaceoma: case report and review of nevus sebaceus-associated conditions.

Nevus sebaceus is a benign skin hamartoma of congenital onset that grows during puberty, and in adulthood can develop secondary benign and malignant neoplasms. The most common benign neoplasms occurring in nevus sebaceus are believed to be syringocystadenoma papilliferum, trichilemmoma, and trichoblastoma. A patient with nevus sebaceus developed not only syringocystadenoma papilliferum but also prurigo nodularis within her hamartomatous lesion; multiple biopsies were necessary to establish the diagnoses. Excision of the residual nevus sebaceus also revealed an apocrine cystadenoma, basaloid follicular proliferation, and sebaceoma. Also, it is important to select the appropriate biopsy site and size when evaluating a patient for secondary neoplasms within their nevus sebaceous. Indeed, more than one biopsy may be required if additional diagnoses are suspected.

Basal Cell Carcinoma Originating in a Tattoo: Case Report and Review of an Uncommon Complication in Tattoo Recipients.

BACKGROUND: The placement of a tattoo is a common event. Basal cell carcinoma arising from a tattoo is rare despite this neoplasm being the most common form of skin cancer. OBJECTIVE: We describe a 41-year-old man who developed a basal cell carcinoma in his tattoo and review the literature of basal cell carcinomas originating in a tattoo. METHODS: A literature search using PubMed was performed. The following terms were searched: "basal," "carcinoma," "cell," and "tattoo." The characteristics of individuals with a basal cell carcinoma originating in a tattoo were analyzed and summarized. RESULTS: A total of 13 patients (6 women and 7 men) with a basal cell carcinoma arising in a tattoo have been reported. The majority of the tumors were located on the head (6 cases, 46.2%) followed by either an upper extremity (4 cases, 30.7%) or the trunk (3 cases, 23.1%). Most of the carcinomas were asymptomatic; however, 2 patients reported pruritus associated with their tumor. Nodular basal cell carcinoma was the most common subtype diagnosed (5 tumors), followed by superficial basal cell carcinoma (2 tumors). One patient had either a pagetoid or a mixed (nodular and sclerosing) histology. The pathological variant was not described for 4 patients. CONCLUSIONS: Basal cell carcinoma arising in a tattoo is a rare occurrence. Although this occurrence may be coincidental, emerging evidence of carcinogenesis associated with tattoo pigment may suggest a causal link. Elucidating this important relationship warrants further investigation.

Histologic Characterization of Polymethylmethacrylate Dermal Filler Biostimulatory Properties in Human Skin.

BACKGROUND: Little literature exits on the mechanism of action of implanted polymethylmethacrylate (PMMA) filler. OBJECTIVE: To characterize PMMA-induced dermal extracellular matrix production in the skin. MATERIALS AND METHODS: Single-center, open-label prospective study in healthy volunteers undergoing removal of redundant skin was injected intradermally and subdermally with PMMA dermal filler (Bellafill). Punch biopsies were harvested over a time course and evaluated for the deposition of collagen-3 and procollagen-1, proteoglycans and elastin using immunohistochemistry. Blinded histopathologic readings were performed by a dermatopathologist to characterize the nature of the dermal extracellular matrix findings. RESULTS: Normal inflammatory infiltrate was exhibited at all timepoints after PMMA injection with an influx of fibroblasts and new vasculature. Tissue proteoglycans were noted within the injectate beginning at Week 1 and persisted through the study end point. Increased collagen Type 3 was evident following the first week after injection, peaked at Month 2 and diminished through Months 3 through 6. Procollagen-1 was noted at Month 1 and continued to increase in intensity and organization through the study end point (6 months). Elastin staining was inconclusive. Polymethylmethacrylate microspheres remained within the initial injection area and became encapsulated within new collagen fibers. The growth and pattern of new connective tissue mimicked a normal wound healing response. CONCLUSION: Polymethylmethacrylate-collagen gel filler stimulates collagen-3 and procollagen-1 when injected into human skin. This combination of neocollagenesis followed by microencapsulation of PMMA microspheres in the new tissue provides for long-lasting results.

Melanoacanthoma Masquerading as Melanoma: Case Reports and Literature Review.

Melanoacanthoma is a benign epithelial tumor composed of melanocytes and keratinocytes that can morphologically mimic malignant neoplasms. Two patients with melanoacanthoma that clinically masqueraded as melanoma are described: a 65-year-old African-American woman with a pigmented nodule on the right preauricular area and an 85-year-old Haitian-Creole man with a large exophytic nodule on his left lower abdomen. Melanoma was clinically suspected in both patients. Biopsies were performed, which established the diagnosis of melanoacanthoma. Complete removal of a melanoacanthoma should be considered since partial excision may result in recurrence.

Osteoma Cutis Associated with Nevus Sebaceus: Case Report and Review of Cutaneous Osteoma-associated Skin Tumors (COASTs).

Osteoma cutis is a benign cutaneous lesion characterized by the presence of bone within the dermis or subcutaneous fat. It most often develops in association with other skin lesions such as cutaneous tumors. Nevus sebaceus is a benign hamartoma of the skin that is composed of epidermal and dermal components. It most commonly appears on the scalp and may give rise to either benign or malignant secondary neoplasms. The clinical and pathologic features of a 36-year-old man with a nevus sebaceus and associated osteoma cutis are described. In addition, osteoma cutis-associated neoplasms are reviewed. Secondary osteoma cutis has been observed with both benign and malignant neoplasms as well as various non-neoplastic skin conditions. However, to the best of our knowledge, osteoma cutis has not previously been described in association with nevus sebaceus. Nevus sebaceus can now be added to the list of cutaneous osteoma-associated skin tumors (COASTs).

Melanoma Following In Vitro Fertilization: Co-incident or Coincidence?

Melanoma may occur during or after natural or in vitro fertilization-associated pregnancy. A 43-year-old woman, who had received in vitro fertilization and developed a melanoma five months postpartum is described. Some studies have not shown in vitro fertilization to increase melanoma risk; however, several investigations have observed melanoma risk to be greater in women who have had this treatment. Therefore, although a potential increased risk for melanoma has been observed in infertile women who were either pregnant before or following in vitro fertilization, whether in vitro fertilization is an etiologic risk factor in the pathogenesis of melanoma for these individuals-or is merely a coincidental event-remains to be established.

Atrophic Dermatofibroma: A Comprehensive Literature Review.

INTRODUCTION: An atrophic dermatofibroma is a benign fibrohistiocytic neoplasm. It typically presents as an asymptomatic patch with a depressed central area. METHODS: The PubMed database was used to search the following words: atrophic, dermatofibroma, elastic and fibers. The relevant papers and their references generated by the search were reviewed. Images of the clinical and pathological features of two patients with an atrophic dermatofibroma are presented. In addition, a comprehensive review of the characteristics of this unique dermatofibroma is provided. RESULTS: An atrophic dermatofibroma has been reported in 102 patients: 53 women, 11 men and 38 individuals whose gender was not provided. It typically appeared as an asymptomatic solitary patch with a central umbilication-most commonly on the shoulder or lower extremity or back-of women aged 48 years or older. Dermoscopy typically showed white scar-like patches; a patchy pigment network was also noted in some lesions. The pathology of an atrophic dermatofibroma has the same features that can be observed in a common fibrous dermatofibroma; there is acanthosis, basal layer hyperpigmentation, and induction of basal cell carcinoma-like features, hair follicle formation or sebaceous hyperplasia in the epidermis and a proliferation of spindle-shaped fibroblasts in the dermis. However, atrophic dermatofibromas also demonstrate depression of the central surface and thinning of the dermis; in many cases, the dermal atrophy is at least 50%. Elastic fibers are either decreased or absent. Similar to non-atrophic dermatofibromas, the immunoperoxidase profile of atrophic dermatofibromas is factor XIIIa-positive and cluster of differentiation 34 (CD34)-negative. The pathogenesis of atrophic dermatofibromas remains to be established. CONCLUSION: An atrophic dermatofibroma is an uncommon benign variant of a dermatofibroma. The diagnosis can be suspected based on clinical features and dermatoscopic findings. A biopsy of the lesion will confirm the diagnosis. Periodic evaluation of the lesion site is a reasonable approach to the management of the residual tumor.