Sebaceous hyperplasia overlying a dermatofibroma

Epithelial changes overlying dermatofibromas are well recognized. The presence of sebaceous differentiation overlying a dermatofibroma is unusual. We report two patients with sebaceous hyperplasia overlying a dermatofibroma and discuss possible mechanisms for induction of the epithelium and adnexa by the mesenchyme in a dermatofibroma.     

Plate-like sebaceous hyperplasia overlying dermatofibroma

Epidermal hyperplasia, sometimes with primitive hair follicle-like differentiation, is a characteristic finding overlying dermatofibroma. We here report plate-like sebaceous hyperplasia overlying a dermatofibroma. Such changes are interpreted as a result of inductive epithelial effect by the dermatofibroma on the overlying epidermis.     

Sebaceous hyperplasia: a clue to the diagnosis of dermatofibroma

We describe a man with an indurated lesion on his upper back that showed a dermatofibroma with overlying sebaceous hyperplasia. Characteristic dermal features of a dermatofibroma may be sparse or absent in a lesional specimen that has been submitted subsequent to a superficial shave biopsy. Hyperplasia of sebaceous glands in a nonfacial lesion is a histologic feature that should prompt the search for a dermatofibroma in the underlying dermis.     

Basal cell carcinoma overlying a dermatofibroma

The epidermis over a dermatofibroma may show changes that range from simple hyperplasia to the proliferation of basaloid cells, which can become morphologically indistinguishable from basal cell carcinoma. The existence of a true basal cell carcinoma overlying a dermatofibroma is infrequent. These basaloid proliferations have usually been considered to be the result of the inductive effect of the fibrohistiocytic proliferation of the dermatofibroma on the epithelial cells of the hair follicle; therefore, it would be a reactive phenomenon and not truly neoplastic. We describe a case of dermatofibroma that presented with a basaloid proliferation identical in appearance to a basal cell carcinoma on the overlying epidermis.     

Multiple clustered dermatofibroma presenting in a segmental distribution

Multiple dermatofibromas is a rare entity consisting of more than fifteen lesions. Multiple clustered dermatofibroma is a distinct variant of multiple dermatofibromas and is defined as a well‐demarcated plaque composed of individual dermatofibromas. We report a 16‐year‐old boy with multiple clustered dermatofibroma in a segmental distribution, which has previously not been reported in the literature.     

Lentiginous Melanocytic Hyperplasia Overlying Dermatofibroma

There are occasional reports of proliferative epidermal changes overlying dermatofibromas. We report the first case to our knowledge of a dermatofibroma with overlying lentiginous melanocytic hyperplasia.     

Squamous cell carcinoma in situ overlying dermatofibroma

There are occasional reports of benign proliferative epidermal changes overlying dermatofibromas and rare cases of invasive basal cell carcinoma. We report the first case to our knowledge of a dermatofibroma with overlying in situ squamous cell carcinoma.     

In vitro examination of cell proliferation in dermatofibroma and in the overlying epidermis

Summary In nine typical cases of dermatofibroma autoradiographic methods were used to examine the proliferative activity in the tumor and in the overlying epidermis. The number of DNA-synthesizing cells in the dermal nodular lesions was extremely low (0–0.1%). In seven of nine skin lesions acanthosis was to be seen in the overlying epidermis. The quantity of DNA-synthesizing cells in the epidermis overlying the dermatofibroma was not related to the thickness of the epidermis and remained independent, whether the predominant element in the tumor is fibrillar or cellular. In this study we were able to demonstrate the existence of a direct relation between the degree of epidermal proliferation and the distance between the tumor and the epidermis. The duration of DNA-synthesis was constant.Herrn Prof. Dr. G. W. Korting zum 60. Geburtstag     

Plaque‐like dermatofibroma: A distinct and rare benign neoplasm?

Unusual large dermatofibromata are reported in a 40-year-old man and a 48-year-old man, who both presented with plaques on a lower limb. The largest plaque in each case was well-defined, reddish brown, indurated and measured 50 mm x 30 mm and 70 mm x 40 mm, respectively. Several satellite lesions were present around the large plaques. Dermoscopic examination showed diffuse homogenous pigmentation in the absence of other diagnostic criteria for dermatofibroma. Light microscopy of biopsies from each patient displayed similar features. There was a dermal proliferation of fibrohistiocytic cells that entrapped intervening thickened collagen fibres. The overlying epidermis was acanthotic, and in some instances this showed basal hyperpigmentation. There was no evidence of malignancy. Immunohistochemical staining was positive for Factor XIIIa and negative for CD34. Based on the histological findings, a diagnosis of dermatofibroma was made for each of these cases. Fewer than 20 adult cases of large dermatofibroma of this scale, designated giant dermatofibroma, have been reported to date; and only two have shown a plaque-like appearance, the remainder being pedunculated. The authors propose plaque-like dermatofibroma as a variety of large dermatofibroma distinct to pedunculated giant dermatofibroma.     

Immunohistochemical analysis of S100-positive epidermal Langerhans cells in dermatofibroma

Dermatofibroma is a dermal fibrohistiocytic neoplasm. The Langerhans cells are the immunocompetent cells of the epidermis, and they represent the first defense barrier of the immune system towards the environment. The objective was to immunohistologically compare the densities of S100-positive Langerhans cells in the healthy peritumoral epidermis against those in the epidermis overlying dermatofibroma (20 cases), using antibodies against the S100 molecule (the immunophenotypic hallmark of Langerhans cells). The control group (normal, healthy skin) included ten healthy age and sex-matched individuals who underwent skin biopsies for benign skin lesions. A significantly high density of Langerhans cells was observed both in the epidermis of the healthy skin (6.00 ± 0.29) and the peritumoral epidermis (6.44 ± 0.41) vs. those in the epidermis overlying the tumor (1.44 ± 0.33, p < 0.05). The quantitative deficit of Langerhans cells in the epidermis overlying dermatofibroma may be a possible factor in its development.     

Multiple clustered dermatofibroma: case report and review of the literature

The presence of multiple dermatofibromas is rare and is defined as more than 15 lesions. Multiple clustered dermatofibroma (MCDF) is a distinct entity with only 12 reported cases in the literature. MCDF occurs in healthy individuals of both sexes in the first to third decades on the lower half of the body and portends an excellent prognosis. On histology, MCDF is consistent with benign dermatofibromas. We report a 31‐year‐old healthy Hispanic woman with a 14‐year history of slowly progressive MCDF located on her right hip initially misdiagnosed as dermatofibrosarcoma protuberans. We believe this case represents the 13th report of MCDF in the literature and the second from North America. Gershtenson PC, Krunic AL, Chen HM. Multiple clustered dermatofibroma: case report and review of the literature.     

Dermatofibroma: a possible model of local fibrosis with epithelial/mesenchymal cell interaction

Dermatofibromas are benign dermal nodules usually seen on the extremities; however, whether a dermatofibroma is a reactive fibrous hyperplasia or a true neoplasm is still unclear. Fibrous type dermatofibromas might be regarded as the symptom of local fibrotic processes and thus present a possible model of local fibrosis. Interaction between proliferated dermatofibroma fibroblasts and overlying elongated epidermis suggests a relationship between keratinocytes and mesenchymal cells. We herein describe current insights into the pathogenesis of dermatofibromas and explore the possible involvement of immunocytes around fibroblasts and effector cells which play an important role in the development of dermatofibromas.

Conflicts of interest

None declared     

Differentiation of the basal cell epithelioma-like changes overlying dermatofibroma.

Epidermis overlying dermatofibroma rarely displays basal cell epithelioma-like changes (BCE-like changes). Based on the histopathological findings, whether BCE-like changes are induced by dermal lesion or adnexal regression secondary to the solid fibrotic growth remains to be explored. From the standpoint of differentiation, we examined the BCE-like changes overlying dermatofibroma, normal epidermis, and hair follicles. PNA and two kinds of anti-keratin monoclonal antibodies were used to detect markers for epidermal differentiation. When PNA and anti-keratin monoclonal antibody (34betaB4) were used, no difference was observed in the staining patterns among BCE-like changes, hair follicles or normal basal cells. With the other anti-keratin antibody (34betaE12), BCE-like changes and normal basal cells were recognized, though the hair matrix was not. Thus the results obtained indicate that normal basal cells show the most similar differentiation to BCE-like changes.     

Sebaceous carcinoma in association with actinic keratosis: A report of two cases with an immunohistochemical study

We report two cases of sebaceous carcinoma associated with actinic keratosis (AK) with an immunohistochemical study, which suggests the possibility that sebaceous carcinoma really does develop within AK. Case 1 had sebaceous carcinoma arising within the atrophic type AK and case 2 had sebaceous carcinoma associated with bowenoid AK in the periphery and some parts of the overlying epidermis of the lesion.     

A Case of Superficial Epithelioma with Sebaceous Differentiation

Superficial epithelioma with sebaceous differentiation developed on the left cheek of a 58-year-old man over a three-year period. Biopsy of the lesion demonstrated plate-like lobules of basophilic basaloid cells with broad attachments to the overlying epidermis. Clusters of or solitary sebaceous cells were present within the lobules. Three tumor types were considered; a subtype of sebaceoma growing in the epidermis, an acanthotic seborrheic keratosis subtype with sebaceous differentiation, or a tumor of the follicular infundibulum with sebaceous differentiation.     

Superficial epithelioma with sebaceous differentiation

Five cases of superficial epithelioma with sebaceous differentiation (SESD) are reported. They occurred as solitary papules on the face of 5 patients, aged 57 to 72. The tumor is characterized by a superficial platelike proliferation of basaloid to squamoid cells with broad attachments to the overlying epidermis. Clusters of mature sebaceous cells are present within the tumors. None of the tumors have recurred or spread following simple excision. SESD is a non-aggressive tumor of uncertain histogenesis with a tendency toward sebaceous differentiation.     

Congenital multiple clustered dermatofibroma

Multiple clustered dermatofibroma (MCD) is a rare tumour which usually appears during the first and second decades of life. We report a man in whom the MCD was congenital, although during the first few years of his second decade it extended to involve a broad zone on the left hip, gluteal region and upper thigh.     

Subcutaneous Dermatofibroma

Dermatofibroma (DF) is usually confined to the dermis and the overlying epidermis is usually hyperplastic. Although DF with deep subcutaneous extension is commonly encountered, purely subcutaneous DF is uncommon. In this review, we describe a case of a 41-year-old male patient who presented with a painless, subcutaneous, hard papule on the left thigh. After the skin had been incised the lesion was totally removed, and histopathology revealed a subcutaneous dermatofibroma.