Dermatomyofibroma: case report and review

[Anatomoclinical and immunohistochemical study of 8 cases of dermatomyofibroma]

INTRODUCTION

Dermatomyofibroma (DMF) is a rare, benign tumour that is little-known among clinicians. However, it has typical clinical, histological and immunohistochemical features that distinguish it from other fibrous tumours.

METHOD

We report herein on the clinical, histological and immunohistochemical aspects of eight cases of DMF identified between 2008 and 2019 at the dermatopathology laboratory of Strasbourg.

RESULTS

Five men and three women of average age at diagnosis of 21 years and 9 months (range: 9 to 54 years) were included. Lesions ranged in size from 1 to 11cm. Most cases involved the upper body (6 cases), with one case on the abdomen and one on the side. The lesions presented as a solitary asymptomatic red or reddish brown nodule or plaque that gradually developed. The plaques were hard and caused functional discomfort on movement of the neck. Well-circumscribed spindle cell proliferation was noted in the reticular dermis parallel to the epidermis, without mitotic figures or cytological atypia. The subcutis was infiltrated in 5 cases. Expression of calponin was positive in all cases but one, while that of caldesmon, PS100 and desmin was negative. Expression of smooth muscle actin was positive in 2 cases, and both cases were also positive for stromylesin-3. CD34 was positive in 2 cases.

DISCUSSION

DMF is an extensive tumour capable of attaining large diameters and must be completely excised. The main differential diagnoses of DMF are dermatofibrosarcoma protuberans, dermatofibroma, fibrous hamartoma, myofibromatosis and cheloid. It can be identified based on various factors, whether clinical (young age, extensive lesion), histological (horizontal proliferation in the reticular dermis) or immunohistochemical (positive expression of calponin).

Plaque-like Myofibroblastic Tumor: 2 Cases of This Unusual Dermal Tumor Which Occurs in Infancy and Early Childhood

Plaque-like myofibroblastic tumor (PLMT) is a rare dermal spindle cell tumor which occurs in infancy or childhood within the first 4 years of life. The tumor is often pruritic and mostly presents on the lower back. We describe 2 cases with characteristic clinical and histological features of this entity, thus adding to the 10 cases which have so far been reported. Histologically, the lesion resembles a dermatofibroma. However, diffuse and uniform immunohistochemical staining with smooth muscle actin favors a myofibroblastic lineage. PLMT should be considered in the differential diagnosis of a dermal spindle cell tumor in the pediatric age-group.

Dermatomyofibromas Arising in Children: Report of Two New Cases and Review of the Literature

Dermatomyofibroma is a rare, benign mesenchymal proliferation not commonly reported in children. Two patients with biopsy-proven dermatomyofibroma were identified (one female, one male) at our institution, both with rather atypical clinical presentations. The clinical and histopathologic findings and a review of the literature are presented here. Features of dermatomyofibroma should be recognized and differentiated from those of similar-appearing entities since the prognosis of this benign tumor is favorable after complete excision.

Dermatomyofibroma

We report a case of dermatomyofibroma that, to our knowledge, is the second case reported in Brazil. About 100 cases have been reported worldwide. Dermatomyofibroma represents a rare, benign mesenchymal neoplasm of fibroblastic/myofibroblastic differentiation, with prolonged evolution and little or no symptoms. It most commonly occurs in young women and male children. Dermatomyofibroma can be easily confused with other clinical entities, which could lead to unnecessary treatments. Therefore, it is important that dermatologists and pediatricians suspect and start to consider this hypothesis in their diagnostic exercises.

Dermatomyofibromas presenting in pediatric patients: clinicopathologic characteristics and differential diagnosis

Dermatomyofibroma represents a rare benign fibroblastic/ myofibroblastic cutaneous tumor that mostly occurs in young adult women. It has been seldom reported in pediatric patients. In this analysis, the clinical, histopathological and immunohistochemical findings of 12 dermatomyofibromas occurring in patients up to 16 years of age are compared with those reported in adults. Six patients were male and six were female. Nine lesions were located on the neck, two on the back and one involved the chest. The usual presentation was as an asymptomatic plaque composed of bland spindled cells arranged in dermal fascicles that were oriented parallel to the epidermis. Immunohistochemically, the lesional cells expressed calponin in 11 cases, smooth muscle actin in six and muscle-specific actin in three. In contrast to prior reports from adults, dermatomyofibromas in pediatric patients do not show a female predilection. In addition, they are mostly located on the neck (56%), while in adults the most frequent location is the shoulder (35%). Dermatomyofibromas seem to stabilize after an initial period of enlargement. Punch biopsy and clinical follow up could be an alternative approach to the surgical excision in some cases of dermatomyofibroma, particularly in instances in which surgery might inflict cosmetic defects.

Development of dermatomyofibroma in a male infant

Dermatomyofibroma is a rare benign cutaneous mesenchymal neoplasm of the fibroblasts and myofibroblasts. The majority of dermatomyofibromas present as red-brown discolored plaques or nodules, commonly located on the shoulder, upper arm, axilla, neck, and/or upper trunk. These lesions develop most frequently in young female patients at a mean of 28-years-of-age. Herein, a case of dermatomyofibroma is reported that developed in an infant. A 4-month-old boy presented with an ill-defined bluish firm plaque on the trunk that developed 1 month after birth. Histopathologically, there was proliferation of bland-looking spindle cells with fascicular arrangement in the dermis and subcutaneous tissue. Immunohistochemistry showed that most of the tumor cells expressed diffuse positivity for vimentin and smooth muscle actin, but were negative for S-100 protein, desmin, and CD34.

Dermatomyofibroma: a case report of a rare disease

Dermato myofibroma is included in the group of benign cutaneous mesenchymal neoplastic lesions of fibroblastic and myofibroblastic lineage. It's a rare disease and there are approximately only one hundred cases described worldwide in the medical literature up to now. The present study reports the case of a young woman with typical clinical cutaneous lesion and histopathological diagnosis of dermato myofibroma. Special stains were carried out which showed preserved collagen fibers and immunohistochemistry was positive for vimentin and negative for actin and S100. As it is a rare disease, the histopathological findings are of great importance but clinical suspicion is possible in typical cases such as this one.

A unique case of multiple dermatomyofibromas

We report on a case of multiple dermatomyofibromas on the posterior neck of a 10-year-old boy. Dermatomyofibroma is a benign proliferation of myofibroblasts of the skin. It is more common in adolescents and young adults, with a female preponderance. It usually appears as a single plaque or nodule. To our knowledge, this is the first case of multiple dermatomyofibromas reported in the literature.

Plaque-like myofibroblastic tumor of infancy

Fibrohistiocytic neoplasms are relatively uncommon in infancy and childhood. We report an unusual spindle cell tumor occurring in two infants within the first 3 months of life. These tumors histologically resembled dermatofibromas, but the young age of onset, large size, and plaque-like morphology were distinctly different from those of dermatofibromas. The features of these neoplasms are discussed and the differential of other spindle cell tumors of infancy is reviewed.

Haemorrhagic dermatomyofibroma (plaque-like dermal fibromatosis): clinicopathological and immunohistochemical analysis of three cases resembling plaque-stage Kaposi's sarcoma

AIMS

Dermatomyofibroma (plaque-like dermal fibromatosis) represents a distinct clinicopathological entity in the spectrum of cutaneous mesenchymal neoplasms showing a myofibroblastic line of differentiation. These benign neoplasms occur frequently, but not exclusively, in young women, and the shoulder girdle as well as the upper trunk are common locations. Histologically, dermatomyofibroma is characterized by a plaque-like proliferation of cytologically bland spindle-shaped tumour cells containing an ill-defined, pale eosinophilic cytoplasm and elongated, neuroid nuclei. Neoplastic cells are arranged in bundles and fascicles orientated parallel to the skin surface, adnexal structures are spared and elastic fibres are increased and fragmented. Immunohistochemically, tumour cells express vimentin and variably muscle actin and alpha-smooth muscle actin, but are negative for desmin, CD34, S100, and epithelial markers. The main differential diagnosis includes hypertrophic scar, dermatofibroma (fibrous histiocytoma), pilar leiomyoma, neurofibroma, adult myofibromatosis, extra-abdominal fibromatosis and plaque-stage dermatofibrosarcoma protuberans.

METHODS AND RESULTS

We report three cases of dermatofibroma arising in male patients aged 31, 36, and 47 years on the thigh, chest wall and back, respectively. All lesions were completely excised and no local recurrence has been reported. Histologically, the neoplasms showed classical features of dermatomyofibroma; however, in addition abundant extravasated erythrocytes, scattered inflammatory cells, numerous capillaries, and sieve- and slit-like spaces, features resembling plaque-stage Kaposi's sarcoma, were noted. In none of the cases did spindled tumour cells stain positively for CD34, and HHV8 was not detected by polymerase chain reaction.

CONCLUSIONS

The reported cases widen the clinicopathological spectrum of dermatomyofibroma and emphasize plaque-stage Kaposi's sarcoma as an additional differential diagnosis.

Cutaneous smooth muscle neoplasms: clinical features, histologic findings, and treatment options

Cutaneous smooth muscle is present in 3 separate locations: arrector pili muscles, blood vessel walls, and genital/areolar skin. Benign or malignant smooth muscle neoplasms may arise from each of these locations. This review discusses the pathogenesis, clinical manifestations, histologic findings, prognosis, treatment options, and controversial areas of cutaneous smooth muscle neoplasms. ( J Am Acad Dermatol 2002;46:477-90.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be able to discuss the pathogenesis, clinical manifestations, histologic findings, prognosis, and treatment options of cutaneous smooth muscle neoplasms.

Dermatomyofibroma: a report of two cases, one occurring in a child

Dermatomyofibroma is a recently described plaque-like dermal tumour composed of myofibroblasts that usually presents around the shoulder, axilla and posterior neck, often in young adult females. Here, we present two cases, one from the posterior axilla of a 33-year-old female and one from the posterior neck of a 7-year-old male. Both were clinically red-brown lesions with histological and immunohistochemical features diagnostic of dermatomyofibroma. There was no evidence of aggressive biologic behaviour with 3 months and 2 months follow up, respectively. While the majority of dermatomyofibromas present in postpubescent females, the 7-year-old male exemplifies a subgroup occurring in male children which appears to show a particular predilection for the posterior neck.