Microscopic inflammatory foci in burn scars: data from a porcine burn model

Background: Hypertrophic scars in burn victims usually occur after delayed wound healing and the active phase of scar formation can persist substantially even after wound closure. Currently, the pathophysiology of the hypertrophic scar is not completely understood. This study investigated the inflammatory response in scar tissue at week 6 post‐burn injury. Methods: A porcine deep dermal partial thickness burn model was used. At week 6 post‐burn, a total of 528 scar biopsies from 72 burn scars (7–8 biopsies from each scar) and 174 normal skin biopsies from 18 pigs were collected and examined histologically. Results: Microscopic inflammatory foci were identified in 17% (89/528) of scar biopsies. These microscopic inflammatory foci do not contain any irritant materials, are composed largely of polymorphonuclear cells with other inflammatory cells including multinucleate giant cells and show acute on chronic inflammatory response that has not been described previously in burn scars. Importantly, they are present in a significantly lower number in burns surgically debrided than in burns which have not been debrided. Conclusions: This study identifies microscopic inflammatory foci in the porcine scar tissue layer and recommends thorough cleaning/debriding of burned necrotic tissue in order to minimize the formation of these inflammatory foci in scar tissue. Wang X‐Q, Phillips GE, Wilkie I, Greer R, Kimble RM. Microscopic inflammatory foci in burn scars: data from a porcine burn model.     

Blisters over burn scars in a child

We present the case of an 11-month-old baby with a burn that healed normally over a month, but subsequently developed successive crops of blisters over the scar. There were no changes in his general condition. Clinical, immunological, histological and ultrastructural studies provided a diagnosis of mechanical dermatitis produced by microtrauma. Electron microscopy studies revealed the sub-epidermal nature of the blisters and the presence of underlying fibrin deposits.     

Exuberant verrucous carcinoma arising from a burn scar

Verrucous carcinoma (VC) is an unusual, well-differentiated, and low-grade type of squamous cell carcinoma, characterized by slow growth, low metastatic spread, local invasion, and little dysplasia. It occurs predominantly on the genitals, in the oropharynx, or in the palmoplantar region, being less frequent at other sites; however, it can occur on any part of the body. Many factors have been associated with its pathogenesis, including the presence of previous skin lesions, such as varicose, decubitus, traumatic, or neuropathic plantar ulcers. VC arising from a burn scar is rare. We report the case of a patient who developed exuberant VC on his knee many years after having burn injuries at that site.     

Malignant fibrous histiocytoma developing in a burn scar

A case of malignant fibrous histiocytoma (MFH) developing in a burn scar is presented. The patient was burnt at 3 years of age and 25 years later, a rapidly growing tumour developed in the burn scar. MFH was diagnosed by light and electron microscopy and by an immunoperoxidase method. This complication of a burn scar has not been previously reported.     

Eccrine syringofibroadenoma in a patient with a burn scar ulcer

A 72-year-old woman with a burn scar on the calves of both legs developed an ulcer on her right heel, surrounded by multiple verrucous nodules and plaques. She had experienced similar verrucous lesions on both legs in the burn scar areas. Although the clinical diagnosis was Marjolin's ulcer, histologically the ulcer region showed thick fibrous tissue without any atypical epithelial cells. The verrucous lesions were consistent with the diagnosis of eccrine syringofibroadenoma (ESFA). Moreover, an ESFA-like growth pattern was seen in the elevated margin of the ulcer. Our findings suggest that these lesions developed as a result of reactive eccrine duct hyperplasia followed by skin tissue remodelling.     

Neurotropic malignant melanoma occurring in a stable burn scar

Malignant melanoma occurring in burn scars is extremely rare. Nine cases are reported in the literature. We report a case of a small malignant melanoma arising in a stable thermal burn scar after a long latent period of 58 years. The case was unique in that it was of the de novo neurotropic variant. Fascicles of amelanotic, S100 protein-positive atypical spindle cells with neuroid appearance infiltrated deeply in the scarred dermis and perineural spaces. The pigmentation of the lesion was due to solar lentigo instead of atypical melanocytic proliferation in the overlying epidermis.     

Poxvirus‐induced angiogenesis after a thermal burn

Orf (contagious ecthyma) is a zoonotic infection caused by a dermatotropic parapoxvirus that commonly infects sheep, goats, and oxen. Parapoxviruses are transmitted to humans through contact with an infected animal or fomites. Orf virus infections can induce ulceration, and papulonodular, pustular, or ecthymic lesions of the skin after contact with an infected animal or contaminated fomite. Rarely, orf virus provokes extensive vasculo‐endothelial proliferation as a skin manifestation. Here, we present the case of an 8‐year old female with poxvirus‐induced vascular angiogenesis that developed 10 days after a thermal burn. An 8‐year‐old female presented at our outpatient clinic with red swellings and a yellow‐brown crust on them. After a thermal burn with hot water, she went to a clinic and the burn was dressed with nitrofurazone and covered for 2 days. When the dressing was removed after 2 days, nodules were seen in the burnt areas. When the clinical findings were considered with the histopathological features, a reactive vascular proliferation due to a viral agent was suspected. Following PCR, parapoxvirus ovis was detected. Viral infections such as pox virus can trigger pyogenic granulomas or pyogenic granuloma‐like vascular angiogenesis. Infectious agents must be considered when dealing with pyogenic granuloma‐like lesions.     

Pigmented basal cell carcinoma simulating melanoma in a burn scar

Pigmented basal cell carcinoma (BCC) can masquerade as malignant melanoma, especially in dark-skinned patients. We present a rare case of pigmented BCC located in an old burn scar in a 74-year-old Hispanic woman, and we demonstrate the potential value of dermatoscopy as a diagnostic tool in cases of pigmented lesions. Although clinically simulating melanoma, findings from the dermatoscopic examination of the lesion revealed characteristics of pigmented BCC, which was confirmed by histologic analysis of the biopsy specimen.