Squamous cell carcinoma mimicking postburn granuloma of the forearm: a case report

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Arch Hand Microsurg. 2025;30(4):228-231

Publication date (electronic) : 2025 November 28

doi : https://doi.org/10.12790/ahm.25.0028

Nae-Ho Lee^1,2, Beom Jin Lim^1,2, Jin Yong Shin^1,2, Yoon Kyu Chung^1,2, Ho Sung Park^2,3, Si-Gyun Roh^,1,2

¹Department of Plastic and Reconstructive Surgery, Jeonbuk National University Hospital, Jeonju, Korea

²Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea

³Department of Pathology, Jeonbuk National University Hospital, Jeonju, Korea

Corresponding author: Si-Gyun Roh Department of Plastic and Reconstructive Surgery, Jeonbuk National University Hospital, 20 Geonji-ro, Deokjin-gu, Jeonju 54907, Korea Tel: +82-63-250-1865 Fax: +82-63-250-1866 E-mail: pssroh@jbnu.ac.kr

Received 2025 August 13; Revised 2025 October 14; Accepted 2025 October 23.

Abstract

Introduction

Burn injuries can lead to a broad spectrum of cutaneous sequelae, including dyspigmentation, erythema, hypertrophic scars, keloids, contractures, and scar instability, most of which are benign. Malignant transformation is uncommon and is classically represented by Marjolin’s ulcer, which refers to malignant degeneration of a chronic wound or scar, most commonly resulting in squamous cell carcinoma (SCC), although other histologic types such as basal cell carcinoma or melanoma may also occur [1,2].

Due to this long latency period, nodular lesions developing shortly after a burn injury are often presumed to be benign. However, overlooking the possibility of malignancy may lead to delayed diagnosis or incomplete excision.

Here, we present a case of SCC arising only one month after a thermal burn, initially misdiagnosed as a postburn granuloma. Previous literature has defined malignant transformation occurring within 12 months of the initial injury as the acute type of Marjolin’s ulcer or acute burn scar carcinoma, in contrast to the more common chronic type developing years later [3]. Although a single case cannot establish definitive guidelines, this report draws attention to a significant diagnostic pitfall and suggests that histopathologic evaluation should be considered for suspicious burn-related nodular lesions, even during the acute or subacute phase.

Written informed consent was obtained for publication of this case report and accompanying images.

Case report

A 73-year-old woman presented with a firm, erythematous nodule on the dorsal aspect of her left forearm. She sustained a thermal burn in July 2023, after accidental contact with a hot frying pan, and presented to our outpatient clinic on August 21, 2023, approximately 4 weeks after the injury without any medical treatment. Her past medical history included hypertension and osteoporosis, both well controlled with medication. She had no history of immunosuppressive therapy, autoimmune disease, or previous cutaneous malignancy. The bullae resulting from the burn ruptured and healed spontaneously.

On physical examination, a 1.0×1.0 cm nodular lesion with surrounding erythema was observed at the site of the previous burn (Fig. 1). No ulceration, induration, or palpable lymphadenopathy was noted. Given the recent burn history and benign-appearing nature of the lesion, a postburn granuloma was suspected.

Fig. 1.

Clinical photograph demonstrating an erythematous nodule with a central crust on the dorsal aspect of the left forearm at the site of a recent burn.

The lesion was excised under local anesthesia using an elliptical incision design to optimize linear wound closure and minimize dog-ear deformity. Because malignancy was not suspected at the time, no oncologic safety margin was formally planned. The wound was closed primarily without tension (Fig. 2A, 2B).

Fig. 2.

(A) Preoperative view showing the planned elliptical incision around the nodule on the dorsal left forearm, designed to facilitate linear closure and minimize dog-ear deformity. (B) Immediate postoperative view following primary closure without tension.

Histopathologic examination unexpectedly revealed well-differentiated SCC characterized by hyperkeratosis, acanthosis, and nests of atypical keratinocytes infiltrating the dermis (Fig. 3A). High-power views demonstrated tumor cell nests with keratin plugs and small infiltrating nests within the dermis (Fig. 3B). Immunohistochemistry was performed to assist in the differential diagnosis from other cutaneous adnexal tumors, revealing diffuse cytokeratin (AE1/AE3) positivity, focal strong nuclear p53 expression, and a low Ki-67 proliferation index, supporting squamous cell differentiation with limited proliferative activity. Although the excision was not intended for oncologic purposes, the elliptical design for linear closure inadvertently provided adequate margins. Histopathologic evaluation confirmed that all surgical margins were free of tumor involvement, with the closest margin estimated at approximately 2 to 3 mm. Although this margin was narrower than the recommended 4 to 6 mm for low-risk cutaneous SCC, histologic clearance was achieved. Given the patient’s advanced age, re-excision was deferred, and closer observation was chosen.

Fig. 3.

(A) Low-power view reveals hyperkeratosis, acanthosis, and infiltrative growth (arrows) of epidermal squamous cells into the dermis (H&E stain, ×40). (B) High-power view of the dot-lined square in (A) shows a tumor cell nest with a keratin plug (upper left) and small infiltrating nests (arrows) (H&E stain, ×200).

Following the unexpected diagnosis, the patient underwent a comprehensive staging work-up, including chest computed tomography, whole-body bone scan scintigraphy, and positron emission tomography-computed tomography. All studies were negative for distant metastasis or regional lymph node involvement. The imaging work-up was performed in accordance with the NCCN (National Comprehensive Cancer Network) guidelines for cutaneous SCC, which recommend systemic evaluation in histologically confirmed or clinically high-risk lesions. At 6 months of follow-up, there has been no evidence of recurrence or regional/distant metastasis (Fig. 4).

Fig. 4.

Postoperative view at the 6-month follow-up, displaying a well-healed linear scar on the dorsal left forearm without evidence of recurrence. The patient was later lost to follow-up after 6 months.

Discussion

Burn injuries can result in a diverse array of cutaneous sequelae. Benign conditions such as granulation tissue, hypertrophic scars, and granulomas are common, while malignant transformation is rare. Malignant transformation has been reported to occur in approximately 0.77% to 2% of chronic burn scars. Among these, the acute type—defined as occurring within 12 months of injury—accounts for fewer than 2% of all Marjolin’s ulcers, highlighting the extreme rarity of such cases [1,2,4].

In contrast, the acute or subacute development of SCC at a burn site, as seen in our case, is exceptionally uncommon. Only a small number of similar cases have been reported [3,4]. This rarity increases the likelihood that clinicians will assume a benign etiology when encountering a nodular lesion in a recently burned area.

In this case, the erythematous, nodular appearance strongly suggested a postburn granuloma, a benign lesion. Such lesions are frequently excised without prior biopsy, and histologic examination may be omitted when benignity is strongly suspected. However, this approach carries the risk of incomplete excision or delayed diagnosis if the lesion is malignant.

Histopathologic confirmation should be strongly considered for any suspicious lesion arising at a burn site, regardless of the interval since injury. Features such as rapid growth, persistent ulceration, or induration should heighten suspicion for malignancy [5]. Early biopsy is especially important in functionally and cosmetically sensitive areas where achieving adequate margins may be challenging.

The forearm and hand are anatomically significant regions where wide excision can lead to substantial functional impairment. Delayed diagnosis of SCC in these areas may necessitate extensive resection and complex reconstruction. Prompt identification of malignancy can therefore enable more conservative surgical management and better preservation of function [6].

When a nodular lesion develops after a burn injury, the differential diagnosis includes hypertrophic scars, pyogenic granulomas, epidermal inclusion cysts, and benign granulomatous lesions, as well as malignant entities such as SCC, and rarely, melanoma or basal cell carcinoma. Maintaining a high index of suspicion is crucial, and malignancy should always be considered, especially for atypical or rapidly progressing lesions [1,2].

Management of SCC at burn sites should adhere to standard oncologic principles. Wide excision with clear margins is the treatment of choice, and regional lymph node assessment should be considered for high-risk lesions. Careful follow-up is required to monitor for recurrence or metastasis [7]. At the time of submission, 6 months was the latest available follow-up, during which the patient showed no evidence of recurrence or metastasis. Although she was advised to continue regular surveillance, she was subsequently lost to follow-up due to relocation. Nevertheless, there had been no clinical signs of recurrence at the last contact.

In conclusion, nodular lesions arising at burn sites—even during the acute or subacute phase—should not be presumed benign. This case underscores the importance of early histopathologic confirmation of suspicious lesions, which can prevent diagnostic errors, ensure appropriate treatment, and preserve function, especially in anatomically sensitive regions.

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