A 16-Year-Old Girl with Sinonasal-Cutaneous Fistula Following Excision and Radiotherapy for Rhabdomyosarcoma Requiring Reconstructive Surgery Using an Expanded Forehead Flap

Introduction

Rhabdomyosarcoma (RMS) is a rare mesenchymal tumor that affects children and adolescents, with an annual incidence of 4.3 cases per 1 million [1]. Among the head and neck rhabdomyosarcomas (HNRMS), sinonasal RMS accounts for only 10.7% [2]. There are 4 subtypes: embryonal, alveolar, anaplastic, and mixed-type RMS [2]. Sinonasal RMS is aggressive and locally invasive [3]. The general treatments for RMS include surgical resection followed by chemotherapy and radiotherapy [4].

While radiation can provide benefits for cancer, it can also damage normal tissues and cause complications [5]. There have been several reports suggesting that radiation can lead to ulceration, fistula formation in the skin, and even osteoradionecrosis [6–8].

As radiation ulcers are associated with ischemia, infection, and low viability, surgical excision of affected tissue and covering with well-vascularized tissue is recommended [9]. For facial defects, the forehead flap is a good choice because of its matching color and texture [10], and expansion technique provides additional donor skin surface [11]. The expanded forehead flap is a safe procedure for nasal reconstruction [12]. The double forehead flap has been used to reconstruct the nasal lining and skin [13]. A bipaddle chimeric forehead flap composed of skin and periosteum can be used to reconstruct nasal full-thickness defects [14]. However, due to the low incidence and limited cases of RMS in adolescents, there is little information available on reconstruction of ulcerative defects due to sinonasal RMS treated by radiotherapy.

This report presents the case of a 16-year-old girl with a sinonasal-cutaneous fistula following excision and radiotherapy for rhabdomyosarcoma, which required reconstructive surgery using an expanded forehead flap.

Case Report

A 16-year-old girl presented to our clinic (Shanghai) with sinonasal-cutaneous fistula. Prior to her presentation at our department, she presented with bilateral intermittent nasal congestion, without headache or purulent discharge, 3 years ago.

The patient was referred to a local hospital (Henan province) where orbital computed tomography (CT) revealed a bilateral lesion occupying the anterior septal sinus, frontal sinus, and left lateral superior orbital rim. A subsequent nasal endoscopic biopsy revealed a neoplasm in the nasal cavity, and the pathology biopsy revealed an embryonal rhabdomyosarcoma (ERMS).

One month later, the patient underwent skull base tumor resection, nasal cavity and sinus tumor resection, and low-temperature plasma ablation at a local hospital (Henan province). Two weeks after the operation, she received intensity-modulated radiation therapy (IMRT) for 5 weeks, 5 times per week, and 2Gy each time, for a total of 50 Gy. Chemotherapy started 2 weeks after radiotherapy, using a vincristine, dactinomycin, and cyclophosphamide (VAC) regimen of 3.5 mg vindesine, 0.5 mg actinomycin, and 600 mg cyclophosphamide. The course of treatment was 9 months. During the chemotherapy, there was leukopenia and MRSA was detected on the nasal test strip. Antibiotic therapy (linezolid) was used and the infection was controlled.

About 1 month later, an ulcer appeared at the nasal root. The lesion gradually expanded, until the skin defect at the nasal root was connected to the nasal cavity. She was referred to our hospital due to the defect. Physical examination revealed local sinonasal-cutaneous fistula, with 2 oval-shaped defects measuring approximately 1×0.6 cm and 0.8×0.4 cm, respectively. There is a small amount of mucosal secretion. The shape of the nasal tip and wing was basically normal, with absence of smell.

To obtain sufficient skin tissue to repair the defect, we first expanded the skin in the forehead using a tissue expander for 7 months (Figure 1A). The CT scan in our hospital showed bone interruptions and partial soft tissue defects in the cranial, orbital, nasal, and maxillofacial regions (Figure 2A). The shadow of the tissue expander was seen subcutaneously on the forehead (Figure 2B). Then, we trimmed the skin around the defects to remove the necrotic tissue (Figure 1B). A defect with a width of 2.1 cm was formed (Figure 1C). Subsequently, the forehead flap was separated in the middle, and half was transferred (epidermal surface inward) to repair the lining, while the other half of the flap was transferred to reconstruct the external defect. Simultaneously, the prosthesis was inserted between the 2 flaps (Figure 1D). Two weeks later, a fistula was formed at the left border between the flap and local tissue (Figure 1E). Then, the pedicle of the flap was divided from the forehead and inserted into the upper border of the defect (Figure 1F). The skin tissue around the defect was sent for histological examination. Hematoxylin-eosin (H&E) staining of the tissue surrounded the defect showed normal skin tissue structure, but there was inflammatory cell infiltration in the superficial dermis and around the small blood vessels (Figure 3A). Ultimately, the sinonasal-cutaneous fistula was closed (Figure 1G). One year after surgery, there was no recurrence of the ulcer (Figure 1H). Nasal endoscopic results showed that the internal flap had survived well (Figure 3B, 3C).

Discussion

Sinonasal rhabdomyosarcoma (RMS) is a rare and aggressive disease in children and adolescents. Cutaneous fistula following surgical excision and radiotherapy for RMS can be treated with a surgical flap.

Radiotherapy is a cornerstone of the multimodality treatment of pediatric rhabdomyosarcoma and contributes to improved patient outcomes [15]. However, radiation-induced refractory ulcers often require reconstructive surgery [16].

Traditionally, small-to-medium-sized defects usually require local flaps [17], while the forehead flap can be used to treat large nasal defects [18]. Besides the size of the nasal defect area, the thickness of involved tissue also affects the choice of surgical methods. For full-thickness nasal defects, a bipaddle chimeric forehead flap [14] composed of skin and periosteum has been reported to simultaneously reconstruct nasal full-thickness defects. However, this method has limitations.

Firstly, it is suitable for elderly people with loose skin. Our patient was an adolescent with tight skin; thus, the use of a tissue expander was necessary. Secondly, the supratrochlear artery primarily supplies the skin rather than the periosteum [19], meaning that the periosteum, with less blood supply, is not suitable for repairing the nasal lining affected by irradiation. The reconstructed nasal lining through the periosteal flap still requires a longer time for mucosalization, which further increases the risk of infection; whereas the epithelial structure of the skin is more similar to that of the nasal lining [20]. Here, we used an expanded forehead flap with abundant blood supply to simultaneously reconstruct the external skin and nasal lining of the nasal fistula, which is suitable for tissue defects caused by radiation.

Previously, a forehead flap has been used to reconstruct composite nasal defects [10,11]. Both studies used forehead flap to immediately reconstruct the defects caused by cancer or trauma, but no forehead flaps have been used for reconstruction of radiation-induced defects. The effects of radiation-induced skin ulcers are usually long-lasting [16]. It is reported that the interval between radiation and reconstructive surgery usually ranges from 3 months to 25 years, which means that the timing of the repair needs to be determined after evaluating the lesion [9]. Our patient underwent reconstruction 3 years after radiation therapy, which greatly improves the success rate of reconstruction.

A double forehead flap has been used to reconstruct both the nasal lining and the skin [13]. Compared with this double forehead flap, we cut the forehead flap down the middle to reconstruct the nasal lining and external skin at the same time, reducing scaring of the forehead.

This case also provides evidence of tissue changes induced by radiation. The graft obtained from the first surgery survived but showed local poor healing (Figure 1D). We speculated that this was due to the long-term effects of radiotherapy on the surrounding skin or the postoperative shrinkage of the expanded skin. This suggested that the tissue expander should be used for an extended period of time to stabilize the skin tissue. Hematoxylin-eosin (H&E) staining of the skin around the defect showed aggregated inflammatory cells. This phenomenon may be an effect of late radiation [21]. Therefore, reconstruction of radiation-induced tissue defects requires consideration of multiple factors, including the affected tissues, timing, and selection of the best reconstruction method.

Conclusions

RMS is a rare malignancy in children and adolescents. Tissue ulcers and fistulas can occur as complications following radio-therapy for RMS. This report highlights the challenges of post-radiation reconstructive surgery and describes how an expanded forehead flap can achieve an acceptable cosmetic outcome in a patient with a sinonasal-cutaneous fistula.