Wide Excision and Flap Reconstruction in Perineal Extramammary Paget’s Disease Patients

1. Introduction

Extramammary Paget’s disease (EMPD) is an uncommon but low-risk intraepidermal adenocarcinoma arising in apocrine gland bearing skin, most often involves the perianal and perineal region in both males and females [1,2,3]. Perineal EMPD typically affects elderly patients and is frequently diagnosed late with numbers up to 3 to 4 years, due to its nonspecific clinical features which is often mistaken as eczema, dermatitis, or tinea cruris [4,5].

Wide local excision with histologically negative margins remains the standard treatment for localized EMPD, but resection often leaves extensive superficial defects involving the penis, scrotum, perineum, and adjacent pubic skin [4,5,6,7]. Reconstruction after EMPD excision can be challenging due to the necessity to restore durable coverage, preserve elasticity for penile function and testicular thermoregulation, and maintain acceptable cosmetic contour in a psychologically sensitive area [8,9,10]. Various reconstructive options have been described for perineal defects, ranging from split thickness skin grafts and local advancement flaps for smaller, well-approximated defects, to musculocutaneous flaps for larger or deeper defects requiring vascularized bulk, and perforator-based flaps for thin, pliable coverage with reduced donor-site morbidity [11,12,13,14]. Thin skin grafts may be acceptable in selected settings; however, larger grafted areas can be limited by contracture, contour mismatch, and erectile dysfunction, whereas myocutaneous flaps due to its bulky nature can increase scrotal temperature and cause contour deformity [15,16].

The choice of flap of EMPD reconstruction depends on defect size, depth, location, and the need to balance durable coverage with preservation of perineal contour and function. The anterolateral thigh (ALT) perforator flap has been a versatile option for various reconstructive purposes and has been successfully applied in perineal reconstruction as a pedicled flap [17,18]. The pedicled ALT flap can provide reliable vascular supply and substantial tissue volume for large, deep, or contour demanding defects, including exposed testicles or pubic involvement, but it may be relatively bulky for fine perineal contour matching in some patients [19,20,21]. The tensor fascia lata (TFL) flap offers reliable, well-vascularized coverage for large groin or perineal defects and is particularly useful when stronger tissue coverage is needed, although its bulky nature and arc of rotation can be a limitation for superficial and medial perineal defects [11,22,23,24]. Perforator-based flaps, particularly internal pudendal artery perforator (IPAP) flaps, have become important options for large perineal defects because they provide thin, pliable, well-vascularized tissue while preserving the underlying muscle and reducing donor site morbidity [14,25]. The superficial circumflex iliac artery perforator (SCIP) flap is similarly attractive for penoscrotal reconstruction as it provides thin, pliable tissue close to the operative field, making it useful when contour preservation is a priority [9,26,27,28].

In this study, we selectively employed pedicled SCIP flaps for smaller defects requiring thin coverage and pedicled ALT flaps for larger or deeper defects requiring greater tissue volume following wide excision of perineal EMPD. This study aims to evaluate the safety and efficacy of pedicled flap reconstruction for perineal EMPD, comparing outcomes between SCIP and ALT flap groups whilst focusing on flap viability, complications, patient satisfaction, and oncologic outcomes.

2. Materials and Methods

This retrospective case study included male and female patients with perineal EMPD who underwent consecutive wide local excision and pedicled flap reconstruction using either SCIP or ALT flaps between January 2023 and December 2024. The inclusion criteria for this case series were: (1) histologically confirmed EMPD involving the perineal or genital region; (2) lesions involving the pubic region, penis, perineum, and/or scrotum requiring wide excision; and (3) reconstruction using a pedicled SCIP or ALT flap. Patients with distant metastasis, severe systemic disease precluding surgery, or incomplete medical records were excluded. Figure 1 entails the algorithm for perineal EMPD reconstruction.

2.1. Flap Selection Criteria

The choice between pedicled SCIP and pedicled ALT flap was determined by defect size, location, and tissue requirement. Pedicled SCIP flaps were preferred for defects requiring thin, pliable coverage of the penile shaft, scrotum, and adjacent pubic region where tissue bulk would compromise contour or thermoregulatory function [9,27,28]. Pedicled ALT flaps were selected for infected wound, or larger defects where greater tissue volume and arc of rotation were required to achieve tension-free closure, particularly for combined perineal and inguinal defects [12,19,21,29,30]. Lesion extent was documented, and defect size was estimated to guide reconstructive planning. Preoperative computed tomographic angiography was performed to map the superficial circumflex iliac artery and thigh perforators to identify suitable pedicles for flap elevation [31,32].

2.2. Surgical Technique

2.2.1. Lesion Excision

Under general anesthesia, patients positioned supine for anterior or lateral lesions and in lithotomy for perineal lesions, depending on lesion location [17,21,25]. The clinical margin of the lesion was outlined, extending 2-3 cm beyond the visible edge depending on edema and suspected subclinical spread. Excision depth extended to the deep fascial layer in the penile region, the outer fascial layer of the spermaticord in the scrotum, and the deep subcutaneous fat in the pubic and inguinal regions. After tumor removal, the wound was irrigated and hemostasis was achieved. Frozen-section biopsies were obtained from 6-7 sites along the lateral margins and the base of the lesion. When margins were positive, additional 2 cm re-excision was performed until all margins were negative.

2.2.2. Pedicled SCIP Flap Design and Elevation

For SCIP flap reconstruction, the superficial (medial) branch of the superficial circumflex iliac artery (SCIA) was identified preoperatively using multidetector computed tomographic angiography and confirmed intraoperatively with a handheld Doppler device [9,28]. The superficial branch was preferentially used to avoid injury to the lateral femoral cutaneous nerve and to simplify dissection The superficial branch was preferentially used to avoid injury to the lateral femoral cutaneous nerve and to simplify dissection [33,34]. The flap was designed over the groin region with dimensions approximately 2-3 cm larger than the defect, whilst maintaining the pedicle width of 2-3 cm. The pivot point was centered on the dominant perforator closest to the defect, and the pedicle length was confirmed to allow tension-free insetting [16,27,34]. The flap was elevated in the superficial fascial plane, superficial to the deep fascia and deep to the Scarpa’s fascia. The flap was then transposed as a pedicled flap through a subcutaneous tunnel or via an open incision to reach the perineal defect and inset without tension using layered closure. Suction drains were placed beneath the flap and at the donor site. The donor site was then primary closed for all cases.

2.2.3. Pedicled ALT Flap Design and Elevation

For ALT flap reconstruction, perforators arising from the descending branch of the lateral circumflex femoral artery were mapped preoperatively using computed tomographic angiography and confirmed intraoperatively with a handheld Doppler device [20,31]. The flap was designed over the anterolateral thigh with the perforator at its center, with dimensions tailored to the defect size. An exploratory incision along the medial border of the flap was first made to identify and confirm suitable perforators [18,19]. Once confirmed, the flap was the elevated in the subfascial plane and then dissected proximally along the pedicle to achieve an adequate arc of rotation for tension-free transfer to the perineal defect [21,25,29].

2.3. Postoperative Management and Follow-Up

Ambulation was limited for 3-5 days to minimize tension on the flap. Drains were removed when output decreased below 30 mL per day, and skin sutures were removed 10-14 days postoperatively. Patients were followed at 1 and 3 months, then every 3-6 months for at least 1 year and subsequently as clinically indicated. During outpatient follow-up, flap-related complications, including total flap loss, flap necrosis, contracture, functional impairment, donor-site healing problems, and systemic complications, were recorded. Oncologic outcomes were evaluated based on recurrence, distant metastasis, and tumor-related death. Patient reported satisfaction was also assessed based on overall cosmetic and functional outcomes.

2.4. Data Collection and Statistical Analysis

Collected variables for analysis included age, comorbidities prior to surgery, lesion location, defect size, flap type, flap dimensions, operative time, flap-related complications, recurrence, survival, and patient-reported satisfaction. Patient-reported satisfaction was graded using a four-point ordinal scale: 0 (not applicable due to mortality), 1 (poor), 2 (satisfactory), 3 (good), 4 (excellent). All statistical analysis was performed using IBM SPSS Statistics (ver 26.0). Normal continuous variables were expressed as means with standard deviation (SD) and range, whereas non-normal continuous variables were expressed as median with interquartile ranges (IQR) and range. Categorical variables were expressed as frequency with percentages.

3. Results

3.1. Patient Characteristics

In this case series, a total of 15 patients were included with a mean age of 63 years (SD 7.3, range 51-78) where majority were males (73.3%). The median duration of symptoms before diagnosis was 14 months (IQR 9-24, range 5-84). One patient (6.7%) had enlarged inguinal lymph nodes, with one of the nodes showed metastatic involvement on pathological examination. Further patient and flap characteristics are summarized in Table 1. After wide excision with frozen-section margin control, defect sizes ranged from 5 x 6 cm to 16 x 18 cm. The mean defect area was 72.6 cm² (SD 54, range 18-234). 10 patients underwent reconstruction using pedicled SCIP flaps (mean flap size 106 cm², SD 23.3, range 30-240), and 5 patients underwent reconstruction using pedicled ALT flaps (mean flap size 245.2 cm², SD 41.2, range 120-338). In the SCIP group, the superficial SCIA branch was utilized as the pedicle in all flaps. In the ALT group, perforators form the descending branch of the lateral circumflex femoral artery were used in all cases. Autologous full-thickness skin grafts were additionally used in one patient in the ALT group to cover residual defects not amendable to primary closure or flap coverage. Further operative details and flap characteristics are summarized in Table 2.

3.2. Flap Survival and Complications

All pedicled flaps survived without total flap loss. One patient (6.7%) in the SCIP group developed limited partial necrosis at the distal flap tip, representing approximately 2% of the total flap area. This area was successfully managed with debridement and local wound care without compromising final function or aesthetic outcomes. Among patients who received combined skin grafting, one (6.7%) experienced approximately 5% skin graft loss, which healed with conservative management. There were no cases of significant donor-site morbidity, or major complication such as severe scar contracture, or voiding dysfunction. No patients developed deep vein thrombosis or pulmonary embolism. Donor sites in the SCIP group were primarily closed in all cases. In the ALT group, split-thickness skin grafts were required for donor-site closure in one patient due to wider flap harvest. Further postoperative characteristics and outcomes are summarized in Table 3.

3.3. Oncologic Outcomes and Patient Satisfaction

All patients achieved negative margins on final histopathologic examination following frozen-section guided re-excision when necessary. During a mean follow-up of 17.7 months (SD 1.3, range 7-24), one patient (6.7%) developed distant metastasis and tumor-related death. The remaining 14 patients (93.3%) reported overall satisfaction with their postoperative appearance and functional capacity (median 4, IQR 3-4, range 0-4) (example cases, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6 and Figure 7).

On outpatient examination, the reconstructed perineal region demonstrated good tissue elasticity, minimal scarring, natural contour, and preserved urination comparable to preoperative status. The thin, pliable nature of the SCIP flap closely matched native perineal tissue in texture and contour, contributing to favorable aesthetic outcomes in the SCIP group. In the ALT group, no patient reported scrotal thermal discomfort or functional limitations during activities of daily living.

4. Discussion

Wide local excision for localized EMPD commonly leaves extensive superficial defects of the penis, scrotum, perineum, and adjacent pubic skin, and reconstruction must restore durable coverage while preserving elasticity, contour, and thermoregulatory function in a sensitive anatomic region [34]. This case series supports pedicled SCIP and ALT flaps as practical primary option as all flaps utilized survived, major complications were uncommon, and postoperative contour, elasticity, and urinary function were preserved with high patient satisfaction post-reconstruction. The selective use of thin pedicled SCIP flaps for smaller or more superficial defects and pedicled ALT flaps for larger defects requiring greater tissue volume allowed tailored reconstruction across a spectrum of defects sizes and location [28]. This case series supports that both ALT and SCIP flaps are well-suited for perineal reconstruction when applied according to appropriate selection criteria [18,27].

Compared with split-thickness skin grafting, which is most appropriate for smaller, well-approximated defects, flap reconstruction is better suited to broader post-EMPD defects that require vascularized tissue and more reliable contour restoration [35]. Compared with myocutaneous options, perforator-based flaps avoid the bulk that can increase scrotal temperature and create contour deformity [16]. Maguiña [36] reported that skin graft coverage of scrotal defects following Fournier gangrene was associated with contracture and functional impairment. This is in contrast to free tissue transfer, where pedicled flaps avoid microsurgical anastomosis and recipient vessel dissection, which shortens operative time and makes them a practical option for regional reconstruction [16,21,26,31]. This is particularly relevant in perineal EMPD, where preserving a natural outline and minimizing functional disturbance matter as much as closing the defect itself.

When compared with other established regional flaps, SCIP and ALT offer a favorable balance of reach, pliability, and donor-site preservation [21,30,33]. Aslim [13] reported successful reconstruction of large groin defects using pedicled ALT and vertical rectus abdominis musculocutaneous (VRAM) flaps in 23 patients, achieving satisfactory coverage with minimal morbidity. However, the VRAM flap carries risk of abdominal wall complications including abscesses, hernias, and fistulae as it can compromise abdominal wall integrity [11,17,23]. As such, VRAM remains a dependable option when an abdominal approach is already required, but the reconstructive choice should still be drive by the operative field and the need to minimize unnecessary donor-site burden. TFL can provide reliable coverage for large groin or perineal defects, but its bulk and arc of rotation can limit its use in superficial or medial perineal defects [23]. The pedicled SCIP and ALT flaps used in this case series avoided these morbidities while providing ample tissue for reconstruction. Multiple perforator flaps have also been advocated for large perineal defects. Sung [14] reported reconstruction of 14 patients with perineal defects greater than 100 cm² using multiple perforator flaps, primarily bilateral IPAP flaps, with 6 patients experiencing minor complications such as wound dehiscence and partial flap margin necrosis. While this approach provides thin, pliable, well-vascularized tissue while preserving muscle and reducing donor-site morbidity, it requires identification and dissection of multiple perforators, increasing operative complexity and time. However, SCIP flaps offers similar benefits as it places comparable tissue close to the operative field and is particularly useful when contour preservation is a priority [33].

4.1. Technical Considerations: SCIP Versus ALT Flap Selection (to Add More)

Technical selection between SCIP and ALT should be based on defect size, depth, and topography. SCIP is best suited to thin, pliable coverage of the penile shaft, scrotum, and adjacent pubic region, especially when tissue bulk would compromise contour or thermoregulation, and it can also be used as an ultrathin flap for very superficial perineal defects [33]. However, as SCIP flap provides a limited tissue volume, it makes it less suitable for large or deeply excavated defects. In this case series, all 10 SCIP flaps were utilized for defects of moderate size with satisfactory outcomes, consistent with previously reported applications [27,28].

Whereas the pedicled ALT flap provides a greater volume of tissue and a longer, more robust pedicle, allowing appropriate coverage of extensive defects that cannot be addressed by the SCIP flap alone [18,37]. The well-characterized vascular anatomy of the descending branch of the lateral circumflex femoral artery makes the ALT flap technically reliable, and its versatility in terms of flap dimensions enables reconstruction of a wide range of defect geometries [19,21,30,31]. However, the potential disadvantages for using ALT flaps include donor-site morbidity on the thigh and the need for intraoperative thinning to avoid excessive bulk in genital reconstruction [8].

As such, preoperative CTA and intraoperative Doppler mapping are useful for both flaps, and the operative algorithm in this series supports unilateral reconstruction for smaller defects and bilateral reconstruction when the defect is larger or more extensive [33].

4.2. Oncologic Safety

Oncologic safety was preserved in this cohort. Frozen-section guided re-excision achieved negative margins in all patients, and the oncologic outcome profile remained acceptable during follow-up, with one recurrence or metastatic event resulting in one tumor-related death. The observed local recurrence rate of 6.7% compares favorably with previously reported rates for perineal EMPD, which range from 8% to 61% depending on margin status and follow-up duration [5,6,38]. Importantly, reconstruction did not appear to compromise the ability to obtain margin-negative resection, and the low rate of major flap-related complications suggests that immediate reconstruction can be performed safely after adequate oncologic clearance.

4.3. Limitations and Future Direction

The main limitation of this study are its retrospective design, single-center setting, and small sample size of 15 patients, together with a median follow-up of 18 months, which may underestimate late recurrence and delayed functional problems, as EMPD is known for late relapse after many years post initial treatment. Furthermore, the non-randomized assignment of flap type precludes direct statistical comparison between the SCIP and ALT groups. Future studies should validate the selection algorithm in larger multicenter cohorts and compare SCIP and ALT directly with skin grafting, VRAM, TFL, IPAP reconstruction using standardized patient-reported cosmetic and functional outcomes, along with longer oncologic surveillance.

5. Conclusions

Pedicled SCIP and ALT flap reconstruction after wide excision of perineal EMPD provides reliable, well-vascularized tissue coverage with high flap survival, low complication rates, and excellent cosmetic and functional outcomes. Pedicled SCIP flaps are ideally suited for defects requiring thin, pliable coverage with minimal donor-site morbidity, while pedicled ALT flaps offer greater tissue volume for larger or more complex defects. When necessary, combination with bilateral pedicled scrotal flaps and selective skin grafting allows tailored reconstruction of extensive, three-dimensional defects while maintaining oncologic safety through frozen-section-guided margin control. A flap selection strategy based on defect size, location, and tissue requirements enable optimized outcomes across the full spectrum of perineal EMPD defects.