Pilonidal Disease → SCC: When to Biopsy & How to Act | Medipyxis
Squamous Cell Carcinoma Arising from Pilonidal Disease: How to Recognize Malignant Wound Transformation (Case Report + Clinician Guide)
Clinical takeaway: When a pilonidal wound stalls or evolves—biopsy early. Delays can allow malignant change (Marjolin ulcer) to progress and complicate care. [3, 5]
Why this matters
(SCC) developing in long‑standing pilonidal disease is rare (~0.1%) but potentially devastating. It can masquerade as a “routine” nonhealing sinus, leading to missed or delayed diagnoses. A recent case report from NYU Grossman School of Medicine underscores the point and offers practical lessons for wound and surgical teams. [1]
Case in brief
Patient: 38‑year‑old woman with a longstanding mass of the left upper buttock and a history of pilonidal disease.
Course before diagnosis: Four months of continuous drainage from a ruptured mass; referral to surgery was missed due to scheduling barriers. She re‑presented months later; exam at a wound center revealed a vertically aligned, fissure‑like, full‑thickness wound 3–4 cm deep with irregular, frond‑like edges that bled easily and possible sacral bone involvement. The team began local care (packing with dilute sodium hypochlorite and a foam cover) and performed a biopsy. [5, 7, 8]
Diagnosis & plan: Pathology returned SCC infiltrating the reticular dermis. The patient was referred to surgical oncology for complete excision. Given the wound depth and concern for expansive local disease/regional spread, neoadjuvant therapy was considered to downsize the lesion and avoid highly morbid surgery. [3]
System lens: There was a five‑month gap between the initial presentation and the wound‑care visit; in that interval she twice visited the ED without a tissue diagnosis, and the wound length increased from ~3 cm to ~6 cm. [2, 4]
Marjolin ulcer: the historical pattern you can still spot at the bedside
The term Marjolin ulcer dates to 1828 (Jean Nicolas Marjolin). Classic descriptions include villous/fungating projections, a firm granular texture or red, friable tissue that bleeds easily—features that mirror the frond‑like, bleeding edges seen in this case. The poster’s Historical Context panel (page 2) and Ulcer Evolution imagery illustrate this clinical trajectory and its diagnostic implications. [2, 4]
Red flags for SCC in pilonidal disease (from the case + classic descriptions)
Consider urgent biopsy when you see any of the following:
Persistent drainage or nonhealing after months of care.
Fissure‑like, full‑thickness tract with 3–4 cm depth or more.
Irregular, frond‑like/cauliflowering edges that bleed easily.
Rapid change in size (e.g., 3 cm → 6 cm over months).
Location consistent with pilonidal sinus and a longstanding mass that “ruptured.”
Possible bone involvement (clinical concern for sacral penetration).
Pearl: The poster opens with the maxim, “If a wound is not healing, biopsy it.” This applies with special urgency to chronic pilonidal disease.
Practical workflow (clinic‑friendly)
1) Reassess the “chronic pilonidal wound.”
Document size, depth, edge morphology, bleeding on contact, drainage, and pain; review duration and prior episodes of abscess/rupture. If red flags are present, do not delay biopsy.
2) Biopsy strategy.
Sample the edge and base to capture invasive fronts; avoid superficial curettage that yields only inflammatory debris. (The reported case used surgical biopsy, which diagnosed SCC invading the reticular dermis.) [3, 5]
3) While awaiting pathology, stabilize the wound.
The team in the case used dilute sodium hypochlorite (Dakin’s)–soaked packing with a foam dressing, a reasonable bridge to control bioburden and exudate without macerating the tract. [7, 8]
4) Positive result? Stage and refer quickly.
The reported plan was complete surgical excision with consideration of neoadjuvant therapy given lesion depth and risk of regional spread—both factors that can raise morbidity if surgery proceeds without down‑staging. [1, 3]
5) Close the loop on system barriers.
This patient’s multi‑month delay (missed appointment, ED revisits without biopsy) paralleled the lesion’s growth; establish fast‑track pathways for suspicious wounds to prevent similar gaps.
What clinicians should learn from this case
Transformation is uncommon but real. SCC arising in pilonidal sinus disease occurs at an estimated ~0.1% rate, enough to warrant vigilance in any prolonged, atypical course.
Edge architecture matters. “Frond‑like,” friable, or easily bleeding borders are classic malignant clues that should override assumptions about “routine” pilonidal disease.
Delays worsen the field. In just a few months, this wound doubled in length, with clinical concern for sacral involvement—changes that complicate resection and may necessitate neoadjuvant therapy.
A simple rule prevents misses: Biopsy any chronic, nonhealing pilonidal wound—especially after rupture—and escalate to surgical oncology promptly when SCC is confirmed.
FAQ (with concise clinician answers)
How common is squamous cell carcinoma from pilonidal sinus disease?
It’s rare, ~0.1%, but the consequences of missing it are high—hence the low threshold to biopsy nonhealing pilonidal wounds.
What clinical features should trigger an immediate biopsy?
A fissure‑like tract ≥3–4 cm deep, frond‑like or irregular edges, easy bleeding, progressive enlargement, and months of persistent drainage despite reasonable care.
What initial management is reasonable while awaiting pathology?
Bioburden/exudate control and atraumatic coverage—e.g., dilute sodium hypochlorite packing with a foam dressing—as used in the case. [7, 8]
If SCC is confirmed, what comes next?
Surgical excision is the plan reported here; however, with deep or expansive local disease, neoadjuvant therapy may be considered to reduce surgical morbidity and address regional risk.
Bottom line
In chronic pilonidal disease, don’t normalize a wound that keeps changing. The combination of deep fissuring, bleeding frond‑like edges, interval growth, and persistent drainage should prompt immediate biopsy and expedited oncologic management—before the window for a less morbid operation closes. [3, 5]
Medical education note: For clinicians; not a substitute for patient‑specific medical advice.
References
[1] Michalopoulos N, et al. Squamous cell carcinoma arising from chronic sacrococcygeal pilonidal disease. World J Surg Oncol. 2017. https://wjso.biomedcentral.com/articles/10.1186/s12957-017-1129-0
[2] Iqbal FM, Sinha Y, Jaffe W. Marjolin’s ulcer: a rare entity with a call for early diagnosis. BMJ Case Rep. 2015. https://upload.orthobullets.com/journalclub/pubmed_central/26177995.pdf
[3] Shah M, Crane JS. Marjolin Ulcer. StatPearls [Internet]. 2023 update. https://www.ncbi.nlm.nih.gov/books/NBK532861/
[4] Pekarek B, et al. A Comprehensive Review on Marjolin’s Ulcers: Diagnosis and Treatment. J Am Col Certif Wound Spec. 2012. https://pmc.ncbi.nlm.nih.gov/articles/PMC3601857/
[5] Khan K, et al. Marjolin Ulcer: A Comprehensive Review. Adv Skin Wound Care. 2020. https://nursing.ceconnection.com/ovidfiles/00129334-202012000-00003.pdf
[6] Pandey MK, Gupta P, Khanna AK. Squamous cell carcinoma arising from pilonidal sinus. Int Wound J. 2012. https://pmc.ncbi.nlm.nih.gov/articles/PMC7950348/
[7] Keyes M, et al. Dakin Solution. StatPearls [Internet]. 2023 update. https://www.ncbi.nlm.nih.gov/books/NBK507916/
[8] AHP Network. Wound Care Product Resource Guide – Dakin’s solution packing (short-term). https://ahpnetwork.com/clinical-resources/wound-care-tool-kit/wound-care-product-resource/
