Psoriasis & Skin Cancer | Dr. Zheng Jie (Dermatology) | CMCS Shanghai

About Dr. Zheng Jie

Dr. Zheng Jie is Director of Dermatology at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine — one of China's foremost dermatology departments and a national reference institution for psoriasis, autoimmune skin disease, and dermatological oncology. She is a nationally recognised leader in clinical dermatology, recognised for her expertise in biologic therapy for moderate-to-severe psoriasis, the management of autoimmune skin diseases, and the diagnosis and treatment of cutaneous malignancies arising in the context of chronic inflammatory skin disease. Dr. Zheng's practice is defined by the philosophy that chronic inflammatory skin disease and cutaneous malignancy are not independent events to be managed by separate specialists — that the chronic inflammation driving psoriasis and the malignant transformation occurring within psoriatic plaques share a common immunological substrate, and that treating one without understanding the other exposes the patient to avoidable risk. Her department at Ruijin Hospital has established one of China's most comprehensive dermatology programmes, integrating dermoscopy-guided lesion assessment, histopathological diagnosis, systemic immunomodulatory therapy, surgical oncology, and structured long-term surveillance into a unified care pathway for patients with complex combined inflammatory and oncological skin disease.

Case Overview

Mr. Thomas Brennan (pseudonym), a 65-year-old Irish retired worker based in Shanghai, presented with a 30-year history of plaque psoriasis and a two-month history of a rapidly enlarging, ulcerated, cauliflower-like lesion on his right lower leg at the site of a chronic psoriatic plaque. Dermoscopy demonstrated irregular squamous structures with dotted and glomerular vessels. Biopsy confirmed cutaneous squamous cell carcinoma (SCC) superimposed on psoriatic skin, staged T2N0M0. Serum SCC antigen was elevated at 2.5 ng/mL. A multidisciplinary team led by Dr. Zheng Jie recommended wide local excision of the SCC with 0.5–1 cm margins to subcutaneous fat, concurrent systemic methotrexate for psoriasis control, and topical calcipotriol and halometasone for non-operative psoriatic plaques. Post-operative histology confirmed clear margins with no lymph node involvement. At three months, no tumour recurrence was detected, and the patient's psoriasis had achieved near-complete remission with only residual post-inflammatory hyperpigmentation.

Patient Background

• Name / Nationality: Mr. Thomas Brennan (pseudonym) — Irish; 65-year-old retired worker based in Shanghai
• Age / Sex: 65-year-old male
• Chief Complaint: Recurrent generalised erythema and scaling for over 30 years; new right lower leg lesion with ulceration and pain for two months
• Psoriasis history: Diagnosed with plaque psoriasis over 30 years ago; seasonal pattern — worse in winter, improved in summer; intermittent treatment with topical corticosteroids, vitamin D3 analogues, and coal tar preparations; progressive worsening over the past five years with involvement of scalp, trunk, and bilateral extensor and flexor surfaces; associated pruritus
• New lesion history: Lesion appeared on a chronic psoriatic plaque on the right anterior lower leg two months prior; initially pea-sized, rapidly enlarging to pigeon-egg size; cauliflower-like surface; ulceration, bleeding, and pain; worsening over the past week with sleep disturbance and functional impairment
• Cardiovascular risk factors: Hypertension for 10 years, managed with nifedipine sustained-release; 40-year smoking history (20 cigarettes per day); alcohol consumption approximately 100 mL of spirits per day for 30 years
• Examination — general: Stable vital signs; alert and oriented; moderate nutritional status
• Examination — skin: Widespread erythematous plaques with silvery scaling on scalp, trunk, and bilateral extensor and flexor surfaces; some plaques confluent; Auspitz sign positive (pinpoint bleeding on scale removal) — consistent with plaque psoriasis. Right anterior lower leg: approximately 3 cm × 4 cm cauliflower-like exophytic lesion with serous exudate and haemorrhagic crust; surrounding erythema and oedema; marked tenderness on palpation

Diagnostic Workup

Laboratory Investigations

• Full blood count: WBC 8.5 × 10⁹/L, neutrophils 65%, haemoglobin 130 g/L, platelets 200 × 10⁹/L — within normal limits; no haematological contraindication to methotrexate
• Biochemistry: Liver function, renal function, fasting glucose, and lipids all within normal range — baseline established before initiating methotrexate
• SCC antigen (SCC-Ag): 2.5 ng/mL (reference range <1.5 ng/mL) — mildly elevated; consistent with cutaneous SCC; useful as a baseline for post-treatment surveillance

Dermoscopy

• Right lower leg lesion: Irregular squamous structures; dotted and glomerular vessels — vascular pattern characteristic of cutaneous squamous cell carcinoma; no features of melanocytic lesion or basal cell carcinoma
• Psoriatic plaques (other sites): Regular dotted vessels on erythematous background with white scaling — consistent with psoriasis; no atypical vascular patterns at other sites

Histopathology — Right Lower Leg Lesion

• Epidermal changes: Hyperkeratosis with parakeratosis; acanthosis; downward elongation of rete ridges
• Dermal infiltrate: Dense lymphocytic and histiocytic infiltrate in the superficial dermis
• Malignant features: Disordered epidermal cell arrangement; nuclear enlargement and hyperchromasia; cellular atypia; pathological mitotic figures — diagnostic of cutaneous squamous cell carcinoma
• Staging: T2N0M0 — tumour greater than 2 cm in maximum dimension; no regional lymph node involvement on clinical and imaging assessment; no distant metastasis

Histopathology — Psoriatic Plaques (Other Sites)

• Epidermal changes: Hyperkeratosis; parakeratosis; thinning or absence of the granular layer; acanthosis; elongated rete ridges
• Dermal changes: Dilated and tortuous capillaries in the dermal papillae; lymphocytic infiltrate — consistent with plaque psoriasis; no atypia or malignant features at other sites

Dr. Zheng's diagnostic assessment: The dermoscopy told us immediately that this was not a psoriatic plaque that had become inflamed or infected. The vascular pattern — glomerular vessels in an irregular distribution — is the dermoscopic signature of squamous cell carcinoma. Psoriasis shows regular dotted vessels on a red background. This lesion showed irregular glomerular vessels with a disorganised squamous surface. We biopsied the same day. The pathology confirmed SCC arising within a psoriatic plaque. This is a recognised but underappreciated complication of long-standing psoriasis — the chronic inflammatory microenvironment within a psoriatic plaque creates conditions that favour malignant transformation. The SCC-Ag was elevated, which gives us a baseline to track after surgery. The staging workup showed no nodal or distant disease — T2N0M0. This is resectable with curative intent.

Multidisciplinary Team Discussion and Treatment Strategy

The MDT convened by Dr. Zheng Jie included dermatology and oncology. The consensus was that the SCC required surgical excision as the primary treatment, and that the psoriasis required concurrent systemic therapy — both because the disease was severe and functionally impairing, and because surgical trauma to psoriatic skin carries a risk of Koebner phenomenon, in which new psoriatic plaques develop at sites of skin injury.

SCC treatment: Wide local excision with 0.5–1 cm margins to the level of subcutaneous fat — the standard surgical approach for T2 cutaneous SCC. Post-operative adjuvant radiotherapy or chemotherapy to be determined by final pathology margins and lymph node status.

Psoriasis treatment — systemic: Methotrexate (MTX) weekly oral dosing, dose adjusted for body weight and renal function; concurrent folic acid supplementation to reduce MTX toxicity; regular monitoring of full blood count and liver and renal function.

Psoriasis treatment — topical: Calcipotriol ointment and halometasone cream applied twice daily in alternation to non-operative psoriatic plaques; topical therapy extended to peri-incisional psoriatic skin after wound healing.

Immunosuppression consideration: Biologic therapy (IL-17 or IL-23 inhibitors) was discussed but deferred given the concurrent SCC diagnosis — biologic immunosuppression in a patient with active cutaneous malignancy carries a theoretical risk of accelerating tumour progression or impairing immune surveillance. MTX was selected as the systemic agent of choice given its established safety profile in this context and its dual anti-inflammatory and antiproliferative properties.

Operative Procedure

Wide Local Excision of Cutaneous SCC

Pre-operative planning: Excision margins marked at 0.5–1 cm from the visible tumour edge circumferentially; depth planned to subcutaneous fat to ensure adequate deep margin. The surrounding psoriatic skin was assessed clinically and dermoscopically to confirm no additional suspicious lesions within the planned excision field.

Anaesthesia: Local anaesthesia with adrenaline infiltration; patient comfortable throughout.

Excision: Elliptical excision encompassing the tumour with planned margins; dissection carried to the level of subcutaneous fat. Specimen oriented and submitted for histopathological margin assessment.

Wound closure: Primary closure achieved with interrupted sutures; wound edges approximated without tension. Non-adherent dressing applied.

Intraoperative assessment: Specimen macroscopically confirmed to include the entire visible tumour with surrounding normal-appearing skin margins.

Final histopathology: Clear margins confirmed — no tumour at any resection margin; no lymphovascular invasion; no perineural invasion. No sentinel lymph node biopsy performed given T2N0 staging and absence of high-risk histological features. Adjuvant radiotherapy and chemotherapy not indicated.

Dr. Zheng's operative note: The margin selection for cutaneous SCC is a balance between oncological adequacy and functional reconstruction. For a T2 lesion on the lower leg, 0.5 to 1 cm is the evidence-based margin — wide enough to clear the tumour with high probability, narrow enough to allow primary closure without a flap or graft. We marked the margins before infiltrating the local anaesthetic, because the adrenaline causes vasoconstriction that can distort the tissue planes and make the tumour edge harder to define. The excision went to subcutaneous fat — the deep margin is as important as the lateral margin for SCC. The pathology came back clear on all margins. No adjuvant treatment needed. The surgery is the cure for this stage of disease.

Post-operative Management and Outcomes

SCC Surveillance

• Wound healing: Primary wound healing achieved; no infection, haematoma, or dehiscence; sutures removed at day 10–14
• SCC-Ag monitoring: Serum SCC-Ag trended down from 2.5 ng/mL at baseline toward normal range at follow-up — consistent with complete tumour clearance
• Recurrence surveillance: Regular clinical and dermoscopic examination of the excision site and regional lymph nodes at follow-up visits; no recurrence or nodal disease detected

Psoriasis Treatment Response

• Weeks 1–2 on MTX: No significant adverse effects; treatment tolerated well
• Week 3: Nausea and vomiting — managed with antiemetics and dietary adjustment; MTX dose maintained; folic acid continued; liver and renal function and full blood count remained within normal limits throughout
• Topical therapy response: Progressive thinning of psoriatic plaques at non-operative sites; scaling reduced; pruritus significantly improved within four weeks of initiating calcipotriol and halometasone combination
• 3-month assessment: Near-complete psoriasis remission — the majority of plaques had cleared; residual post-inflammatory hyperpigmentation only; patient reported significant improvement in sleep quality, comfort, and daily function
• Koebner phenomenon: No new psoriatic plaques developed at the surgical wound site — attributed to effective systemic MTX suppression of the psoriatic inflammatory response perioperatively

Expert Commentary — Dr. Zheng Jie

1. Psoriasis as a Pro-Oncogenic Inflammatory Microenvironment

The association between long-standing psoriasis and cutaneous malignancy — particularly squamous cell carcinoma — is supported by epidemiological data and mechanistic evidence. Psoriatic plaques are characterised by a chronic inflammatory microenvironment driven by TNF-α, IL-17, IL-23, and other pro-inflammatory cytokines that promote keratinocyte hyperproliferation, impair apoptosis, and generate reactive oxygen species that cause DNA damage. Over decades, this sustained genotoxic stress within the plaque creates conditions that favour the accumulation of oncogenic mutations in keratinocytes — the same cells that give rise to squamous cell carcinoma. The risk is compounded in patients who have received long-term topical coal tar preparations, PUVA phototherapy, or systemic immunosuppressants — all of which have independent carcinogenic or immunosuppressive effects. In this patient, 30 years of chronic plaque inflammation, combined with 40 years of smoking — an independent risk factor for cutaneous SCC — created a cumulative oncogenic burden that manifested as SCC within the most chronically inflamed plaque. The clinical lesson is that any new or changing lesion within a psoriatic plaque in a long-standing psoriasis patient must be evaluated with dermoscopy and biopsy, not assumed to be a psoriatic flare.

2. Dermoscopy in Psoriatic Skin: Distinguishing Inflammation from Malignancy

Dermoscopy is the essential tool for evaluating new or changing lesions in psoriatic skin, because the clinical appearance of an inflamed psoriatic plaque and an early SCC arising within a plaque can be indistinguishable to the naked eye. Both present as erythematous, scaling, crusted lesions. The dermoscopic distinction is in the vascular pattern. Psoriasis characteristically shows regular dotted vessels — small, round, uniformly distributed red dots corresponding to the dilated capillary loops in the dermal papillae — on a light red background with white scaling. Cutaneous SCC shows a fundamentally different vascular pattern: irregular, tortuous glomerular vessels — larger, more complex, and distributed in a disorganised pattern — often associated with white circles or structureless areas corresponding to keratin pearls. When a lesion in a psoriatic patient shows glomerular vessels in an irregular distribution, SCC must be excluded by biopsy regardless of the clinical appearance. In this case, the dermoscopic pattern was unambiguous — the biopsy confirmed what the dermoscopy predicted.

3. Methotrexate in Psoriasis Concurrent with Cutaneous Malignancy: Balancing Immunosuppression and Oncological Safety

The management of psoriasis in a patient with concurrent or recent cutaneous malignancy requires careful selection of the systemic agent. Biologic therapies — particularly TNF-α inhibitors and IL-17 inhibitors — are the most effective systemic treatments for moderate-to-severe psoriasis, but they carry a theoretical risk of impairing immune surveillance of residual or recurrent tumour cells. The evidence base for biologic use in patients with a history of non-melanoma skin cancer is evolving, but current guidelines recommend caution, particularly in the perioperative period and in patients with incompletely treated malignancy. Methotrexate occupies a different risk profile: it is an antifolate that suppresses rapidly dividing cells — both the hyperproliferating keratinocytes of psoriasis and, at higher doses, malignant cells — without the targeted immunosuppression of biologics. Its long-term safety in patients with a history of cutaneous SCC is better established than that of biologics. In this patient, MTX was the appropriate systemic choice: effective for psoriasis control, perioperatively protective against Koebner phenomenon at the surgical site, and oncologically safer than biologic immunosuppression in the context of a recently excised SCC.

4. The Koebner Phenomenon: Why Psoriasis Control Is a Surgical Priority

The Koebner phenomenon — the development of new psoriatic plaques at sites of skin trauma — is a well-recognised complication of surgery in psoriatic patients. The mechanism involves the activation of the psoriatic inflammatory cascade by the physical disruption of the skin barrier, recruiting T cells and dendritic cells to the wound site and triggering the cytokine cascade that drives plaque formation. In a patient undergoing excision of a cutaneous SCC within a psoriatic plaque, the Koebner phenomenon at the surgical wound would not only impair wound healing but would create a new inflammatory microenvironment at the excision site — precisely the environment that contributed to the original malignant transformation. Preventing Koebner phenomenon at the surgical site is therefore both a wound healing priority and an oncological one. Systemic MTX, initiated before surgery and continued through the healing period, suppresses the psoriatic inflammatory response systemically — reducing the likelihood that the surgical wound will trigger a new plaque. In this patient, no Koebner phenomenon occurred at the excision site — a direct consequence of effective perioperative psoriasis control.

How CMCS Shanghai Coordinated This Case

CMCS Shanghai supported Mr. Brennan and his family from initial presentation through three-month follow-up, including: urgent coordination of dermatology consultation with Dr. Zheng Jie at Ruijin Hospital, Shanghai Jiao Tong University with priority appointment scheduling given the rapidly enlarging and ulcerated lesion; bilingual review of all prior psoriasis treatment records, topical and systemic therapy history, and phototherapy records with clinical summary for the MDT; coordination of dermoscopy assessment, full blood count, biochemistry, and SCC-Ag with bilingual results communication; coordination of skin biopsy at the right lower leg lesion and psoriatic plaque sites with bilingual histopathology report translation and staging interpretation; bilingual interpretation throughout all MDT discussions involving dermatology and oncology; pre-operative coordination including local anaesthesia consent, excision margin planning discussion, and bilingual surgical consent support; real-time updates to the patient's wife and his GP in Dublin during the operative period; post-operative wound care coordination including bilingual dressing instructions, suture removal scheduling, and wound healing monitoring; methotrexate initiation coordination including pharmacy prescription support, folic acid supplementation, and bilingual monitoring schedule for full blood count and liver and renal function; antiemetic management coordination when gastrointestinal side effects emerged at week three; topical therapy coordination including calcipotriol and halometasone prescription and bilingual application instructions; three-month follow-up coordination including clinical and dermoscopic examination, SCC-Ag repeat testing, and results communicated to the patient's dermatologist and GP in Ireland; and establishment of a long-term skin cancer surveillance protocol with six-monthly full skin examination and annual SCC-Ag monitoring.

For international patients with psoriasis, cutaneous malignancy, or complex combined inflammatory and oncological skin disease requiring specialist dermatological care in Shanghai, Dr. Zheng Jie's team at Ruijin Hospital, Shanghai Jiao Tong University represents dermatology expertise at the international frontier — combining dermoscopy-guided diagnosis, surgical oncology, systemic immunomodulatory therapy, and structured long-term surveillance to achieve tumour clearance and disease remission in patients with complex multisystem skin disease. CMCS ensures that expertise is accessible: in the patient's language, with overseas physicians informed at every step, from the first dermoscopic assessment through long-term oncological surveillance.

This case report is de-identified and published for educational purposes. All clinical details have been anonymized in accordance with patient privacy standards. CMCS Shanghai is a medical concierge service and does not provide direct medical care.