Cutaneous T-cell lymphoma developing in surgical scars post cardiac surgery: A case study

Abstract

Cutaneous T-cell lymphomas are a class of non-Hodgkin lymphomas characterized by the infiltration of malignant T cells into the skin. Their precise pathogenesis remains incompletely understood, but persistent and specific antigen stimulation of skin-homing CD4+ memory T cells by external or internal factors, combined with an inflammatory cytokine-rich tissue microenvironment, may be critical in the development of cutaneous T-cell lymphomas. We present herein a case of primary cutaneous T-cell lymphoma arising in two surgical scars that developed 6 months post-operatively and were successfully treated with external beam radiotherapy. This case highlights the notion that primary cutaneous T-cell lymphoma can develop locally at the site of injury/foreign body within a relatively short time post trauma/surgery. This work contributes to the literature of cutaneous T-cell lymphomas arising after a trauma, surgery, or a foreign body.

Introduction

Cutaneous T-cell lymphomas (CTCLs) are a class of non-Hodgkin lymphomas characterized by the infiltration of malignant T cells in the skin.^1–3 The exact pathogenesis of CTCL remains unknown,^4–7 but persistent antigen stimulation of skin-homing CD4+ or in fewer cases CD8+ memory T cells by external/internal factor(s) is one putative plausible mechanism.^8,6,9–11 Mounting evidence suggests that chronic antigenic stimulation drives the immune system to proliferate and accumulate activated T cells.^9,12–14 Multiple external environmental factors (e.g. bacterial infections, foreign bodies, chemical agents or medications, herbicides, and industrial materials) have been associated with CTCL, but the exact antigens and triggers remain undefined. ¹⁵

We report herein a patient who developed new plaques of primary CTCL postoperatively in surgical scars, which responded well to electron beam radiotherapy.

Case

The patient provided informed consent to publish the case and associated images. An 82-year-old Caucasian retired mechanic with a personal history of hypertension, benign prostatic hyperplasia, and gastroesophageal reflux underwent an aortic valve replacement. Six months after surgery, he developed two violaceous indurated dermal plaques in the postoperative surgical sternotomy and upper abdominal scars, the sites of the surgical incision to enable the insertion of defibrillation wires. The patient had no B-symptoms and no previous history of any malignancies, although there was a family history of melanoma and lung cancer. He is an ex-smoker (40 pack-years) and consumed alcohol socially on occasion. His regular medications included amlodipine, finasteride, low-dose aspirin, pantoprazole, and vitamin D. On examination, two indurated violaceous plaques were noted at the superior edge of the sternotomy scar and on the left distal aspect of the central abdominal surgical scars (Figure 1(a)). The clinical differential diagnosis included a cutaneous lymphoproliferative disorder, sarcoidosis, keloid scars, reactive lymphoid hyperplasia, or a mycobacterial infection along with other rarer causes of violaceous dermal plaques. ¹⁶ A 4-mm punch biopsy under local anesthesia was obtained from the superior aspect of the sternal plaque, and intralesional triamcinolone (5 mg/mL) was administered to the other plaque since infectious causes were deemed to be less likely. This initial biopsy was suggestive of a primary CTCL. The patient was referred to a dermatology and medical oncology ambulatory clinic for further evaluation.

Figure 1.

Clinical images (a) initial presentation: indurated violaceous sternal plaque at the superior edge of the sternotomy scar (arrow), and second indurated plaque at the left distal aspect of the central abdominal scar (arrow). (b) Three months post-targeted radiotherapy and topical steroids application; note the partial regression of the sternal plaque and complete regression of the abdominal plaque resulting in an ivory color scar.

Over the period of subsequent 3 months, the patient reported that the plaques were growing in size and becoming pruritic. A 4-mm punch biopsy from the sternum was repeated and demonstrated a primary CTCL, stage T2N0. He was referred to a specialized CTCL multidisciplinary team in May 2022, where an excision of the central abdominal indurated plaque was performed under local anesthesia. The excised specimen measured 3.6 × 1.3 × 0.3 cm, and the plaque measured 2 × 1 cm. Microscopic examination revealed a prominent multinodular and diffuse superficial, mid and deep dermal infiltrate of atypical T lymphocytes with epidermotropism and rare Pautrier microabscesses (Figure 2(a)–(c)). Immunohistochemistry showed the cells were predominantly CD2-, CD3-, and CD4-positive with loss of CD5 and CD7; 10%–20% of cells were CD30-positive and the Ki-67 proliferation rate was estimated at 10%, consistent with a primary CTCL with features of mycosis fungoides (MF) (Figure 2(d)–(g)). Molecular analyses done on both the punch biopsy and the excision revealed the presence of clonal T cells. The patient was prescribed a potent topical steroid (desoximetasone ointment) to be applied twice daily to the affected skin. A positron emission tomography (PET) scan demonstrated hypermetabolic (standardized uptake value or SUV of 3.5) cutaneous/subcutaneous lesions in the anterior thorax overlying the sternum and upper quadrant of the abdomen, corresponding to the biopsy-proven CTCL. No other suspicious lesions or lymph nodes were detected.

Figure 2.

Microscopic and immunohistochemical findings. (a) Low power micrograph of the skin excision showing the prominent lymphoid infiltrate. (b) Medium power of the deep infiltrate composed of small to medium monotonous lymphoid cells. (c) High power of the intraepidermal Pautrier microabscess. (d–g) Immunostains for CD3, CD4, CD8, and CD7, respectively: note the predominance of CD4+ over CD8+ cells and loss of CD7 that stains only residual non-neoplastic T-cells.

He was referred to radiation oncology where he received a course of targeted electron beam radiotherapy (30 Gy given in 10 fractions). At follow-up 3 months later, no new lesions appeared and the existing plaques were regressing with the continued use of the desoximetasone ointment (Figure 1(b)). The patient remains well and is being followed in dermatology and radiation oncology clinics every 3–4 months.

Discussion

External environmental factors are thought to play a role in the pathogenesis and progression of CTCL.^9,17–19 One theory is that specific antigen presentation and long-standing antigenic stimulation, combined with an inflammatory cytokine-rich microenvironment, may play critical roles in the development of CTCL.

A case series by Paul and Duvic ²⁰ reported four male patients who developed primary CTCL, specifically MF, at the site of skin trauma that had occurred over 10 years previously: the traumas included implanted gravel after a running injury, injection of super glue®, exposure to poison oak, and a traumatic hematoma that required multiple surgical interventions.

In another series, Lebas et al. ²¹ reported three cases of de novo CTCL lesions appearing on previously non-involved skin after cutaneous trauma in patients with pre-existing MF elsewhere, and suggested a Koebnerization effect; all three patients had been treated for their MF with topical steroids, interferon-alpha, or phototherapy, and developed MF in the new sites of repeated trauma.

In conclusion, we report here a case of a primary CTCL arising at the site of two surgical scars 6 months after surgery, contributing to the existing literature of CTCL arising after trauma, a foreign body exposure, or implantation. ²⁰ Persistent antigenic stimulation, including from an environmental agent, may induce an inflammatory reaction that can evolve into clonal T-cell proliferation. CTCL arising at site of skin trauma months or years later supports the hypothesis of Tan et al. ⁸ as well as the concept of Koebnerization of new CTCL lesions in patients with pre-existing CTCL. ²¹ The unusual feature in our patient is the short time interval between surgery and the CTCL.