Squamous cell carcinoma arising in chronic hidradenitis suppurativa: a lethal complication to be avoided

Hidradenitis suppurativa (HS) is a common chronic inflammatory skin disease with recurrent abscesses, fistulas and scarring on the areas where apocrine sweat glands are present [1]. The transformation of squamous cell carcinoma (SCC) from severe, long-lasting HS is an unusual and overlooked complication that may convert a potentially curable disease into a lethal one [2].

A 59-year-old man was referred to us with ulcers on scarred buttocks of two years’ duration. When he was 30 years old, he had suffered relapsing papules or deep-seeded nodules on the face, scalp and the intertriginous areas that spontaneously coalesced and ruptured, producing a purulent discharge. They then healed with resulting fibrosis. Treatments with multiple antibiotics, isotretinoin and corticosteroids yielded no improvement. Two years prior to this consultation, the patient noticed that several recalcitrant ulcers had developed on the buttocks, with increase in discharge, bleeding and a foul smell; he began photodynamic therapy with 5-aminolevulinic acid for these conditions. He was a heavy smoker, and his past medical history was noncontributory. His body mass index (BMI) was 25.3. On examination, interconnecting abscesses, sinuses, fistulas and fibrotic scar tissue were observed, affecting both sides of the buttocks (Figure 1(A), Hurley stage III). Additionally, the exophytic crateriform neoplasm was more than 4 cm in diameter. Linear, disfiguring scars were observed on the face, the scalp, the axillae and the chest (Figure 1(A–D)). Inguinal lymphadenopathy was palpable. A biopsy of the margin of the ulcerated tissue showed a moderately differentiated SCC. Positron emission tomography-CT imaging showed metastasis to the pelvic floor. He was diagnosed with SCC following HS due to the clinical scenario. The patient refused operative management, instead opting for palliative chemotherapy, and died 5 months after the metastatic SCC diagnosis.

Figure 1. Interconnecting abscesses, sinuses, fistulas, and fibrotic scar tissue were observed affecting both sides of the buttocks (Hurley stage III). The tumor was exophytic with a central crater and bleeding (A). Linear, disfiguring scars and black comedones were seen on the chest (B), the scalp (C) and the axillae (D).

HS is commonly encountered and managed by general practitioners, dermatologists and other specialists [3]. It is a debilitating disease characterized by chronic inflammation, recurrent abscesses, nodules and fistulae over apocrine gland-bearing areas [3]. The prevalence of HS has been estimated to be 1–4%. It usually begins in the second and third decades of life, and ∼35–40% of HS patients have a positive family history [3,4].

HS is marked by intermittent periods of progression and amelioration. The disease begins as clusters of chronic abscesses, which may rupture and develop intradermal or subcutaneous fistulae in the axillary, inguinal, chest, scalp and anogenital regions [4]. A very common sequela is the formation of chronic scars and fibrosis. Along with HS, acne conglobate and perifolliculitis capitis abscendens et suffodiens coexist as parts of the follicular occlusion triad. Mutations in the g-secretase-Notch signaling pathway contribute at least partially to both familial and spontaneous cases. One theory suggests that an aberrant immune system may respond to commensal microbes in HS, leading to the production of antimicrobial peptides and the recruitment of TNF-a, IL-1b, IL-17 and other cytokines, which in turn give rise to hyperkeratotic plugs of the follicular infundibulum and subsequent activation of inflammation by the keratin released in the dermis due to its rupture [3].

There are multiple risk factors for HS. Individuals, especially with severe HS, smoke cigarettes at rates that well exceed the general population. Elevated nicotine intakes are thought to promote the formation of follicular plugging possibly by inducing chemotaxis of neutrophils [3,5]. At present, encouraging smoking cessation has been proven to be beneficial to the HS patient. Meanwhile, updated literature demonstrates obesity as a paramount risk factor, probably mediated by the concomitant circumstances in sweat retention, maceration, friction and altering hormonal secretion [3,5,6]. Hence, cessation of smoking and reducing BMI should be an integral parts of HS management to prevent its earlier development and exacerbation. Poorly controlled HS may result in a variety of complications, including chronic suppuration, fistula formation, diffuse fibrosis and malignant transformation in the areas of chronic inflammation [3,7]. The incidence of malignant transformation in HS is predicted to be 3.2%, and the average age at transformation is ∼52 years [8]. To date, more than 70 cases of SCC have been documented among HS patients at ∼10 years after the HS diagnosis [9]. Although HS is more prevalent in females, a male preponderance in SCC transformation has been revealed. There is a consensus that long-lasting HS and involvement of the buttocks and perineal areas increase the risk of malignant degeneration [1]. Although remission of HS is common after drainage of the abscesses, the risk of malignant transformation suggests that curative resection of all sinus tracks is preferable to prolonged medical treatment. Moreover, any tissue excised from an HS should be evaluated thoroughly by a pathologist.

This intriguing case is presented to highlight the need for greater clinical awareness that long-standing HS on the buttocks usually has greater malignant potential and should not be treated conservatively.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

The study was financially supported in part by the National Natural Science Foundation of China [Grant No. 81173400].