The Spectrum of Underlying Causes of Iatrogenic Kaposi's Sarcoma in a Large Series: A Retrospective Study

Abstract

Background: The frequency of clinicoepidemiological variants of Kaposi's sarcoma (KS) differs markedly throughout the world. The iatrogenic variant is mainly associated with the use of immunosuppressive therapy.

Aims: We aimed to investigate the distribution of KS variants in our practice and elucidate the underlying causes of iatrogenic KS.

Methods: Consecutive KS patients seen in a single tertiary center were grouped according to the tumor variants and iatrogenic KS patients were evaluated about associated conditions.

Results: Among 137 patients, classic variant was the most frequent presentation (n = 88), followed by iatrogenic (n = 37) variant. Among the iatrogenic group, ten were transplant recipients. In 16 iatrogenic KS patients, systemic corticosteroid was used, in four for myasthenia gravis (MG) and in three for rheumatoid arthritis. In three patients, KS developed under topical corticosteroid (TC) treatment. Among iatrogenic KS patients, ten of them had a second primary neoplasm and one had congenital immunodeficiency syndrome.

Conclusions: Our study revealed one of the highest rates for iatrogenic KS (27%) reported in the literature. Besides well-known causes, relatively frequent association with MG was remarkable. Usage of different forms of TCs was the cause of KS in a few cases.

Keywords: Corticosteroid; Kaposi's sarcoma; iatrogenic; myasthenia gravis; mycosis fungoides.

Figure 1

The distribution of 137 Kaposi's sarcoma patients according to clinicoepidemiological variants

Figure 2

(a) A solitary nodule of Kaposi's sarcoma in a patient with mycosis fungoides (Table 2, Patient 4). (b) Plaque lesions of Kaposi's sarcoma on the foot and verrucae on the hand in a child with congenital immunodeficiency (Table 3, Patient 19). (c) Verrucous plaque of Kaposi's sarcoma on the dorsum of the foot in a patient with myasthenia gravis (Table 3, Patient 2). (d) Large plaque of Kaposi's sarcoma covering the lower leg in a patient with myasthenia gravis (Table 3, Patient 1). (e) Large tumor of Kaposi's sarcoma on the tongue of a patient with myasthenia gravis (Table 3, Patient 1). (f) Papules and nodules of Kaposi's sarcoma on the trunk occurred after liver transplantation (Table 1, Patient 7)

Figure 3

(a and b) Regression of papulonodular Kaposi's sarcoma lesions on the lower leg in a patient with liver transplantation after switch of cyclosporine to sirolimus. Postinflammatory hyperpigmentation is noticeable (Table 1, Patient 7). (c and d) Complete regression of Kaposi's sarcoma lesions on the leg in a patient with Crohn's disease after cessation of systemic corticosteroid (Table 3, Patient 4)

Figure 4

(a) Conjunctival lesion of Kaposi's sarcoma located on the junctional area between normal epithelium containing numerous goblet cells and tumor area in upper right (H and E, ×100) (Table 3, Patient 2). (b) Higher magnification from tumor area shows spindle cell fascicles and slit-like small vascular spaces filled with erythrocytes (H and E, ×400). (c) Conjunctival tumor of another patient causing a small nodule surrounded by epithelial parts (H and E, ×100) (Table 3, Patient 17). (d) The nodule is composed of interlacing bundles of spindle cells and many tiny vascular spaces seen in higher magnification (H and E, x400)