Sir,

Pyogenic granuloma-like Kaposi’s sarcoma is a vascular tumor caused by HHV8. It may be challenging in diagnosis. Dermoscopy is a valuable tool in the diagnosis. Herein, we report the case of a female patient with pyogenic granuloma-like Kaposi’s sarcoma.

A 65-year-old female patient with no relevant medical history presented with a one-month history of a painful tumor between the first and second toe of the right foot that had been quickly increasing in size. The patient received antibiotics without any improvement. A physical examination revealed the presence of a red firm mass, approx. 3 × 2 cm in diameter (Fig. 1a). Dermoscopy revealed reddish and yellowish homogeneous areas and the “sticky fiber” sign was noted (Fig. 1b). A surgical resection was performed. Histological examination of the mass showed nodules of spindles cells mixed with red blood cells (Fig. 1c); Immunochemistry was positive for CD34 and HHV8, consistent with Kaposi’s sarcoma (Fig. 1d). Further radiologic investigation showed no other signs suggestive of Kaposi’s sarcoma. An HIV screening test was negative. No recurrence during a one-year follow-up was observed.

Figure 1: (a) Red, firm tumor, approx. 3 × 2 cm in diameter. (b) Dermoscopy revealing reddish and yellowish homogeneous areas with the “sticky fiber” sign. (c) Histological findings showing spindle cells mixed with red blood cells. (d) Immunohistochemistry staining for HHV8.

Kaposi’s sarcoma (KS) is a low-grade vascular malignancy. Four epidemiological forms have been described: classic KS, most commonly affecting elderly males of middle eastern and Mediterranean ancestry, endemic KS, iatrogenic KS in association with immunosuppression, and HIV/AIDS-associated KS [1].

PG-like KS has been reported in patients with HIV-positive and HIV-negative status. In the literature, it was found on the hands in three patients and on the sole in two patients [2,3]. Dermoscopy is a valuable tool in the diagnosis of Kaposi’s sarcoma. The most common dermoscopic features of KS are white lines, white clods, a polychromatic color change, or a rainbow pattern. In our case, we noted the presence of yellowish and reddish homogeneous areas. PG-like KS may be challenging in diagnosis because of overlapping histologic features, such as nodular prominence, ulceration, and inflammation. HHV-8 is the causative agent in all forms of KS, and immunohistochemical staining with HHV8 antibody is highly sensitive and specific to KS [4].

Physicians should be aware of this rare variant mimicking pyogenic granuloma. Immunohistochemistry should be performed to exclude Kaposi’s sarcoma.

REFERENCES

1. Urquhart JL, Uzieblo A, Kohler S. Detection of HHV-8 in pyogenic granuloma-like Kaposi sarcoma. Am J Dermatopathol. 2006;28:317–21.

2. Ho B, Rinaldi G, Khan I, Szakacs S. Pyogenic granuloma-like Kaposi sarcoma presenting in an HIV-negative man who has sex with men. BMJ Case Rep. 2020;13:e237420.

3. Cabibi D, Giannone AG, Guarnotta C, Schillaci O, Franco V. D2-40 negative pyogenic granuloma-like Kaposi’s sarcoma:Diagnostic features and histogenetic hypothesis of an uncommon skin tumor in HIV-negative patients. Pathol Res Pract. 2015;211:528-32.

4. Hbid O, Belloul L, Fajali N, Ismaili N, Duprez R, Tanguy M, et al. Kaposi’s sarcoma in Morocco:A pathological study with immunostaining for human herpesvirus-8 LNA-1. Pathology. 2005;37:288-95.