Table of Content


Autumn 2020, Vol. 28 No. 3

Hong Kong J. Dermatol. Venereol. (2020) 28, 128-129

Dermato-venereological Quiz

Dermato-venereological Quiz

HF Cheng 鄭學輝 and M Chau 周慧璇


A Filipino domestic home-helper in her mid-30's presented with a few months' history of nodules over her trunk and limbs (Figures 1 & 2). The lesions were neither itchy nor painful. She had received no treatment. She was otherwise well, and her vision and appetite were normal. Her past medical health was unremarkable. A skin biopsy was performed from one of the back nodules.

Figure 1 Infiltrated facial skin lesions.   Figure 2 Skin nodules over the limb.


  1. What are the clinical differential diagnoses?
  2. What histopathological reaction pattern is shown in Figures 3a and 3b?
  3. What is shown in Figure 3c? What are the terms used to describe the histopathological features illustrated here?
  4. Why is there a difference in the staining pattern between the two histochemical stains in Figure 4a (Ziehl-Neelsen stain) and 4b (Wade-Fite stain)?
  5. What is the management?
Figure 3 (a) Skin biopsy. Haematoxylin & eosin. Magnification x40; (b) Skin biopsy. Haematoxylin & eosin. Magnification x100; (c) Skin biopsy. Haematoxylin & eosin. Magnification x400.
Figure 4 (a) Skin biopsy. Ziehl-Neelsen stain, magnification x100; (b) Wade-Fite stain under oil immersion, magnification x1000.