Introduction: Leprosy is a chronic infectious granulomas disease caused by Mycobacterium leprae that can manifest as a wide variety of immunological and clinical features.

Case summary: Here, we describe the case of a woman with clinical characteristics of borderline tuberculoid (BT) leprosy that manifested as 3 asymmetric skin lesions involving her hip and lower limbs. This unusual presentation was initially misdiagnosed as sarcoidosis because noncaseating granulomas are a histopathological feature of both diseases. Differentiation and the diagnosis of BT leprosy was achieved using real-time polymerase chain reaction (PCR) to amplify an M leprae specific DNA sequence and to detect serum antibodies specific to M leprae antigens. Accordingly, a 6-month course of multidrug therapy led to a marked improvement in the skin lesions.

Conclusion: The use of auxiliary tests including real-time PCR to amplify an M leprae-specific DNA sequence, enzyme-linked immunosorbent assay, and dipstick detection of serum antibodies specific to M leprae antigens are good methods to obtain a correct diagnosis of BT leprosy.

The authors report no conflicts of interest.

Figure 1

Figure 1

Macroscopic presentation of the plaques....

Figure 1

Macroscopic presentation of the plaques. (A) Palm-sized plaques are shown on the right...

Figure 2

Figure 2

Microscopic observations of the skin...

Figure 2

Microscopic observations of the skin biopsies. (A) Under ×ばつ magnification, thinning of the...

Figure 3

Figure 3

Recovery of the skin lesions...

Figure 3

Recovery of the skin lesions following multidrug therapy (MDT). After a 6-month course...

Figure 4

Figure 4

Samples from the case generate...

Figure 4

Samples from the case generate (A) a positive band in a rapid lateral...