Coexistence of Two Different Morphological Forms of Cutaneous Tuberculosis: A Report of Two Cases.

Sir,

Tuberculosis (TB) remains a major health problem and cutaneous TB at times difficult to diagnose because of its varied, atypical presentation, and multifarious histopathological findings. The clinical spectrum of cutaneous TB depends on route of infection, immune status of the patient, and previous sensitization with Mycobacterium tuberculosis.[1] Simultaneous presence of two different forms of cutaneous TB in an individual is uncommon. We here report two cases of coexistent TB verrucosa cutis (TVC) and lupus vulgaris (LV).

First case, a 20-year-old male farmer presented with two skin lesions at two different sites. The first lesion appeared over the left sole 2 years ago. After 6-8 weeks, the patient noticed the second lesion over the medial aspect of the left forearm. On examination, single large, nontender, indurated, verrucous, well-defined plaque measuring around 9 cm × 8.5 cm was seen over the left sole and an irregular brownish plaque with hypopigmentation and atrophy in center was noticed over the medial aspect of the left forearm [Figure 1]. Latter showed apple jelly nodules on diascopy and the patient was Bacillus Calmette–Guérin vaccinated. Lesions were suspected as TVC and LV, respectively, and were subjected to histopathological examination. Mantoux test was found to be strongly positive (18 mm × 16 mm) with raised erythrocyte sedimentation rate of 60 mm/1st h. HIV serology by ELISA was negative. Histopathology from the left sole was consistent with TVC with marked hyperkeratosis and acanthosis with neutrophilic infiltration in the upper dermis and upper dermal ill-defined granuloma with Langhans giant cell [Figure 2]. The other lesion was consistent with LV with minimal acanthosis, hyperkeratosis, and caseating tubercle in upper dermis surrounded by lymphocyte and epithelioid cells [Figure 3]. Staining for acid-fast bacilli was found to be negative in both. The patient was started on antituberculous treatment (Category I) with isoniazid, rifampicin, ethambutol, and pyrazinamide.

Figure 1

Verrucous plaque of tuberculosis verrucosa cutis over the left sole and bilobed plaque of lupus vulgaris over the left forearm

Figure 2

Upper dermal ill-defined granuloma with Langhans giant cell (H and E, ×40)

Figure 3

Caseating tubercle in upper dermis surrounded by lymphocyte and epithelioid cells (H and E, ×40)

A 45-year-old lady, fishmonger by profession presented with a warty lesion over the left palm and an annular plaque over the right arm [Figure 4]. Palmer lesion appeared first and it was a verrucous plaque with deep fissures. The lesion over the right arm was an annular plaque with papulonodular lesions at the periphery with central atrophic scarring and healing at places. Margin of the lesion showed hypertrophy at some areas. A provisional diagnosis of TVC of the left palm and LV of the right arm was made. Mantoux test was found to be strongly positive and histopathology was consistent with clinical diagnosis.

Figure 4

Warty lesion with deep fissures over the left palm and an annular plaque with central atrophic scarring over the right arm

Although cutaneous TB is on the decline,[1] emergence of HIV infection has led to an increased incidence of extrapulmonary TB which may also be reflected in cutaneous TB in future. In this era of immune juggling, especially due to HIV and use of many immunosuppressive and immunomodulatory drugs, diagnosis of cutaneous TB often becomes a difficult task.

Coexistence of TVC and LV is not common, and there are only limited numbers of case reports showing such coexistence.[23] TVC had been found to be associated with other forms of cutaneous TB.[45] In conformity with the various studies regarding coexistence of different forms of cutaneous TB including the index cases, TVC developed at distant sites.

Our patients showed features of LV and TVC separately at the different sites of the body. Sitting or barefoot walking over infected sputum may result in TVC by direct inoculation[67] and this may be the mode of acquisition of TVC in the first case, whereas in the second case occupation of the lady justifies its occurrence over the palm. Later development of LV in both the cases may be either through hematogenous spread or through autoinoculation from TVC. Coexistence of two different forms of cutaneous TB is uncommon and should be kept in mind for the possibility.

Cutaneous TB usually manifests as a single clinical morphological form. However, two or more different morphological forms may coexist in the same patient. As the diagnostic aids are not always supportive, based on clinical suspicion antitubercular therapy can be instituted and which in turn may serve as a diagnostic criterion.

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Conflicts of interest

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