Pathology of cutaneous tuberculosis.

Cutaneous tuberculosis is caused by infection for Mycobacterium tuberculosis. There have been several methods to classify the infection. Traditionally, the infection has been divided into primary infection, where there has been no previous exposure to organismand secondary tuberculosis, resulting from reinfection.

Histology of cutaneous tuberculosis

Primary inoculation with tubercle bacilli it can start with the surface ulceration, epidermal hyperplasia and a dense dermal infiltrate rich in neutrophils (Figure 1). Disseminated cutaneous tuberculosis and orificial tuberculosis will typically show a similar neutrophilic reaction in early injuries. Over time, neutrophils are replaced by chronic inflammatory cells and necrotizers granulomatous inflammation surrounded by numerous lymphocytes whether the patient has a competent immune system (as seen with the clinical subtype vurrucosa tuberculosis). Figures 2,3,4 show the same image of the characteristic necrotizing granulomatous inflammation surrounded by a lymphocytic response to progressively higher increases. Tuber organisms are generally easy to find at first suppurative lesions and difficult to identify when granulomatous inflammation has developed well.

Lupus vulgaris is the most common clinical type of cutaneous tuberculosis reinfection and shows good formation. granulomas surrounded by chronic inflammatory cells, and central necrosis (Figures 2-4). Necrosis is usually less pronounced than the example illustrated here.

The scrofuloderma will show a histological image similar to that seen in Figures-2,4, but there is often superficial ulceration and suppuration, as well as infection. lymph nodes connect through breast Tracts with overlying skin.

Special studies for cutaneous tuberculosis.

Los organismos se pueden demostrar en la tuberculosis cutánea con Ziehl-Neelen / tinción ácido-rápida, pero pueden ser extremadamente difíciles de encontrar y ausentes en muchos casos, particularmente cuando la respuesta granulomatosa está bien establecida. Culture Studies are sometimes helpful, but can take months to complete. Polymerase chain reaction (PCR) may allow rapid analysis, but may not be very sensitive in paucibacillary forms of cutaneous tuberculosis.

Differential diagnosis of cutaneous tuberculosis pathology

Granulomatous syphilis, deep fungal infection, leishmaniasis - PCR and culture studies may be necessary for the distinction in difficult cases.

Tuberculoid Leprosy - Neural infiltration and less necrosis are clues to this diagnosis. Plasma Cells are said to be more common in leprosy. PCR or culture studies may be necessary for this distinction.

Sarcoidosis: generally lacks caseante necrosis but it can show something fibrinoid Degeneration within the granulomas that can cause confusion. The sarcoid generally lacks the lymphocytic response that is often seen in tuberculosis (Figures 1, 2). PCR and culture studies can be helpful.