Reportamos tres adultos, seronegativos para el virus de inmunodeficiencia humana (VIH), evaluados para descartar un proceso tumoral en el mediastino; que resultaron tener una linfadenopatía tuberculosa. Esta presentación de tuberculosis intratoráxica (en adultos) tiene una frecuencia baja especialmente cuando se acompaña de una radiografía standard del tórax normal: lo que dificulta su diagnóstico.

Revisamos la utilidad de las técnicas invasivas (punción aspiración transtorácica con aguja fina guiada por TAC o la toracotomía) para descartar un proceso neoplásico y reportamos una aplicación de la reacción en cadena de la polimerasa (PCR) para el diagnóstico específico de la tuberculosis en material de biopsia. La linfadenopatía tuberculosa mediastinal es sinónimo de infección primaria en los adultos y niños en zonas de baja prevalencia; pero en poblaciones con alta endemicidad como la nuestra, pudiese ser en los adultos la expresión de reactivación de la enfermedad durmiente, aún en presencia de una radiografía standard de tórax normal. Compartimos nuestra experiencia para inducir y mantener un alto índice de sospecha sobre esta posibilidad diagnóstica cuando se maneje pacientes con “masas mediastinales" en áreas de alta prevalencia como la nuestra.

Palabras Claves: Linfadenopatía tuberculosa, Mediastino, PCR, tuberculosis, tuberculosis Mediastinal, Tumores del Mediastino).

The preliminary report of the study of 43 patients with breast cancer studied by 99mTc sestamibi scintigraphy, is presented. Three groups of cases are included: Group 1) Ten patients before any therapeuti intervention, Group 2a) Twenty six cases studied by scintigraphy during the c1inical course of the disease after the initial surgical treatment, without clinical evidences of tumor activity, but with increased level of CA -15.3, and Group 2b) Seven patient studied during c1inica! course of disease but with evidences of local recurrence or distal metastases. 

In all cases sc intigraphies were done 10 minutes and l hour after 99m Tc-sestamibi e.v. administration, acquiring pictures of 1) Thorax (both breast and axiles , as well as mediastinum and both lung fields), and 2) Each breast or contralateral breast, according to the case, in tangential projection, with patient in lateral -prone -position. Normal sc intigraphies presents uniform distribution of the radioactive body background over breasts, axiles and thorax, with normal phisio logical uptak in the thyroid and sallivary glands , miocardium, liver and gallbladder, small bowel, and kidneys.

Abnormal scintigraphies shows " hot" areas in the We report three HIV negative adults referred for me diastinal tumor evaluation. Work -up revealed biopsy proven tuberculous limphadenitis. This is an infrequent presentation of intrathoracic tuberculosis (in adults) specially when associated with a normal chest x ray like our patients hado We reviewed the invasive diagnostic tech
niques (CT guided FNA and thoracotomy) and the value of PCR in biopsy material for tuberculous diagnosis . In
low prevalence areas a mediastinal tuberculous limpha denitis is equi valent to a primary infection both in pedia trie and adult populations; but in high prevalence areas Iike ours, it may represent arare form of tuberculous reactivation even in the presence of a normal chest x rayo We share our experience to induce and maintain a high index of suspicious of patients with this diagnostic possibility when taking care of "mediastinal masses " in areas of
high tuberculous prevalence like ours .
 

key Words: Tuberculous lymphadenopathy, Medias
tinum , PCR, tuberculosis, Mediastinal Tuberculosis, Me
diastinal Tumors).