604
Fig.2 CT scan of the chest demonstrates a low-density mass in the
right suprahilar region inseparable from the mediastinum. Note
the close proximity of the mass to a portion of the right upper
lobe bronchus ꢀarrow)
Fig.1 Frontal chest radiograph demonstrates a RUL pneumonia.
The right suprahilar mass is obscured by the lung disease
were perihilar in location, and at operation the left lung
mass was in close proximity to the lingular bronchus. It
has been postulated that, like parotid LEC that develop
in noninflammatory lymphoid tissue within the parotid
gland, or in intra- or paraparotid lymph nodes [7], intra-
thoracic LECs develop in peribronchial lymph nodes or
in noninflammatory peribronchial lymphatic tissue [6].
The development of the LEC in close proximity to the
apical segment of the RUL bronchus in our patient con-
tributed to recurrent post-obstructive pneumonia.
tion of the pneumonia following antibiotic therapy, the patient un-
derwent a thoracotomy. At surgery, 10 cm3 of turbid fluid was aspi-
rated from the extrapulmonary, juxtabronchial mass. Because the
mass was grossly adherent to the RUL pulmonary artery and pul-
monary vein and compressed the RUL bronchus, it was partially
excised and marsupialized. Pathology revealed lymphoid and fi-
brous tissue with respiratory and squamous epithelium in the cyst
wall consistent with a LEC. No inclusion bodies were identified.
Mandel and Hong [4] has proposed that parotid LEC
may develop within extraglandular infiltrative lymphoid
tissue. Our patient had no history of pulmonary lym-
phoid hyperplasia. However, given the association be-
Discussion
Lymphoepithelial cysts of the salivary glands, first de- tween parotid LEC and lymphoid infiltration of the
scribed in 1985 [2], have been well described in adults lung, the occurrence of intrathoracic LEC is not entirely
and children seropositive for human imunodeficiency surprising.
virus type 1[1].LECs occur most commonly in the pa-
The radiographic and histologic findings of intratho-
rotid gland, although they have also been described in racic LEC and parotid LEC are similar to those of
the submandibular gland, tonsils, thyroid gland and pan- HIV-related multilocular thymic cysts ꢀMLTC). MLTC
creas, and vary from simple cysts to complex cystic and have been described in HIV in both children and adults,
solid masses. They are considered benign reactive le- often in the setting of DILS [8, 9]. It is likely that intra-
sions [3]. LECs are often associated with diffuse lym- thoracic LEC, parotid LEC, and MLTC all represent
phocytosis syndrome, ꢀDILS) which is characterized by similar manifestations of DILS. Pathologically, they are
CD8 lymphocytosis, visceral CD8 lymphocytic infiltrate believed to result from cystic transformation of duct ep-
ꢀmost commonly of the lung), bilateral parotid swelling ithelial structures induced by the reactive lymphoid hy-
and cervical adenopathy [4]. Of note, our patient dem- perplasia accompanying HIV infection [8±10].
onstrated none of these signs. Pathologically, the cysts
In summary, although there are many more common
are characterized by lymphoid and epithelial cells as causes of lung masses in a HIV-positive child, including
well, as germinal centers in the cyst wall [4]. They may infection and neoplasm, the diagnosis of intrathoracic
serve as a reservoir of HIV particles [5].
LEC should be entertained if the child presents with
Intrathoracic LEC is an unusual entity and we could one or more central, cystic pulmonary masses adjacent
find only a single report of an intrathoracic LEC occur- to the tracheobronchial tree. If one extrapolates from
ring in a 35-year-old woman with HIV who presented the clinical experience with parotid LEC and MLTC
with bilateral lung masses [6]. As in our case, the masses ꢀboth of which have a benign course), it may be reason-
Leake
