Case
17. (23 Feb. 1998)
Diagnosis: Squamous cell lung cancer (with
cystic lung to lung metastasis)
Squamous cell carcinoma is located most frequently in
a segmental or lobar bronchus. Frequently, the tumor invades the submucosal
and peribronchial connective tissue at the same time as it extends into
the airway lumen. Airway obstruction is almost invariable in this circumstance;
as a consequence, distal atelectasis and obstructive pneumonitis are present
to some degree in most cases at presentation. Central necrosis is frequent
and often extensive; drainage of necrotic material leads to cavitation
in many cases. Cavity formation can be categorized into three different
types: 1) central necrosis of the neoplasm, 2) a lung abscess distal to
an obstructing neoplasm. 3) cavitary abscesses elsewhere in the lungs,
presumably resulting from spill-over of purulent material from segmental
pneumonitis and abscess formation elsewhere. Most of these cavities are
thick-walled, resembling acute lung abscesses. The inner surface is usually
irregular as a result of variably sized nodules of neoplastic tissue projecting
into the cavity and of the patchy nature of the necrosis. Cavitation may
be central or eccentric, 1 to 10 cm in diameter, with walls 0.5 to 3.0
cm thick. Occasionally, the cavity walls can be extremely thin, simulating
a bulla or bronchial cyst.
Return to Case 17. (23 Feb.
1998)