Histologic changes in small cell lung carcinoma after treatment.
BACKGROUND
Small cell lung carcinoma (SCLC) has been divided into three subtypes: pure SCLC, mixed small cell/large cell carcinoma (mixed SC/LC), and combined SCLC. Patients with mixed SC/LC show a worse prognosis than those with pure SCLC.


METHODS
Persistence of histologic subtype in SCLC in the primary sites during the course of treatment or in the different organs at autopsy was examined. For this purpose, biopsy or cytologic specimens before chemotherapy, and autopsy specimens from 175 patients with SCLC were reviewed. They included 147 (84%) men and 28 (16%) women with an age range of 29-83 (median, 65) years.


RESULTS
The frequency of mixed SC/LC in the primary sites was statistically higher in autopsy (14.3%) than that in biopsy or cytology specimens (8.6%) (P < 0.05). At autopsy, involved organs were categorized into two groups according to frequency of appearance of mixed SC/LC, i.e., a higher frequency group, including the liver (31 of 85; 36.4%), adrenal gland (15 of 56; 26.8%), brain (6 of 9; 66.7%), and extrathoracic lymph nodes (17 of 59; 28.8%) and a lower frequency group, including the lung (metastatic sites) (12 of 102; 11.8%), pleura (8 of 74; 10.8%), and intrathoracic lymph nodes (12 of 94; 12.8%). The difference in frequency between these two groups was statistically significant (P < 0.05).


CONCLUSIONS
These findings suggest that primary pure SCLC can progress to mixed SC/LC with an increased potential for distant metastasis.
Fushimi
H
H
Department of Pathology, Osaka Prefectural General Hospital, Japan.
Kikui
M
M
Morino
H
H
Yamamoto
S
S
Tateishi
R
R
Wada
A
A
Aozasa
K
K
Kotoh
K
K
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001344:Autopsy; D001706:Biopsy; D018287:Carcinoma, Large Cell / Q000188:drug therapy / Q000473:pathology*; D018288:Carcinoma, Small Cell / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis; D016019:Survival Analysis; D013997:Time Factors
D000970:Antineoplastic Agents