56

with traditional ideas of histogenesis

of bronchopulmonary neoplasms appears no

longer tenable.

The "Grey Area" Between Small Cell and

Non-Small Cell Lung Carcinomas: Light and Electron Microscopy versus Clinical

Data in 14 Cases. Mooi, W.J., van Zandwijk, N., Dingemans, K.P., Wagenvoort, C.A. Academisch Medisch Centrum, Amsterdam, The Netherlands.

We studied 14 lung tumors which on light microscopy were difficult to classi-

fy as either small cell or non-small cell carcinomas. The light and electron micro- scopical features were compared to the clinical follow-up data.

Electron microscopy showed neuroendo- crine granules in 12 cases, and adeno- and squamous cell differentiation in the remaining 2 cases. The latter 2 cases showed prolonged patient survival (both alive after 23 and 2 years, respectively).

Ten of the cases with neuroendocrine granules showed a rapid course of disease (survival ranging fran 23 weeks to 15 months) and marked response to multiagent chemotherapy. Thus, the clinical impres- sion of these patients was that of small

cell carcinoma. The remaining 2 cases with neuroendo-

crine granules showed a more protracted course (survival 13 and 23 years). These 2 tumors did not show the light microsco- pic features of atypical carcinoid.

The results demonstrate the value of electron microscopy in classification of carcinomas difficult to place in small cell or non-small cell groups. They also point to the existence of neuroendocrine carcinomas other than carcinoids with a more protracted course than small cell

carcinomas.

Retrospective Histologic Reclassification of Long Term Sul~ivors with Small Cell

Carcinoma (SCC). Memoli, V.A., Maurer, L.H. Dartmouth Hitch- cock Medical Center, Hanover, ~H.

Long term survivors, defined as great- er than 2 years post diagnosis, represent a small percentage of the total group with SCC. A recent classification system for pulmonary neuroendocrine (NE) carcinomas (Lab Invest 49, 519, 1983) has described a tumor type designated as well-differen- tiated NE carcinoma (WNEC), with distinct histologic features and a clinical course than is far less aggressive than SCC. Pathology materials, including biopsies and cytologies were obtained from our files on 14 patients defined as long term survivors with a diagnosis of SCC. Their histology was reviewed and reclassi-

fied according to the new classification.

Ten cases (71.4%) were readily reclassified as WNEC. Six of these cases were patients who

were disease free for three or more years. The remaining four oatients in this group are ali- ve with recurrence and/or metastases at 2-3 years. Two cases were classified as SCC. and of these, one case has survived two years and the other, five years. Two cases were not read- ily classifiable with the available pathology material.

These results suggest that a majority of pa- tients who are long term survivors with SCC, demonstrate both clinical and pathologic fea- tures that justidy their separation from other patients with typical SCC.

DNA Distribution in Non Small Cell Lung Car- cinomas (NSCLC) Related to Prognosis. Volm, M., Drings, P., Mattern, J., Sonka, J. Vogt-Moykopf, I., Wayss, K. German Cancer Re- search Center, Chest Hospital Rohrbach, Hei- delberg, FRG.

The purpose of the study was to assess the clinical prognostic significance of DNA pat- terns in NSCLC.

Specimens of 187 tumors were investiga- ted by means of flow cytometry. Eighty-four percent of the tumors were classified as tumors with DNA-aneuploidy. Patients with tumors de- monstrating DNA aneuploidy had significantly shorter survival times than those with tumors demonstrating DNA-diploidy (p=0.009).

Cell cycle analysis was possible in i12 tumors. Patients whose tumors had a proportion of S-phase cells of 0-8% died later than pa- tients whose tumors had a proportion of S-pha- se cells of 9-16% (p=0.018). In addition, pa- tients with tumors with a low fraction of la-

beled S-phase cells (autoradiography) had a better prognosis than patients with tumors with a high proportion of labeled S-phase cells (p=0.041). Patients whose tumors showed a low Go/Gl-cell proportion died earlier (p= 0.03).

In conclusion, the analysis has Ehow~ that estimation of DNA content and distribution of stages of cell cycle using flow cytometry and autoradiography represent a useful tool for estimating prognosis of NSCLC-patients.

l~ntmohistochemical Study of Pulmonary Adeno- carcinoma. Kawai, T., Torikata I, C., Suzuki, M. Depart- ment of Pathology, National Defense Medical College, Tokorozawa. i. Department of Pathology, School of Medicine Keio University, Tokyo, Japan.

Well differentiated adenocarcinomas are subtyped electron microscopically into (A) bronchial surface epithelial. (B) goblet, (C) bronchial gland, (D) non-ciliated (Clara) and (E) type II alveolar cell types. In order to know the subtype and differentiation of pulmo- nary adenocarcinomas, 105 pulmonary adenocarci- nomas were immunohistochemically studied. Avidin- biotin peroxidase complex methods for determi-

ning keratin, vimentin, carcinoembryonic anti-