Carcinoembryonic antigen and milk-fat globule protein staining of malignant mesothelioma and adenocarcinoma of the lung

139 b e t w e e n the two tumour types, especially in their m o r p h o l o g y and S-100 protein immunoreactivity, indicates that b r o n c h i a l carcinoids, or at least some of them, are histogenetically closely related to p h a e o c h r o m o c y t o m a s and m i g h t d e r i v e from the p e r i p h e r a l nervous system. Atypical E n d o c r i n e Tumors of the Lung: A Histologic, Ultrastructural, and C l i n i c a l S t u d y of 19 Cases. Havens Neal, M., Kosinski, R., Cohen, P., Orenstein, J.M. Department of Pathology, George W a s h i n g t o n U n i v e r s i t y M e d i c a l Center, Washington, DC 20037, U.S.A. Hum. Pathol. 17: 1264-1277, 1986. Lung cancers are d i v i d e d by light microscopic criteria into several categories, but only two c a t e g o r i e s are recognized c l i n i c a l l y - small cell and n o n - s m a l l cell carcinomas. T r a n s m i s s i o n e l e c t r o n m i c r o s c o p y has r e v e a l e d unexp e c t e d c o m p l e x i t y w i t h i n each category, b l u r r i n g the d i s t i n c t i o n s b e t w e e n them. The present study was u n d e r t a k e n to d e t e r m i n e the i n c i d e n c e of dense-core, neuroendocrine-type granules in lung tumors d i a g n o s e d by light m i c r o s c o p y as n o n - s m a l l cell carcinomas, i.e., atypical e n d o c r i n e tumors, and the c l i n i c a l significance of their identification. Of 205 c o n s e c u t i v e p r i m a r y and metastatic lung cancers, 19 (9 per cent) d i a g n o s e d as n o n - s m a l l cell carcinomas by light m i c r o s c o p y were seen to contain neuroendocrine-type granules by electron microscopy and thus were reclassified as atypical endocrine tumors of the lung. S t a i n i n g w i t h silver stains, p e r i o d i c a c i d - S c h i f f (PAS), PAS with diastase digestion, and m u c i c a r m i n e was p o s i t i v e in 18, 15, 14, and eight of the 19 cases, respectively. Electron microscopy revealed glandular d i f f e r e n t i a t i o n in 12 cases and tonofilaments in eight cases, althoug none of the tumors met the criteria for identification as squamous cell carcinomas. Clinically, the c a n c e r s a p p e a r e d to resemble nonsmall cell c a r c i n o m a more c l o s e l y than small cell c~:cinoma. Median survival (12 months) and response to c o m b i n a t i o n chemotherapy (22 per cent) were in the range reported for non-small cell carcinoma. There were no c o m p l e t e responses, despite the use in some cases of regimens active against small cell carcinoma. However, one patient, the only one to date so treated, had a d r a m a t i c r e s p o n s e to streptozotocin/5fluorouracil, suggesting that, as in m e t a s t a t i c carcinoid, this c o m b i n a t i o n may have value in the treatment of a t y p i c a l e n d o c r i n e tumors of the lung. Carcinoembryonic Antigen and M i l k - F a t Globule Protein S t a i n i n g of M a l i g n a n t

M e s o t h e l i o m a and A d e n o c a r c i n o m a of the Lung. Tron, V., Wright, J.L., Churg, A. D e p a r t m e n t of Pathology, U n i v e r s i t y of British Columbia, Vancouver, BC, Canada. Arch. Pathol. Lab. Med. iii: 291-293, 1987. Immunohistologic m a r k e r s have been of c o n s i d e r a b l e value in d i f f e r e n t i a t ing ° malignant mesothelioma from adenocarcinoma. Recently, s t a i n i n g for m i l k - f a t globule (MFG) p r o t e i n has been suggested as a useful d i a g n o s t i c test for this separation, but subsequent reports have been conflicting, with some authors finding clearcut differences, while others showed similar m a r k i n g of both tumor types. To examine this technique further, we studied lung carcinomas and mesotheliomas with commercially available anti-MFG, and compared these results with those obtained with anticarcinoembryonic antigen (CEA), a commonly used immunomarker of carcinoma. We found that carcinomas showed strong c y t o p l a s m i c staining for MFG and CEA; however, a greater percentage of carcinomas were more s t r o n g l y p o s i t i v e for CEA than for MFG. Mesotheliomas did not, for the most part, stain strongly with either antibody. In addition, carcinomas from d i f f e r e n t h o s p i t a l s stained d i f f e r e n t l y for MFG. but not for CEA. We conclude that a l t h o u g h strong c y t o p l a s m i c staining for MFG is a reasonable reliable indicator of carcinoma, CEA staining provides a better separation and is considerable easier to interpret in lung cancer specimens. 5. C L I N I C A L A S S E S S M E N T Abdominal CT in the Staging of SmallCell C a r c i n o m a of the Lung: Incidence of M e t a s t a s e s and Effect on Prognosis. Mirvis, S.E., Whitley, N.O., Aisner, J. et al. Department of Diagnostic Radiology, U n i v e r s i t y of M a r y l a n d Medical System, Baltimore, MD 21201, U.S.A. Am. J. Roentegnol. 148: 845-847, 1987. CT studies of the abdomen p e r f o r m e d on 72 patients with small-cell carcinoma of the lung were r e t r o s p e c t i v e l y reviewed to assess the role of abdominal CT in staging. Forty-four of the 72 p a t i e n t s had extensive disease, d e f i n e d as disease e x t e n d i n g beyond the confines of one hemithorax, plus or minus mediastinal or ipsilateral s u p r a c l a v i c u l a r disease or ipsilateral pleural effusion. I n i t i a l - s t a g i n g abdominal CT r e v e a l e d one or more sites of m e t a s t a t i c disease in 26 (59%) of these 44 patients, while 18 patients had normal initial CT examinations. S t a t i s t i c a l analysis of patients with extensive disease revealed a significant increase in complete