- Email: [email protected]
Necrotizing sialometaplasia involving the mucous glands of the nasal cavity
MEDICAL INTELLIGENCE events l e a d i n g to its p r o d u c t i o n is c o n s i d e r e d to be as follows: T h e e n d o m e t r i o s i s resulted in s m o o t h muscle h y p e r t r o p h y o f the a p p e n d i x , i n c l u d i n g the muscularis Inucosae, with obstruction o f s o m e o f the g l a n d crypts (Fig. 5). T h i s obstruction led to local i n c r e a s e d m u c i n p r o d u c t i o n with the p r o d u c t i o n o f m u l t i p l e small cysts. U h i m a t e l y coalescence o f these small cysts resulted in the single large one, which dissected t h r o u g h the s u b m u c o s a proximally (Figs. 1,2). E n d o m e t r i o s i s o f the a p p e n d i x is also a r a r e lesion. Most cases a r e associated with e n d o m e t r i o s i s in o t h e r pelvic a n d a b d o m i n a l structures. U o h a r a a n d K o b a r a ~a r e p o r t e d a 0.8 p e r cent i n c i d e n c e o f a p p e n d i c e a l e n d o metriosis in a p p r o x i m a t e l y 1500 a p p e n d e c tomies. T h i s figure m a y be artificially high, h o w e v e r , since the s u r g e r y was p e r f o r m e d in a hospital specializing in obstetrics a n d gynecology. Eight o f their 12 patients had e n d o metriosis d e m o n s t r a t e d elsewhere, usually in the ovaries. T h e f r e q u e n c y o f s y m p t o m a t o l o g y d u e to a p p e n d i c e a l e n d o m e t r i o s i s is a controversial m a t t e r in the literature, a n d is complicated by c o n f u s i o n with s y m p t o m s f r o m extraa p p e n d i c e a l endometriosis. T h e a p p e n d i x in t h e case u n d e r discussion was evidently asymptomatic. T w o r e p o r t s w e r e f o u n d that related appendiceal mucocele to endometriosis. 3 h e m i l t ~4 r e p o r t e d a m u c o c e l e that h e believed ,~as s e c o n d a r y to obstruction at the base o f the a p p e n d i x by fibrosis a n d e n d o m e t r i o s i s o f the cecnm. U n f o r t u n a t e l y his illustrations w e r e s o m e w h a t difficult to interpret. In his F i g u r e 170 he s h o w e d what was said to be t h e wall o f the c e c u m , at the base o f the a p p e n d i x , with two areas o f e n d o m e t r i o s i s within it. T h e l a r g e r o f the two glands was d e s c r i b e d as showing e n d o c e r v i c a l metaplasia, w h e r e a s the snmller was t h o u g h t to be typical e n d o m e t r i o s i s . T h e smaller g l a n d is acceptable as e n d o metriosis, for it s h o w e d what a p p e a r e d to be a small a m o u n t o f s t r o m a s u r r o u n d i n g it. However, the large g l a n d a p p e a r e d to us to be a colonic gland with changes consistent with hyperplasia o r neoplasia, as in a m u c i n o u s cystadenoma. It w o u l d seem, o n balance, that this m u c o c e l e may be related both to e n d o metriosis a n d to p r i m a r y mucosal alteration o f the cecum. Hilsabeck et al., 6 in s t u d y i n g a s~ries o f unusual mucoceles, m e n t i o n e d two cases associated with e n d o m e t r i o s i s . T h e y w e r e unable, h o w e v e r , to p r o v e that t h e e n d o m e triosis was pathogenetically i m p o r t a n t . T h u s , the p r e s e n t case a p p e a r s to us to be the only well d o c u m e n t e d e x a m p l e o f an obstructive m u c o c e l e s e c o n d a r y to e n d o m e t r i o s i s o f the a p p e n d i x . F u r t h e r m o r e , this m u c o c e l e
a p p e a r s to be p u r e l y obstrnctive a n d u n r e lated to any p r i m a r y mucosal a b n o r m a l i t y o f the a p p e n d i x .
References 1. Warren, S., and Warren, A. S.: A stud)' of 6797 surgically removed appendices. Ann. Surg., 83:222, 1926. 2. Woodruff, R., and McDonald,J. R.: Benign and malignant cystic tumors of the appendix. Surg. Gynecol. Obstet., 71:750, 19t0. 3. Aschoff, 1..: Appendicitis. Its Aeteriology and I'athology. (Translated by G. G. Pather.) London, Constable & Co., Ltd., 1932. 4. Fraeukel, E.: Ueber das sogennante pseudomyxoma peritonei. Munchen. Med. Wschr., 48:965, 1901. 5. ttiga, E., Rosai, J., Pizzimbono, C. A., and Wise, L.: Mucosal hyperplasia, mucinous cystadenoma, and mutinous cystadenocarcinoma of the appendix. A re-evaluation of appendiceal "'mucocele." Cancer, 32: 1525, 1973. 6. Hilsabeck, J. R., Woolner, I.. B., and Judd. E. S.: Some uncommon causes of appendiceal mucocele. Am. J. Surg.. 84:670. 1952. 7. Naesltmd, J.: Upsala Laekeref. Foerh., 34:1, 1928. (Quoted in Cheng, K. K., op. cit., and in Woodruff, R., and McDonald,J. R.,op. cit.). 8. Wells, A. Q.: Experimental lesions of the rabbit's appendix. Brit.J. Surg.,24:766, 1937. 9. Cheng, K. K.: An experimental stud)" of nmcocele of the appendix and pseudomyxoma peritonei. J. Pathol. Bacteriol., 61:217, 1949. 10. Woolner, L. B.: Carcinoma of the appendix. Comments on pathology. Proc. Staff Meet..Mayo Clin:, 28:17, 1953. 11. Qizilbasb, A. H.: Mucoceles of the appendix. Arch. Pathol., 99:548, 1975. 12. Wangensteen, O., and Dennis, C.: Experimental proof of the obstructive origin of appendicitis in man. Ann. Surg., 110:629, 1939. 13. Uohara, J. K., and Kobara, T. Y.: Endometriosis of the appendix. Amer. J. Obstet. Gynecol., 121~423, 1975. 14. Shemilt, P.: Endometrioma of the caecum causing muc~ cele of the appendix. Brit. J. Surg., 37:118, 1949.
NECROTIZlNG SlALOMETAPLASIA INVOLVING THE MUCOUS GLANDS OF THE NASAL CAVITY WILLIAM H. JOHNSTOX, M.D.*
Abstract
Necrotizing sialometaplasia was found in maxillary sitars mucous glamls of an 83 year old woman who had undergone a radical maxillectomy f o r basal cell carcinoma 10 days earlier. Previously recognized as an ulcerating lesion involving salivaly glands in the oral cavity, this ben~n reactive *Assistant Professor, Department of l'athology, School of Medicine, University of California, l.os Angeles, California.
589
H U M A N P A T H O L O G Y - - V O L U M E 8, N U M B E R 5 process may also occur in the mucous glands of the nasal cav#y and simtses mtd can simulate squamous cell or mucoepidermoid carcinoma. Ischemia appears to be pathogenetic. Necrotizing sialometaplasia is a recently described benign condition o f salivary glands tlmt may be confused histologically with squamous cell or m u c o e p i d e r m o i d c a r c i n o m a ) a Fourteen cases have been described in the oral cavity as ulcerating lesions o f the palate. Mucous glands o f the nasal cavity and accessory sinuses may also show this change, and two cases are concurrently being r e p o r t e d in a clinical j o u r n a l : T h e p u r p o s e o f this r e p o r t is to present a third case involving nlucous glands o f the maxillary sinus mucosa in o r d e r to alert pathologists to the occurrence o f necrotizing sia[ometapIasia in this location. Tim histologic findings are typical in all respects. CASE R E P O R T An 83 }'ear old Caucasian woman entered the University o f California, Los Angeles, Center for the Health Sciences with a four )'ear history o f an ulcerative, deeply penetrat-
590
S@tember 1977
ing basal cell carcinoma o f the skin o f the right cheek. Tiffs neoplasm had been treated unsuccessfully by excision and local irradiation. A right radical maxillectomy including orbital exenteration was performed. B e c a u s e basal cell carcinoma e x t e n d e d to several surgical margins o f resection, additional tissue was excised at the time o f plastic reconstruction 10 days later. Residtml basal cell carcinoma was not identified, but necrotizing sialometaplasia was evident in several mucous glands o f the right maxillary sinus mucosa (to be described). PATHOLOGIC FINDINGS T h e maxillary sinus specimen excised in tim second operation consisted o f a single piece of bone and overlying tan mucosa measuring 2.5 by 1.0 by 0.6 cm. Tim mucosal surface was granular. Microscopically the sinus epithelium showed squamous metaplasia and ulceration over mucous gland lobules, the outlines o f which were well preserved (Fig. 1). An inflammatory exudate containing p o l y m o r p h o n u clear leukocytes and m o n o n u c l e a r cells ext e n d e d from the ulcer base into the underlying fibrous stroma, a r o u n d and witlfin the mucous
Figure 1. An ulcerated mucosal surface overlies a partially necrotic mucous gland at tile lower right, the Iobular configuration of which remains intact..Metal)lastic stratified sqvanmus epitheliun~ fills some mucous gland ducts and acini and adjoins the zone of surface ulceration at the upper left. (ttematoxylin aqd eosin stain.
MEDICAL INTELLIGENCE
Figure 2. Mucous gland ducts and acini at the right are partially or completely filled with metal)lastic str,'itified squamous epithelium. A few uninvoh'ed gland elements nre present at the left. The stroma contains mHnerous l)olymorphonuclear leukocytes and mononuclear intlammatory cells. Near the upper right corner is a thronlbus, which distends and occludes a blood vessel. A few fibroblasts infiltrate the thrombus peril)herally. (Hematoxylin and eosin stain, x170.)
glands. Within the lobules, tile mucous gland ducts and acini showed extensive squamous metaplasia and infihration by polymorpllonuclear leukocytes and m o n o n u c l e a r cells (Fig. 2). A recent thrombus filled and occluded a blood vessel within one o f the affected nlucous glands (Fig. 2), and ingrowth o f a few fibroblasts was evident peripherally. Ductal lumens frequently contained necrotic debris and polym o r p l l o n u c l e a r leukocytes, a n d tile lining epithelium o f some ducts was necrotic adjoining areas o f squamous metaplasia. Adjacent to areas o f necrosis, r e g e n e r a t i n g epitheliuna frequently contained mitotic figures and enlarged nuclei with p r o m i n e n t nucleoli. Such epithelium occasionally contained scattered, individually necrotic ceils with pyknotic, sometimes karyorrhectic nuclei and condensed eosinophilic cytoplasm. Extraglandular mucus was sometimes present in the stroma. All metaplastic epitllelium lay within the confines o f the mucous gland lobules, and tile pattern o f metaplasia within the lobules a p p e a r e d infiltrative only when viewed in isolation. Decalcified sections o f the u n d e r l y i n g bone revealed u n r e m a r k a b l e microscopic features.
DISCUSSION
Necrotizing sialometaplasia has tile same histologic a p p e a r a n c e in mucous glands o f the nasal cavity a n d accessory sinnses as in salivary glands. Criteria for diagnosis as first defined by Abrams and associates I are as follows: lobu[ar infarction o r partial necrosis with maintenance o f tile general lobular architecture, sqnanlous metaplasia of affected ducts and acini, cytologically benign nuclear morphology o f the metaplastic sqt, amous cells, and p r o m i n e n t acute and chronic inflanmmtion in and a r o u n d the involved glands. Active regeneration and metaplasia o f el~ithelium in areas o f necrosis may be associated with nuclear enlargement, p r o m i n e n t nucleoli, fi'eqttent mitotic figures, and necrosis o f cells individuall)" o r in small groups. Such changes must be taken in tile context o f the overall appearax~ce o f the specimen for p r o p e r interpretation. Small biopsy specimens, which might include only the necrotic and actively regenerating porions o f the lesion, could obviously cause diagnostic problems. Ischemia a p p e a r s to be responsible for tile necrotic and reactive changes in necrotizing sialometaplasia. In tiffs case the blood supply o f
591
HUMAN
PATHOLOGY--VOLUME
8, N U M B E R 5
the affected mt,cous glands may have b e e n imp a i r e d by vascular c l a m p i n g and s u t u r e p l a c e m e n t at m a x i l l e c t o m y I0 days earlier. An o r g a n i z i n g t h r o m b u s within a blood vessel in o n e o f the a b n o r m a l glands probably f o r m e d following s u r g e r y a n d must have f l l r t h e r c o m p r o m i s e d the b l o o d supply. T h e changes o f n e c r o t i z i n g sialometaplasia o c c u r r e d rapidly, a p p e a r i n g 10 days a f t e r the radical nmxillectomy. T h e acute i n f l a m n m t i o n , o n g o i n g necrosis, and mitotic activity in the metaplastic stratified s q u a m o u s e p i t h e l i u m c o r r e l a t e with tiffs interval. T h e m o r e r e m o t e t h e r a p e u t i c p r o c e d u r e s probably b e a r no relationship in Otis case. T h e p r e v i o u s s u r g e r y was not in the r e g i o n o f the maxillary sinus, and t h e r e w e r e no vascular o r stronml changes to suggest a radiation reaction. T h u s , n e c r o t i z i n g sialometaplasia may
592
September 1977
o c c u r in tile m u c o u s glands o f the nasal cavity a n d sinuses as well as in m i n o r salivary glands in the oral cavity. Ischemia a p p e a r s to cause the b e n i g n necrotic a n d reactive changes. References
I. Abrams, A. M., .Melrose, R.J., and tlowell, F. V.: Neerotiziog sialometaplasia. A disease simulating malignancy.. Cancer,32:130,197.3. 2. Dunlap, C. L., and Barker, B. F.: Necrotizing sialometaplasia. Report of five additional eases. Oral Surg., 37: 722, 1974. 3. Myers, E. N., Bankaci, M., and Barnes, E. L.: Neerotizing sialometaplasia. Report of a case. Arch. Otolar)ngol.. 101:628, 1975. 4. Willis, I'. l., and Fechner, R. E.: Pathologic quiz case 1. Arch. Otolaryngol., 101:76, 1975. 5. Malsel, R. tl., Johnston, W. It., Anderson, II. A., and Cantrell, R. W.: Necrotizing sialometaplasia involving the nasal cavity. Report of 2 cases. Laryngoscope, 87: 429, 1977.
a p p e a r s to be p u r e l y obstrnctive a n d u n r e lated to any p r i m a r y mucosal a b n o r m a l i t y o f the a p p e n d i x .
References 1. Warren, S., and Warren, A. S.: A stud)' of 6797 surgically removed appendices. Ann. Surg., 83:222, 1926. 2. Woodruff, R., and McDonald,J. R.: Benign and malignant cystic tumors of the appendix. Surg. Gynecol. Obstet., 71:750, 19t0. 3. Aschoff, 1..: Appendicitis. Its Aeteriology and I'athology. (Translated by G. G. Pather.) London, Constable & Co., Ltd., 1932. 4. Fraeukel, E.: Ueber das sogennante pseudomyxoma peritonei. Munchen. Med. Wschr., 48:965, 1901. 5. ttiga, E., Rosai, J., Pizzimbono, C. A., and Wise, L.: Mucosal hyperplasia, mucinous cystadenoma, and mutinous cystadenocarcinoma of the appendix. A re-evaluation of appendiceal "'mucocele." Cancer, 32: 1525, 1973. 6. Hilsabeck, J. R., Woolner, I.. B., and Judd. E. S.: Some uncommon causes of appendiceal mucocele. Am. J. Surg.. 84:670. 1952. 7. Naesltmd, J.: Upsala Laekeref. Foerh., 34:1, 1928. (Quoted in Cheng, K. K., op. cit., and in Woodruff, R., and McDonald,J. R.,op. cit.). 8. Wells, A. Q.: Experimental lesions of the rabbit's appendix. Brit.J. Surg.,24:766, 1937. 9. Cheng, K. K.: An experimental stud)" of nmcocele of the appendix and pseudomyxoma peritonei. J. Pathol. Bacteriol., 61:217, 1949. 10. Woolner, L. B.: Carcinoma of the appendix. Comments on pathology. Proc. Staff Meet..Mayo Clin:, 28:17, 1953. 11. Qizilbasb, A. H.: Mucoceles of the appendix. Arch. Pathol., 99:548, 1975. 12. Wangensteen, O., and Dennis, C.: Experimental proof of the obstructive origin of appendicitis in man. Ann. Surg., 110:629, 1939. 13. Uohara, J. K., and Kobara, T. Y.: Endometriosis of the appendix. Amer. J. Obstet. Gynecol., 121~423, 1975. 14. Shemilt, P.: Endometrioma of the caecum causing muc~ cele of the appendix. Brit. J. Surg., 37:118, 1949.
NECROTIZlNG SlALOMETAPLASIA INVOLVING THE MUCOUS GLANDS OF THE NASAL CAVITY WILLIAM H. JOHNSTOX, M.D.*
Abstract
Necrotizing sialometaplasia was found in maxillary sitars mucous glamls of an 83 year old woman who had undergone a radical maxillectomy f o r basal cell carcinoma 10 days earlier. Previously recognized as an ulcerating lesion involving salivaly glands in the oral cavity, this ben~n reactive *Assistant Professor, Department of l'athology, School of Medicine, University of California, l.os Angeles, California.
589
H U M A N P A T H O L O G Y - - V O L U M E 8, N U M B E R 5 process may also occur in the mucous glands of the nasal cav#y and simtses mtd can simulate squamous cell or mucoepidermoid carcinoma. Ischemia appears to be pathogenetic. Necrotizing sialometaplasia is a recently described benign condition o f salivary glands tlmt may be confused histologically with squamous cell or m u c o e p i d e r m o i d c a r c i n o m a ) a Fourteen cases have been described in the oral cavity as ulcerating lesions o f the palate. Mucous glands o f the nasal cavity and accessory sinuses may also show this change, and two cases are concurrently being r e p o r t e d in a clinical j o u r n a l : T h e p u r p o s e o f this r e p o r t is to present a third case involving nlucous glands o f the maxillary sinus mucosa in o r d e r to alert pathologists to the occurrence o f necrotizing sia[ometapIasia in this location. Tim histologic findings are typical in all respects. CASE R E P O R T An 83 }'ear old Caucasian woman entered the University o f California, Los Angeles, Center for the Health Sciences with a four )'ear history o f an ulcerative, deeply penetrat-
590
S@tember 1977
ing basal cell carcinoma o f the skin o f the right cheek. Tiffs neoplasm had been treated unsuccessfully by excision and local irradiation. A right radical maxillectomy including orbital exenteration was performed. B e c a u s e basal cell carcinoma e x t e n d e d to several surgical margins o f resection, additional tissue was excised at the time o f plastic reconstruction 10 days later. Residtml basal cell carcinoma was not identified, but necrotizing sialometaplasia was evident in several mucous glands o f the right maxillary sinus mucosa (to be described). PATHOLOGIC FINDINGS T h e maxillary sinus specimen excised in tim second operation consisted o f a single piece of bone and overlying tan mucosa measuring 2.5 by 1.0 by 0.6 cm. Tim mucosal surface was granular. Microscopically the sinus epithelium showed squamous metaplasia and ulceration over mucous gland lobules, the outlines o f which were well preserved (Fig. 1). An inflammatory exudate containing p o l y m o r p h o n u clear leukocytes and m o n o n u c l e a r cells ext e n d e d from the ulcer base into the underlying fibrous stroma, a r o u n d and witlfin the mucous
Figure 1. An ulcerated mucosal surface overlies a partially necrotic mucous gland at tile lower right, the Iobular configuration of which remains intact..Metal)lastic stratified sqvanmus epitheliun~ fills some mucous gland ducts and acini and adjoins the zone of surface ulceration at the upper left. (ttematoxylin aqd eosin stain.
MEDICAL INTELLIGENCE
Figure 2. Mucous gland ducts and acini at the right are partially or completely filled with metal)lastic str,'itified squamous epithelium. A few uninvoh'ed gland elements nre present at the left. The stroma contains mHnerous l)olymorphonuclear leukocytes and mononuclear intlammatory cells. Near the upper right corner is a thronlbus, which distends and occludes a blood vessel. A few fibroblasts infiltrate the thrombus peril)herally. (Hematoxylin and eosin stain, x170.)
glands. Within the lobules, tile mucous gland ducts and acini showed extensive squamous metaplasia and infihration by polymorpllonuclear leukocytes and m o n o n u c l e a r cells (Fig. 2). A recent thrombus filled and occluded a blood vessel within one o f the affected nlucous glands (Fig. 2), and ingrowth o f a few fibroblasts was evident peripherally. Ductal lumens frequently contained necrotic debris and polym o r p l l o n u c l e a r leukocytes, a n d tile lining epithelium o f some ducts was necrotic adjoining areas o f squamous metaplasia. Adjacent to areas o f necrosis, r e g e n e r a t i n g epitheliuna frequently contained mitotic figures and enlarged nuclei with p r o m i n e n t nucleoli. Such epithelium occasionally contained scattered, individually necrotic ceils with pyknotic, sometimes karyorrhectic nuclei and condensed eosinophilic cytoplasm. Extraglandular mucus was sometimes present in the stroma. All metaplastic epitllelium lay within the confines o f the mucous gland lobules, and tile pattern o f metaplasia within the lobules a p p e a r e d infiltrative only when viewed in isolation. Decalcified sections o f the u n d e r l y i n g bone revealed u n r e m a r k a b l e microscopic features.
DISCUSSION
Necrotizing sialometaplasia has tile same histologic a p p e a r a n c e in mucous glands o f the nasal cavity a n d accessory sinnses as in salivary glands. Criteria for diagnosis as first defined by Abrams and associates I are as follows: lobu[ar infarction o r partial necrosis with maintenance o f tile general lobular architecture, sqnanlous metaplasia of affected ducts and acini, cytologically benign nuclear morphology o f the metaplastic sqt, amous cells, and p r o m i n e n t acute and chronic inflanmmtion in and a r o u n d the involved glands. Active regeneration and metaplasia o f el~ithelium in areas o f necrosis may be associated with nuclear enlargement, p r o m i n e n t nucleoli, fi'eqttent mitotic figures, and necrosis o f cells individuall)" o r in small groups. Such changes must be taken in tile context o f the overall appearax~ce o f the specimen for p r o p e r interpretation. Small biopsy specimens, which might include only the necrotic and actively regenerating porions o f the lesion, could obviously cause diagnostic problems. Ischemia a p p e a r s to be responsible for tile necrotic and reactive changes in necrotizing sialometaplasia. In tiffs case the blood supply o f
591
HUMAN
PATHOLOGY--VOLUME
8, N U M B E R 5
the affected mt,cous glands may have b e e n imp a i r e d by vascular c l a m p i n g and s u t u r e p l a c e m e n t at m a x i l l e c t o m y I0 days earlier. An o r g a n i z i n g t h r o m b u s within a blood vessel in o n e o f the a b n o r m a l glands probably f o r m e d following s u r g e r y a n d must have f l l r t h e r c o m p r o m i s e d the b l o o d supply. T h e changes o f n e c r o t i z i n g sialometaplasia o c c u r r e d rapidly, a p p e a r i n g 10 days a f t e r the radical nmxillectomy. T h e acute i n f l a m n m t i o n , o n g o i n g necrosis, and mitotic activity in the metaplastic stratified s q u a m o u s e p i t h e l i u m c o r r e l a t e with tiffs interval. T h e m o r e r e m o t e t h e r a p e u t i c p r o c e d u r e s probably b e a r no relationship in Otis case. T h e p r e v i o u s s u r g e r y was not in the r e g i o n o f the maxillary sinus, and t h e r e w e r e no vascular o r stronml changes to suggest a radiation reaction. T h u s , n e c r o t i z i n g sialometaplasia may
592
September 1977
o c c u r in tile m u c o u s glands o f the nasal cavity a n d sinuses as well as in m i n o r salivary glands in the oral cavity. Ischemia a p p e a r s to cause the b e n i g n necrotic a n d reactive changes. References
I. Abrams, A. M., .Melrose, R.J., and tlowell, F. V.: Neerotiziog sialometaplasia. A disease simulating malignancy.. Cancer,32:130,197.3. 2. Dunlap, C. L., and Barker, B. F.: Necrotizing sialometaplasia. Report of five additional eases. Oral Surg., 37: 722, 1974. 3. Myers, E. N., Bankaci, M., and Barnes, E. L.: Neerotizing sialometaplasia. Report of a case. Arch. Otolar)ngol.. 101:628, 1975. 4. Willis, I'. l., and Fechner, R. E.: Pathologic quiz case 1. Arch. Otolaryngol., 101:76, 1975. 5. Malsel, R. tl., Johnston, W. It., Anderson, II. A., and Cantrell, R. W.: Necrotizing sialometaplasia involving the nasal cavity. Report of 2 cases. Laryngoscope, 87: 429, 1977.