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“Melanogenic metaplasia” of mucous glands
"MELANOGENIC METAPLASIA" OF MUCOUS GLANDS W. DONALD MACLENNAN, F.D.S., L.R.C.P., L.R.C.S., L.R.F.P. and S.(Edin. and Glas.)
Maxillo-Facial and Plastic Surgery Unit, Bangour General Hospital and A. A. SHrVAS, M.D., D.P.H.
Department of Pathology, University of Edinburgh MALIGNANT Melanoma o f the m o u t h is, of itself, a relatively u n c o m m o n lesion, particularly when the mucosa of the lower alveolus is involved. (Duckworth, I962). T h e case reported is considered to be of especial interest, because of the unique incidental findings as indicated in the title. T h e presence o f mucous glands in the resected specimen which were seen to be actively participating in the widespread 'junctional change' affecting the superficial squamous epithelium, necessitates a critical reappraisal of the current views regarding the histogenesis of melanomata. CASE R E P O R T
History. Man, aged 56, Master Plumber. Referred on 23rd August, z96I as an out-patient at Edinburgh Dental Hospital because of 'bad taste' in mouth, believed to be associated with purple lesion in right alveolar region. The patient stated that some 2o years ago he had two molars removed from his right lower jaw. Prior to this he had not been aware of any abnormality in colour of the adjacent mucosa. Thereafter, however, a 'purple channel' had persisted at the site of the extractions. Only during the past few months had this area appeared to increase in size. Some eight weeks ago the width of the area involved increased noticeably and polypoidal masses (3 in all) rose from the centre of the lesion. There had been no pain at any time, but a persistent foul taste in his month, particularly on rising had caused him to seek advice.
Clinical Examination. On clinical examination he was found to be in good general condition. Intra-oral examination revealed an extensive melanotic lesion involving the right lower alveolus from 7 - 3l approximately, extending into the buccal sulcus where there were several diffuse melanotic spots. There was no extension from the alveolar ridge to the lingual aspect. Arising from the centre of the main melanotic mass were three polypoidal growths showing surface ulceration. (Fig. I). His dentition was as follows: xx 432I / I23 5 7 32I / z234 Oral hygiene poor. There were no palpable regional lymph nodes, and radiographs of the mandible and chest produced no abnormal findings. T r e a t m e n t . On 8th September, 196z a biopsy was carried out under General Anaesthesia when the three polypoidal masses were excised and the wound sutured. The biopsy report indicated a diagnosis of malignant melanoma. The biopsy wound healed without incident and the 'foul taste' disappeared. The patient was referred to the Combined Plastic and Radiotherapy Clinic on 25th September, 50
"MELANOGENIC METAPLASIA" OF MUCOUS GLANDS
51
I96I when his future treatment was discussed. He was re-admitted to the Plastic Surgery Unit on 23rd October, I961 and on 24th October had caries teeth extracted 432I/. On 2nd November, I96I through a Criles incision a radical right sided dissection of the glands of the neck was carried out followed by complete hemi-resecfion of the right mandible and tumour in continuity. The wound was closed in layers. The convalescence was uneventful and on 1st December, r96I the patient was finally fitted with a partial upper denture prosthesis prior to discharge. No attempt was made other than by exercises to counteract the inevitable deviation of the mandible to the right so as to
FIG. I
Melanotic lesion of oral mucosa prior to biopsy.
place as little strain on the suture line as possible. An appliance to correct the deviation was not considered at this stage. Subsequent repair with a bone graft and denture will be largely dependent on the patient's own wishes. Cosmetically the operative result has not been as mutilating as is thought by many. This is usually the case if the mandibular hemi-resection is carried out distal to the canine tooth. The patient was last seen on 3oth January, I963 when his condition was entirely satisfactory. H i s t o p a t h o l o g y . i. Biopsy specimen: This showed the typical features of a malignant melanoma with conspicuous 'junctional change' in the overlying stratified squamous epithelium (Fig. 2A and B). Pigmentation varied considerably throughout the tumour but was in general only moderate, with occasional heavily pigmented areas. Both the spindle cell and the pseudoepithelial types of growth were present and mitoses were noted in considerable numbers. 2. Specimen from Dissection of Neck Glands and Hemi-Resection of Mandible: Tumour was not demonstrated in any of the lymph nodes, which showed 'reactive' changes only, and the main findings were in sections from the buccal mucosa and subjacent tissues.
52
BRITISH JOURNAL OF ORAL SURGERY
FIG. 2A and B A. Histopathology biopsy specimen. A general view of the turnout showing moderate pigmentation and well marked 'junctional change' in the overlying squamous epithelium. Haematoxylin and Eosin xlSO. B. High-power view of turnout margin showing more marked pigmentation and conspicuous 'junctional change'. Flaematoxylin and Eosin x 575.
"MELANOGENIC METAPLASIA" OF MUCOUS GLANDS
FIG. 3A and B A. Lobule of mucous gland showing marked pigmentation of duct and acini. Note the glandular atypia associated with the more extreme degrees of pigmentation. Haematoxylin and Eosin xI3o. B. High-power field from lower half of Fig. n. Note the abundant pigment, nuclear enlargement and hyperchromatism and the 'dissociation' of cells, closely resembling 'junctional change' in the squamous epithelium. Haematoxylin and Eosin x575.
53
54
BRITISH JOURNAL OF ORAL SURGERY
These revealed widespread 'junctional change' in the squamous epithelium with one or two areas of associated invasive growth constituting malignant melanoma morphologically similar to that of the biopsy. An incidental finding of arresting interest and great fundamental importance was the presence of pigmentation, glandular atypia and nuclear hyperchromatism in several lobules of submucosal mucous glands (Fig. 3A and B). The significance of this remarkable metaplasia, which casts doubt upon current concepts of the histogenesis of the melanomata, is considered in greater detail in a further paper which is in preparation. S u m m a r y . - - A case of malignant melanoma of the mouth, involving the mucosa of the lower alveolar ridge, is presented. The incidental findings are of note in that the mucous secreting cells actually appear to have produced melanin by virtue of an alteration in their metabolism--'melanogenic metaplasia'. REFERENCES DUCKWORTH, R. (1962).
Brit. dent. J., II3, 3, 73.
Maxillo-Facial and Plastic Surgery Unit, Bangour General Hospital and A. A. SHrVAS, M.D., D.P.H.
Department of Pathology, University of Edinburgh MALIGNANT Melanoma o f the m o u t h is, of itself, a relatively u n c o m m o n lesion, particularly when the mucosa of the lower alveolus is involved. (Duckworth, I962). T h e case reported is considered to be of especial interest, because of the unique incidental findings as indicated in the title. T h e presence o f mucous glands in the resected specimen which were seen to be actively participating in the widespread 'junctional change' affecting the superficial squamous epithelium, necessitates a critical reappraisal of the current views regarding the histogenesis of melanomata. CASE R E P O R T
History. Man, aged 56, Master Plumber. Referred on 23rd August, z96I as an out-patient at Edinburgh Dental Hospital because of 'bad taste' in mouth, believed to be associated with purple lesion in right alveolar region. The patient stated that some 2o years ago he had two molars removed from his right lower jaw. Prior to this he had not been aware of any abnormality in colour of the adjacent mucosa. Thereafter, however, a 'purple channel' had persisted at the site of the extractions. Only during the past few months had this area appeared to increase in size. Some eight weeks ago the width of the area involved increased noticeably and polypoidal masses (3 in all) rose from the centre of the lesion. There had been no pain at any time, but a persistent foul taste in his month, particularly on rising had caused him to seek advice.
Clinical Examination. On clinical examination he was found to be in good general condition. Intra-oral examination revealed an extensive melanotic lesion involving the right lower alveolus from 7 - 3l approximately, extending into the buccal sulcus where there were several diffuse melanotic spots. There was no extension from the alveolar ridge to the lingual aspect. Arising from the centre of the main melanotic mass were three polypoidal growths showing surface ulceration. (Fig. I). His dentition was as follows: xx 432I / I23 5 7 32I / z234 Oral hygiene poor. There were no palpable regional lymph nodes, and radiographs of the mandible and chest produced no abnormal findings. T r e a t m e n t . On 8th September, 196z a biopsy was carried out under General Anaesthesia when the three polypoidal masses were excised and the wound sutured. The biopsy report indicated a diagnosis of malignant melanoma. The biopsy wound healed without incident and the 'foul taste' disappeared. The patient was referred to the Combined Plastic and Radiotherapy Clinic on 25th September, 50
"MELANOGENIC METAPLASIA" OF MUCOUS GLANDS
51
I96I when his future treatment was discussed. He was re-admitted to the Plastic Surgery Unit on 23rd October, I961 and on 24th October had caries teeth extracted 432I/. On 2nd November, I96I through a Criles incision a radical right sided dissection of the glands of the neck was carried out followed by complete hemi-resecfion of the right mandible and tumour in continuity. The wound was closed in layers. The convalescence was uneventful and on 1st December, r96I the patient was finally fitted with a partial upper denture prosthesis prior to discharge. No attempt was made other than by exercises to counteract the inevitable deviation of the mandible to the right so as to
FIG. I
Melanotic lesion of oral mucosa prior to biopsy.
place as little strain on the suture line as possible. An appliance to correct the deviation was not considered at this stage. Subsequent repair with a bone graft and denture will be largely dependent on the patient's own wishes. Cosmetically the operative result has not been as mutilating as is thought by many. This is usually the case if the mandibular hemi-resection is carried out distal to the canine tooth. The patient was last seen on 3oth January, I963 when his condition was entirely satisfactory. H i s t o p a t h o l o g y . i. Biopsy specimen: This showed the typical features of a malignant melanoma with conspicuous 'junctional change' in the overlying stratified squamous epithelium (Fig. 2A and B). Pigmentation varied considerably throughout the tumour but was in general only moderate, with occasional heavily pigmented areas. Both the spindle cell and the pseudoepithelial types of growth were present and mitoses were noted in considerable numbers. 2. Specimen from Dissection of Neck Glands and Hemi-Resection of Mandible: Tumour was not demonstrated in any of the lymph nodes, which showed 'reactive' changes only, and the main findings were in sections from the buccal mucosa and subjacent tissues.
52
BRITISH JOURNAL OF ORAL SURGERY
FIG. 2A and B A. Histopathology biopsy specimen. A general view of the turnout showing moderate pigmentation and well marked 'junctional change' in the overlying squamous epithelium. Haematoxylin and Eosin xlSO. B. High-power view of turnout margin showing more marked pigmentation and conspicuous 'junctional change'. Flaematoxylin and Eosin x 575.
"MELANOGENIC METAPLASIA" OF MUCOUS GLANDS
FIG. 3A and B A. Lobule of mucous gland showing marked pigmentation of duct and acini. Note the glandular atypia associated with the more extreme degrees of pigmentation. Haematoxylin and Eosin xI3o. B. High-power field from lower half of Fig. n. Note the abundant pigment, nuclear enlargement and hyperchromatism and the 'dissociation' of cells, closely resembling 'junctional change' in the squamous epithelium. Haematoxylin and Eosin x575.
53
54
BRITISH JOURNAL OF ORAL SURGERY
These revealed widespread 'junctional change' in the squamous epithelium with one or two areas of associated invasive growth constituting malignant melanoma morphologically similar to that of the biopsy. An incidental finding of arresting interest and great fundamental importance was the presence of pigmentation, glandular atypia and nuclear hyperchromatism in several lobules of submucosal mucous glands (Fig. 3A and B). The significance of this remarkable metaplasia, which casts doubt upon current concepts of the histogenesis of the melanomata, is considered in greater detail in a further paper which is in preparation. S u m m a r y . - - A case of malignant melanoma of the mouth, involving the mucosa of the lower alveolar ridge, is presented. The incidental findings are of note in that the mucous secreting cells actually appear to have produced melanin by virtue of an alteration in their metabolism--'melanogenic metaplasia'. REFERENCES DUCKWORTH, R. (1962).
Brit. dent. J., II3, 3, 73.