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Plasmacytoma of the skull base
Clin. Radioh(1971) 22, 93-96 PLASMACYTOMA
OF
JAMES TOLAND
THE
SKULL
BASE
and P E T E R D. P H E L P S
From the Department of Radiology, Radcliffe Infirmary, Oxford
The authors describe a case o f so-called solitary p l a s m a c y t o m a o f the skull base in a 19 year old male who presented initially with l y m p h a d e n o p a t h y o f the left side o f the neck. This was subsequently followed by complaints o f tinnitus and deafness in the left ear. Skull radiographs revealed a large area o f erosion o f the skull base which p r o v e d to be due to a solitary plasmacytoma. In view o f the rarity o f such reports in the radiological literature, the clinical, p a t h o logical and r a d i o g r a p h i c features o f p l a s m a c y t o m a o f the skull base are reviewed.
PRIMARY t u m o u r s o f the cranial bones are rare. I n v o l v e m e n t o f the base o f the skull by so-called solitary p l a s m a c y t o m a is even rarer. W e have recently seen such a case in a 19 year old male in w h o m an extensive area o f destruction o f the base o f the skull was subsequently proved to be due to a solitary plasmacytoma. In the m o s t recent and authoritative text o n radiology o f the skull by D u Boulay (1965) no m e n t i o n o f this type o f lesion is made. CASE REPORT A boy of 19 with moderately severe, but controlled diabetes mellitus, developed generalised enlargement of the lymph nodes of the left side of the neck. Biopsy of the nodes showed only reactive hyperplasia. Six months later he complained of tinnitus and deafness in the left ear associated with dizziness. He was found to have a left serous otitis media, confirmed by paracentesis, combined conductive and sensorineural hearing loss in the left ear, and absent left caloric response. He appeared well, and there were no other abnormal neurological signs. X-ray of the skull, however, showed an extensive destructive lesion in the base of the skull
Fro. 1 Semi-subrnento-vertical view showing destruction skull base and petrous bone.
to the left of the midline (Fig 1). This involved the occipital bone behind and to the left of the foramen magnum, the left occipital condyle, the left petrous apex and the undersurface of the petrous bone, and the basisphenoid and basiocciput, including the left side of the sphenoid sinus (Fig. 2). Tomography showed destruction also of the lateral mass of the atlas. A mastoidectomy approach through a post-auricular incision revealed greyish-blue granulation tissue in the mastoid cortex and antrum. Histopathology showed loosely arranged sheets of cells of the plasma cell series. Some were of adult type, but there were a considerable number of binucleate forms, and a few had more than 2 nuclei. Occasional cells were undergoing mitosis. Except for a few lymphocytes and polymorphonuclear leukocytes, the picture was of a pure plasma cell proliferation. The previous lymph node biopsies were reviewed but were still considered to be non-specific. Extensive tests of blood cells and blood chemistry were undertaken, but were all found to be normal. Sternal marrow biopsy showed some reactive plasma cell changes, but plasma cells only formed 1-3 Yoof the nucleated cells present. No other bony changes were found in a radiological skeletal survey. Because of the lesion of the atlas bone he was fitted with a collar and admitted for radiotherapy in the hope that recalcification would occur.
FIG. 2 Half-axial view showing destruction of petrous and occiput on
of
the left side. 93
94
CLINICAL
FIG. 3 Two serial tomograms (A.P.) showing destruction of the left occipital condyle and lateral mass of the atlas and undersurface of the petrous bone. Three m o n t h s later, however, further t o m o g r a m s showed m o r e destruction o f the left side of the atlas (Fig 3). T h e destruction at the base o f the skull h a d extended forwards to involve the pituitary fossa. He was therefore given a further 2,500 rads to the t u m o u r . He was started o n oral cyclophosp h a m i d e 100 mg. b.d. later reduced to 50 mg. t.d.s. A t t h e present time, 2 years later, his condition r e m a i n s virtually u n c h a n g e d . His diabetes is well controlled by soluble insulin a n d there are n o further cranial nerve lesions. Skull X-rays s h o w further extension o f the erosion in the occiput, m a s t o i d a n d ethmoidal regions (Fig. 4). There is as yet n o sign o f systemic disease.
DISCUSSION INCIDENCE.---The rarity of involvement of the skull base by plasmacytoma is reflected in the numerous reports on multiple myeloma in the world literature. The first radiographic description of a solitary plasmacytoma affecting the skull base was recorded by Esposito (1943). Several isolated reports, followed and Clarke (1954) reviewed 24 adequately documented cases of myelomatous involvement of the skull base with cranial nerve palsies. He added a further case of his own. Of these 25 cases however, only 6 at the time of presentation were of the so-called solitary plasmacytoma variety. Hermann (1963) added a further case of solitary plasmacytoma and briefly reviewed the literature.
RADIOLOGY
FIG. 4 Oblique view of left mastoid showing extensive bone destruction with small additional operative defect.
The present case is the eighth example of solitary plastocytoma of the skull base, which at the time of presentation had no other evidence of myelomatosis. LocAuZATlON.---Plasmacytomas of the base of the skull are primarily extradural in origin. Rarely the tumour may invade and extend through the dura mater, but invasion of brain tissue is not thought to occur. Most of the lesions described have been located near the sphenoid and apex of the petrous bone. Sometimes the lesions, when first seen, have been so extensive that the exact site of origin has been difficult to determine, as in the present case. The only other case with involvement of the posterior fossa and petrous temporal bone, similar to the present one, was reported by Cappell and Mathers (1935). The tumour mass in their patient, a female aged 57, had completely replaced and destroyed the petrous temporal bone, the right side of the occipital bone around the foramen magnum and the right half of the basi-sphenoid and basi-occiput. The extent of involvement of the skull base with associated destruction of the left lateral mass of the atlas in the present case has not been previously recorded. The extension across the atlanto-occipital joint is not surprising because myeloma is known
P L A S M A C Y T O M A OF THE S K U L L BASE
to cross cartilage and involve adjacent bones. This phenomenon has been described in myeloma of the spine. Paul and Pohle (1940) reviewed several cases with a solitary plasmacytoma affecting 1 vertebral body. Follow-up studies showed later extension to adjacent vertebrae. Such an appearance is rarely encountered in carcinoma; an important differential feature. CLINICAL FEATURES.--Clarke 1.1954)classified cranial and intracranial myelomas into 3 clinical groups. Group I Syndromes of cranial nerve palsies. Group II Intracranial tumour syndromes. Group III Intra-orbitat tumour syndromes. Myelomas involving the skull base usually present with 1 or more cranial nerve lesions. Any cranial nerve may be affected singly or in combination, and Clarke notes that the VIth and VIIIth are most commonly involved. Headache, nasal obstruction, and endocrine disturbances due to pituitary damage are other presenting features. The tumour does not invade nervous tissue and any neurological dysfunction appears to be due to pressure effects. There is no correlation between the extent of the lesion and the degree of cranial nerve damage. The size and situation of the lesion in our case and in that of Cappell and Mathers (1935) were very similar, but whereas dysfunction of 6 cranial nerves was present in their patient, the only symptoms in our patient were referable to the VIIIth nerve. Moreover, these symptoms could have resulted from direct involvement due to the close proximity of the lesion to the internal ear. This preservation of cranial nerve function in the presence of such an extensive lesion is most unusual. The enlarged lymph nodes, 1 of the presenting features in our case, were presumably the result of reactive hyperplasia to the dissemination of plasma cells from the tumour. PATHOLOGV.--Three different varieties of plasma cell tumours have been described by Willis (1960). 1. Plasma Cell Myclomatosis.--This is the more common variety with diffuse skeletal involvement by soft tissue masses. The tumours are composed of plasma cells or a mixture of such cells and their precursors. Biochemical changes are often found in association with these lesions and include hyperglobulinaemia, Bence Jones proteinuria and hypercalcaemia. Such tumours are probably independent growths, the result of multifocal disease of the bone marrow. In some cases myeloma deposits, in the form of localised tumours or diffuse infiltration, are found in the viscera or other soft tissues. These lesions are thought to arise as a result of metastatic dissemination of tumour cells.
95
2. Solitary Plasmaeytoma of Bone.--Occasionally the first manifestation of myelomatosis is the appearance of a solitary discrete growth in a long bone. Often these lesions are followed months, or even several years later, by multiple skeletal tumours. Large solitary destructive lesions of bone which have not been followed by the development o f turnout elsewhere in the skeleton have, however, been reported (Stewart and Taylor, 1932; Willis, 1941; Lumb, 1952). Yentis (1956) in a critical review of previously published cases casts considerable doubt on the existence of solitary plasmacytoma as a distinct and isolated pathological entity. The weight of evidence indicates that so-called solitary plasmacytoma eventually progresses to diffuse myelomatosis (Griffiths, 1955).
3. Primary Plasmacytoma of Soft Tissues.---These extra-medullary lesions present as soft tissue masses arising in the mucous membranes and submucous tissues of the gastro-intestinal and respiratory passages of the head and neck. They are important to the present discussion when situated adjacent to bone. They may produce such extensive destruction that the exact site of origin of the lesion cannot be determined (Stewart and Taylor, 1932; Cappel and Mathers, 1933). RADIOGRAPHIC FEATURES.--Plasmacytomas are often very large lesions when first detected radiographically. They are invariably osteolytic in nature, although a recent paper by Evison and Evans (1967) described sclerotic reaction in myelomatous involvement of the spinal column.. Two radiological varieties occur. The first is characterized by an osteolytic multicystic area o f rarefaction with sharply defined margins. The area of destruction is crossed by irregular and sometimes thick trabeculae. Destruction of cortex may occur. N o periosteal reaction is noted. The second variety is a purely destructive nontrabeculated lesion and closely resembles metastatic disease. DIFFERENTIAL RADIOLOGICAL DIAGNOSIS.---There are no distinctive radiographic features of plasmacytoma of the skull base. Other lesions involving the skull base may produce similar radiographic appearances. Consideration of the site and extent of the erosive changes and the associated clinical features may assist the differential diagnosis. Chordomas typically arise in the mid-line and may produce all degrees of erosion but are characteristically associated with destruction of the clivus and adjacent part of the sella. Some sclerosis of uneroded bone or calcification in the tumour may be recognized. Metastatic lesions with destruction o f the bones of the skull base typically produce an
96
CLINICAL
RADIOLOGY
ill-defined erosion not accompanied by sclerotic associated with well defined margins often with a bone reaction. In naso-pharyngeal tumours, scalloped and sclerotic outline. recognition of a soft-tissue mass in the nasopharynx m a y provide the clue to the correct diagnosis. This feature however m a y also rarely be associated with p l a s m a c y t o m a of the skull base (Clarke's first case, 1954). Primary neoplasm of the sphenoid or petrous bones will produce appearances indistinguishable from those described in association with basal myelomas. Bone destruction in eosinophilie granuloma m a y at times be quite extensive, and the entire thickness of the skull over a wide area m a y be destroyed. The outline of the eroded area is irregular a n d usually without s u r r o u n d i n g sclerosis. The m a r g i n of the bone defect is invariably sharply defined. Such lesions tend to occur in the young. Glomus tumours are associated with a n irregular area of b o n e destruction c o n t i n u o u s with the translucency of the j u g u l a r foramen. I n most cases, the f o r a m e n itself will be enlarged with ill-defined margins. Meningiomas are generally associated with hyperostosis when they are attached to the skull base. Lesions have been described, however, with a n ill-defined area of bone destruction, often indistinguishable from invasion due to a m a l i g n a n t neoplasm. Epidermoids of the skull base are rare a n d are
REFERENCES CAPELL, D. F. 8l; MATHERS, R. P. (1935). Plasmaeytoma of
the Petrous Temporal Bone and Base of Skull. Journal of Laryngology and Otology, 50, 340-349. CLARKE, E. (1954). Cranial and Intracranial Myelomas. Brain, 77, 61-81. Du BOULAY,G. H. (1965). Principles of X-Ray Diagnosis of the Skull. Butterworths. EsPoslzo, J. J. (1943). Case of Solitary Myeloma of Skull. Radiology, 40, 195-197. EVISON,G. ~; EVANS,K. T. (1967). Bone Sclerosis in Multiple Myeloma. British Journal of Radiology, 40, 81-89. GRtFFITHS,D. L. (1955). In Modern Trends in Pathology. Butterworths. HERRMANN,E. (1963). Dos Plasmocytom Der Sch~idelBasis. Archiv. Fur Psychiatrie und Zeitschrift F.D. Ges Neurologic, 204, 262-270. LUMB, G. (1948). Solitary Plasmacytoma of Bone with Renal Changes. British Journal of Surgery, 36, i6-22. PAUL, L. W. & POHLE, E. A. (1940). Solitary Myeloma of Bone: Review of Roentgenologic Features with Report of 4 additional cases. Radiology, 35, 230-232. STEWART,M. J. & TAYLOR,A. L. (1932). Observations on Solitary Plasmacytoma. Journal of Pathology and Bacteriofogy, 35, 541-547. WmLIS, R. A. (1960). Pathology of Tumours. 3rd Edition. Butterworths. WtLLIS, R. A. (1941). Solitary Plasmacytoma of Bone. Journal of Pathology and Bacteriology, 53, 77-85. YE~S, I. (1956). The So-called Solitary Plasmacytoma of Bone. Journal of the Faculty of Radiologists, 8, 132-144.
NOTICES BRITISH RADIOLOGICAL PROTECTION ASSOCIATION Preliminary Notice of an all-day Scientific Meeting organised by the Society for Radiological Protection, Imperial College, South Kensington, London, on the 23rd March, 1971.
RADIOLOGY/ASPEN ASPEN Conference on Radiology and the New Technology. Diagnostic Radiology, Naclear Medicine and Radiation Therapy. To be held at Aspen, Colorado from 23rd to 27th March, 1971. A Conference sponsored by the Division of Radiology, Denver General Hospital, Denver, Colorado.
'Radiological Protection and Society' Part I - Radiation Hazards - The Scientists' Interpretation. (a) Somatic Effects- Dr. R. H. Mole, Director, MRC Radiobiology Unit, Harwell. (b) Genetic Effects- Prof. H. J. Evans, MRC Clinical & Pop. Cytogeneties Unit, Western General Hospital, Edinburgh. (c) Cost-Benefit Relationships in the Use of RadiationDr. Bo Lindell, Nat. Inst. of Rod. Protection, Stockholm. (d) Cost-Benefit Relationships in General Safety Practice Mr. Craig Sinclair, University of Sussex, Brighton. Part I I - Radiation Hazards- The Viewpoint of Society. (a) Unsafe at any Dose - Lord Ritchie-Calder, Edinburgh. (b) Public Attitudes to the A t o m - Dr. Donald Gould, London. (c) Legal Considerations- Mr. R. W. Howells, Hendon College of Technology, London. Their will be Panel Discussion. Final programmes and arrangements for registration will be circulated later.
THE CANADIAN ASSOCIATION OF RADIOLOGISTS L'ASSOCIATION CANADIENNE DES RADIOLOGISTES The 34th Annual Meeting of the Canadian Association of Radiologists will be held at the Palliser Hotel, Calgary, 16th-19th March, 1971. The Scientific Program Committee invites radiologists, physicists, etc. to submit papers and scientific exhibits for this meeting. All communications should be sent to: Chairman, Scientific Program Committee, the Canadian Association of Radiologists, Suite 101, 1555 Summerhill Avenue, Montreal 109, P.Q.
OF
JAMES TOLAND
THE
SKULL
BASE
and P E T E R D. P H E L P S
From the Department of Radiology, Radcliffe Infirmary, Oxford
The authors describe a case o f so-called solitary p l a s m a c y t o m a o f the skull base in a 19 year old male who presented initially with l y m p h a d e n o p a t h y o f the left side o f the neck. This was subsequently followed by complaints o f tinnitus and deafness in the left ear. Skull radiographs revealed a large area o f erosion o f the skull base which p r o v e d to be due to a solitary plasmacytoma. In view o f the rarity o f such reports in the radiological literature, the clinical, p a t h o logical and r a d i o g r a p h i c features o f p l a s m a c y t o m a o f the skull base are reviewed.
PRIMARY t u m o u r s o f the cranial bones are rare. I n v o l v e m e n t o f the base o f the skull by so-called solitary p l a s m a c y t o m a is even rarer. W e have recently seen such a case in a 19 year old male in w h o m an extensive area o f destruction o f the base o f the skull was subsequently proved to be due to a solitary plasmacytoma. In the m o s t recent and authoritative text o n radiology o f the skull by D u Boulay (1965) no m e n t i o n o f this type o f lesion is made. CASE REPORT A boy of 19 with moderately severe, but controlled diabetes mellitus, developed generalised enlargement of the lymph nodes of the left side of the neck. Biopsy of the nodes showed only reactive hyperplasia. Six months later he complained of tinnitus and deafness in the left ear associated with dizziness. He was found to have a left serous otitis media, confirmed by paracentesis, combined conductive and sensorineural hearing loss in the left ear, and absent left caloric response. He appeared well, and there were no other abnormal neurological signs. X-ray of the skull, however, showed an extensive destructive lesion in the base of the skull
Fro. 1 Semi-subrnento-vertical view showing destruction skull base and petrous bone.
to the left of the midline (Fig 1). This involved the occipital bone behind and to the left of the foramen magnum, the left occipital condyle, the left petrous apex and the undersurface of the petrous bone, and the basisphenoid and basiocciput, including the left side of the sphenoid sinus (Fig. 2). Tomography showed destruction also of the lateral mass of the atlas. A mastoidectomy approach through a post-auricular incision revealed greyish-blue granulation tissue in the mastoid cortex and antrum. Histopathology showed loosely arranged sheets of cells of the plasma cell series. Some were of adult type, but there were a considerable number of binucleate forms, and a few had more than 2 nuclei. Occasional cells were undergoing mitosis. Except for a few lymphocytes and polymorphonuclear leukocytes, the picture was of a pure plasma cell proliferation. The previous lymph node biopsies were reviewed but were still considered to be non-specific. Extensive tests of blood cells and blood chemistry were undertaken, but were all found to be normal. Sternal marrow biopsy showed some reactive plasma cell changes, but plasma cells only formed 1-3 Yoof the nucleated cells present. No other bony changes were found in a radiological skeletal survey. Because of the lesion of the atlas bone he was fitted with a collar and admitted for radiotherapy in the hope that recalcification would occur.
FIG. 2 Half-axial view showing destruction of petrous and occiput on
of
the left side. 93
94
CLINICAL
FIG. 3 Two serial tomograms (A.P.) showing destruction of the left occipital condyle and lateral mass of the atlas and undersurface of the petrous bone. Three m o n t h s later, however, further t o m o g r a m s showed m o r e destruction o f the left side of the atlas (Fig 3). T h e destruction at the base o f the skull h a d extended forwards to involve the pituitary fossa. He was therefore given a further 2,500 rads to the t u m o u r . He was started o n oral cyclophosp h a m i d e 100 mg. b.d. later reduced to 50 mg. t.d.s. A t t h e present time, 2 years later, his condition r e m a i n s virtually u n c h a n g e d . His diabetes is well controlled by soluble insulin a n d there are n o further cranial nerve lesions. Skull X-rays s h o w further extension o f the erosion in the occiput, m a s t o i d a n d ethmoidal regions (Fig. 4). There is as yet n o sign o f systemic disease.
DISCUSSION INCIDENCE.---The rarity of involvement of the skull base by plasmacytoma is reflected in the numerous reports on multiple myeloma in the world literature. The first radiographic description of a solitary plasmacytoma affecting the skull base was recorded by Esposito (1943). Several isolated reports, followed and Clarke (1954) reviewed 24 adequately documented cases of myelomatous involvement of the skull base with cranial nerve palsies. He added a further case of his own. Of these 25 cases however, only 6 at the time of presentation were of the so-called solitary plasmacytoma variety. Hermann (1963) added a further case of solitary plasmacytoma and briefly reviewed the literature.
RADIOLOGY
FIG. 4 Oblique view of left mastoid showing extensive bone destruction with small additional operative defect.
The present case is the eighth example of solitary plastocytoma of the skull base, which at the time of presentation had no other evidence of myelomatosis. LocAuZATlON.---Plasmacytomas of the base of the skull are primarily extradural in origin. Rarely the tumour may invade and extend through the dura mater, but invasion of brain tissue is not thought to occur. Most of the lesions described have been located near the sphenoid and apex of the petrous bone. Sometimes the lesions, when first seen, have been so extensive that the exact site of origin has been difficult to determine, as in the present case. The only other case with involvement of the posterior fossa and petrous temporal bone, similar to the present one, was reported by Cappell and Mathers (1935). The tumour mass in their patient, a female aged 57, had completely replaced and destroyed the petrous temporal bone, the right side of the occipital bone around the foramen magnum and the right half of the basi-sphenoid and basi-occiput. The extent of involvement of the skull base with associated destruction of the left lateral mass of the atlas in the present case has not been previously recorded. The extension across the atlanto-occipital joint is not surprising because myeloma is known
P L A S M A C Y T O M A OF THE S K U L L BASE
to cross cartilage and involve adjacent bones. This phenomenon has been described in myeloma of the spine. Paul and Pohle (1940) reviewed several cases with a solitary plasmacytoma affecting 1 vertebral body. Follow-up studies showed later extension to adjacent vertebrae. Such an appearance is rarely encountered in carcinoma; an important differential feature. CLINICAL FEATURES.--Clarke 1.1954)classified cranial and intracranial myelomas into 3 clinical groups. Group I Syndromes of cranial nerve palsies. Group II Intracranial tumour syndromes. Group III Intra-orbitat tumour syndromes. Myelomas involving the skull base usually present with 1 or more cranial nerve lesions. Any cranial nerve may be affected singly or in combination, and Clarke notes that the VIth and VIIIth are most commonly involved. Headache, nasal obstruction, and endocrine disturbances due to pituitary damage are other presenting features. The tumour does not invade nervous tissue and any neurological dysfunction appears to be due to pressure effects. There is no correlation between the extent of the lesion and the degree of cranial nerve damage. The size and situation of the lesion in our case and in that of Cappell and Mathers (1935) were very similar, but whereas dysfunction of 6 cranial nerves was present in their patient, the only symptoms in our patient were referable to the VIIIth nerve. Moreover, these symptoms could have resulted from direct involvement due to the close proximity of the lesion to the internal ear. This preservation of cranial nerve function in the presence of such an extensive lesion is most unusual. The enlarged lymph nodes, 1 of the presenting features in our case, were presumably the result of reactive hyperplasia to the dissemination of plasma cells from the tumour. PATHOLOGV.--Three different varieties of plasma cell tumours have been described by Willis (1960). 1. Plasma Cell Myclomatosis.--This is the more common variety with diffuse skeletal involvement by soft tissue masses. The tumours are composed of plasma cells or a mixture of such cells and their precursors. Biochemical changes are often found in association with these lesions and include hyperglobulinaemia, Bence Jones proteinuria and hypercalcaemia. Such tumours are probably independent growths, the result of multifocal disease of the bone marrow. In some cases myeloma deposits, in the form of localised tumours or diffuse infiltration, are found in the viscera or other soft tissues. These lesions are thought to arise as a result of metastatic dissemination of tumour cells.
95
2. Solitary Plasmaeytoma of Bone.--Occasionally the first manifestation of myelomatosis is the appearance of a solitary discrete growth in a long bone. Often these lesions are followed months, or even several years later, by multiple skeletal tumours. Large solitary destructive lesions of bone which have not been followed by the development o f turnout elsewhere in the skeleton have, however, been reported (Stewart and Taylor, 1932; Willis, 1941; Lumb, 1952). Yentis (1956) in a critical review of previously published cases casts considerable doubt on the existence of solitary plasmacytoma as a distinct and isolated pathological entity. The weight of evidence indicates that so-called solitary plasmacytoma eventually progresses to diffuse myelomatosis (Griffiths, 1955).
3. Primary Plasmacytoma of Soft Tissues.---These extra-medullary lesions present as soft tissue masses arising in the mucous membranes and submucous tissues of the gastro-intestinal and respiratory passages of the head and neck. They are important to the present discussion when situated adjacent to bone. They may produce such extensive destruction that the exact site of origin of the lesion cannot be determined (Stewart and Taylor, 1932; Cappel and Mathers, 1933). RADIOGRAPHIC FEATURES.--Plasmacytomas are often very large lesions when first detected radiographically. They are invariably osteolytic in nature, although a recent paper by Evison and Evans (1967) described sclerotic reaction in myelomatous involvement of the spinal column.. Two radiological varieties occur. The first is characterized by an osteolytic multicystic area o f rarefaction with sharply defined margins. The area of destruction is crossed by irregular and sometimes thick trabeculae. Destruction of cortex may occur. N o periosteal reaction is noted. The second variety is a purely destructive nontrabeculated lesion and closely resembles metastatic disease. DIFFERENTIAL RADIOLOGICAL DIAGNOSIS.---There are no distinctive radiographic features of plasmacytoma of the skull base. Other lesions involving the skull base may produce similar radiographic appearances. Consideration of the site and extent of the erosive changes and the associated clinical features may assist the differential diagnosis. Chordomas typically arise in the mid-line and may produce all degrees of erosion but are characteristically associated with destruction of the clivus and adjacent part of the sella. Some sclerosis of uneroded bone or calcification in the tumour may be recognized. Metastatic lesions with destruction o f the bones of the skull base typically produce an
96
CLINICAL
RADIOLOGY
ill-defined erosion not accompanied by sclerotic associated with well defined margins often with a bone reaction. In naso-pharyngeal tumours, scalloped and sclerotic outline. recognition of a soft-tissue mass in the nasopharynx m a y provide the clue to the correct diagnosis. This feature however m a y also rarely be associated with p l a s m a c y t o m a of the skull base (Clarke's first case, 1954). Primary neoplasm of the sphenoid or petrous bones will produce appearances indistinguishable from those described in association with basal myelomas. Bone destruction in eosinophilie granuloma m a y at times be quite extensive, and the entire thickness of the skull over a wide area m a y be destroyed. The outline of the eroded area is irregular a n d usually without s u r r o u n d i n g sclerosis. The m a r g i n of the bone defect is invariably sharply defined. Such lesions tend to occur in the young. Glomus tumours are associated with a n irregular area of b o n e destruction c o n t i n u o u s with the translucency of the j u g u l a r foramen. I n most cases, the f o r a m e n itself will be enlarged with ill-defined margins. Meningiomas are generally associated with hyperostosis when they are attached to the skull base. Lesions have been described, however, with a n ill-defined area of bone destruction, often indistinguishable from invasion due to a m a l i g n a n t neoplasm. Epidermoids of the skull base are rare a n d are
REFERENCES CAPELL, D. F. 8l; MATHERS, R. P. (1935). Plasmaeytoma of
the Petrous Temporal Bone and Base of Skull. Journal of Laryngology and Otology, 50, 340-349. CLARKE, E. (1954). Cranial and Intracranial Myelomas. Brain, 77, 61-81. Du BOULAY,G. H. (1965). Principles of X-Ray Diagnosis of the Skull. Butterworths. EsPoslzo, J. J. (1943). Case of Solitary Myeloma of Skull. Radiology, 40, 195-197. EVISON,G. ~; EVANS,K. T. (1967). Bone Sclerosis in Multiple Myeloma. British Journal of Radiology, 40, 81-89. GRtFFITHS,D. L. (1955). In Modern Trends in Pathology. Butterworths. HERRMANN,E. (1963). Dos Plasmocytom Der Sch~idelBasis. Archiv. Fur Psychiatrie und Zeitschrift F.D. Ges Neurologic, 204, 262-270. LUMB, G. (1948). Solitary Plasmacytoma of Bone with Renal Changes. British Journal of Surgery, 36, i6-22. PAUL, L. W. & POHLE, E. A. (1940). Solitary Myeloma of Bone: Review of Roentgenologic Features with Report of 4 additional cases. Radiology, 35, 230-232. STEWART,M. J. & TAYLOR,A. L. (1932). Observations on Solitary Plasmacytoma. Journal of Pathology and Bacteriofogy, 35, 541-547. WmLIS, R. A. (1960). Pathology of Tumours. 3rd Edition. Butterworths. WtLLIS, R. A. (1941). Solitary Plasmacytoma of Bone. Journal of Pathology and Bacteriology, 53, 77-85. YE~S, I. (1956). The So-called Solitary Plasmacytoma of Bone. Journal of the Faculty of Radiologists, 8, 132-144.
NOTICES BRITISH RADIOLOGICAL PROTECTION ASSOCIATION Preliminary Notice of an all-day Scientific Meeting organised by the Society for Radiological Protection, Imperial College, South Kensington, London, on the 23rd March, 1971.
RADIOLOGY/ASPEN ASPEN Conference on Radiology and the New Technology. Diagnostic Radiology, Naclear Medicine and Radiation Therapy. To be held at Aspen, Colorado from 23rd to 27th March, 1971. A Conference sponsored by the Division of Radiology, Denver General Hospital, Denver, Colorado.
'Radiological Protection and Society' Part I - Radiation Hazards - The Scientists' Interpretation. (a) Somatic Effects- Dr. R. H. Mole, Director, MRC Radiobiology Unit, Harwell. (b) Genetic Effects- Prof. H. J. Evans, MRC Clinical & Pop. Cytogeneties Unit, Western General Hospital, Edinburgh. (c) Cost-Benefit Relationships in the Use of RadiationDr. Bo Lindell, Nat. Inst. of Rod. Protection, Stockholm. (d) Cost-Benefit Relationships in General Safety Practice Mr. Craig Sinclair, University of Sussex, Brighton. Part I I - Radiation Hazards- The Viewpoint of Society. (a) Unsafe at any Dose - Lord Ritchie-Calder, Edinburgh. (b) Public Attitudes to the A t o m - Dr. Donald Gould, London. (c) Legal Considerations- Mr. R. W. Howells, Hendon College of Technology, London. Their will be Panel Discussion. Final programmes and arrangements for registration will be circulated later.
THE CANADIAN ASSOCIATION OF RADIOLOGISTS L'ASSOCIATION CANADIENNE DES RADIOLOGISTES The 34th Annual Meeting of the Canadian Association of Radiologists will be held at the Palliser Hotel, Calgary, 16th-19th March, 1971. The Scientific Program Committee invites radiologists, physicists, etc. to submit papers and scientific exhibits for this meeting. All communications should be sent to: Chairman, Scientific Program Committee, the Canadian Association of Radiologists, Suite 101, 1555 Summerhill Avenue, Montreal 109, P.Q.