J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.47.12.1348 on 1 December 1984. Downloaded from

Journal ofNeurology, Neurosurgery, and Psychiatry 1984;47: 1348-1350

Short report of the skull

MICHAEL FEELY, CATHERINE KEOHANE From the Departments ofNeurosurgery and Histopathology, Cork Regional Hospital, Wilton, Cork, Eire

SUMMARY A case of chondroblastoma of the temporal bone is reported, and the pathology of the lesion outlined. The rarity of these in the skull makes accurate prognosis impossible.

Chondroblastoma, also called "benign chondroblas- Pathology toma" is an uncommon of bone described Macroscopically the tumour consisted of gritty orange and by Codman' and given its present name by Jaffe and grey tissue and some white glistening fragments. Unde- Lichtenstein.2 The tumour usually occurs in the long calcified paraffin sections were stained by the following methods; haematoxylin/eosin, van Gieson, reticulin (Gor- bones3 but two cases arising from the skull have don and Sweet), alcian blue/PAS and ferrous ferricyanide. been reported.45 We describe a third case, different By light microscopy the tumour was composed of closely guest. Protected by copyright. from those previously recorded, as the tumour packed cellular areas alternating with loosely arranged extended through the dura, causing raised intracra- nodules showing cartilaginous differentiation (fig (a)). In nial pressure. the cellular regions, were polyhedral, and had single round vesicular nuclei; many contained cyto- Case report plasmic haemosiderin granules. There were unevenly scat- tered multinucleated giant cells having an average of 12 A 42-year-old female gave a four month history of seiz- uniformly sized round nuclei (fig (b)). The giant cells were ures, and pain in the left ear. On examination, she was sometimes seen in relation to foci of haemorrhage. Cal- drowsy, and had bilateral papilloedema. Ear inspection cium granules were also present, both within cell cyto- and clinical hearing tests were normal. Skull radiographs plasm, and deposited in lattice like fashion in inter cellular and tomograms of the left petrous bone, showed erosion, ground substance. Where cells and ground substance were and a CT scan showed a contrast-enhancing mass, arising heavily calcified the tissue was necrotic: "calcification nec- from the floor of the left middle fossa. There was oedema rosis." The tumour invaded through the dura, and replaced of the surrounding brain and contralateral shift. Angiogra- much of the bone removed from the middle ear at the phy demonstrated a tumour blush filling from the external second operation, although tumour had not been identified carotid, and the left internal carotid artery was occluded at at surgery. the skull base. A left temporal craniotomy was performed, and a soft friable extradural mass was found invading the Electronmicroscopy dura and elevating the temporal lobe. The intradural por- (Paraffin blocks were re-processed). Where cells were tion of tumour and visibly involved petrous bone was closely packed, cell membranes were indistinct, but some removed. The facial nerve was surrounded by tumour and had indentations or "bays" into which the electron-lucent was sectioned during surgery. Frozen section was not diag- intercellular matrix extended. Abundant rough endo- http://jnnp.bmj.com/ nostic; paraffin histology showed a chrondroblastoma. plasmic reticulum, prominent Golgi complexes and Once the nature and locally invasive character of the lesion intracytoplasmic granules of iron were other features of was known, a further resection was undertaken. At opera- these cells. Nuclei were markedly indented (fig (c)). There tion, residual tumour was not readily identifiable. The roof was a fine gradation between these closely packed cellular and anterior wall of the external auditory canal and middle regions and areas of cartilaginous differentiation, with ear were removed. Apart from a temporary CSF leak from increasing collagen in the ground substance and reticular her left ear, the patient made a good recovery. Three years calcium deposition around chondrocytes. after surgery, she remains well, except for left sided deaf- on September 25, 2021 by ness and facial palsy. Discussion Address for reprint requests: Mr MP Feely, Cork Regional Hospi- tal, Wilton, Cork, Eire. The commoner destructive neoplasms involving the Received 24 September 1982 and in revised form 22 April 1984. skull include; primary carcinomas of ear, sinuses and Accepted 16 June 1984 nasopharynx, metastatic carcinoma, meningioma, 1348 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.47.12.1348 on 1 December 1984. Downloaded from

Chondroblastoma of the skufll141349

4.

~~~~>\4~~N- 4~~~~~4

6w guest. Protected by copyright. 6MM

RI

NII~ ~ ~ ~ *

Fig (a) Alternating cellular and cartilaginous tisue. (HVG X SO) Fig (b) Chondroblasts and muldtnucleated giant cells. (H/E x 100) Fig (c) Highly convoluted nucleus and irregular cell membrane. The cytoplasmic electron dense granules are iron X 33 000. http://jnnp.bmj.com/ schwannoma, glomus jugulare tumour, chordoma dromatous giant cell tumour. There is a predomi- and . Osseous and cartilaginous nance of male cases and most patients are between skull tumours are less common, but , the ages of 10 and 25 years. The long bones, espe- , , , and giant cially the lower end of femur, upper ends of tibia cell tumour have all been described. In particular, and humerus are the most common sites. The cell of

the sphenoid and temporal bones, whose origin is by origin is thought to be a primitive cartilage cell.3 on September 25, 2021 by endochondral ossification may give rise to car- Microscopically the tumour can be confused with tilaginous neoplasms. chondrosarcoma or giant cell tumour and may be Benign chondroblastoma is an uncommon prim- worrying because of its extreme cellularity and var- ary neoplasm of bone, described in the past as "cal- iability. Mfitoses however, are scanty. The histologi- cifying giant cell tumour" and epiphyseal chon- cal hall mark is calcification necrosis where intercel- J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.47.12.1348 on 1 December 1984. Downloaded from

1350 Feely, Keohane lular calcification is dense. This was a pronounced References feature of our case. In long bones the tumour usually has a benign 'Codman EA. Epiphyseal chondromatous giant cell tumours of the upper end of the humerus. Surg behaviour and treatment by curettage is generally Gynaecol Obst 1931;52:543-8. curative, although an overall recurrence rate of 38% 2 Jaffe HL, Lichtenstein L. Benign chondroblastoma of has been reported in one series.6 One case in the bone. A re-interpretation of the so-called calcifying humerus developed sarcomatous change 3½/2 years or chondromatous giant cell tumour. Am J Pathol following treatment by curettage and radiation.7 1943; 18:969-83. Despite the usual benign course, there are reports of 3Jaffe HL. Tumours and Tumorous Conditions of the metastases to lung, liver and abdominal viscera.89 Bones and Joints. Philadelphia. Lea and Febiger, In the two previously recorded examples arising 1958. skull. the no term follow-up is men- Cares HL, Terplan K. Chondroblastoma of the from skull, long Case Reports. J Neurosurg 1971;35:614-8. tioned,45 so the prognosis in this location remains Denko JV, Krauel LH. Benign chondroblastoma of uncertain. The behaviour of the tumour in our case, bone: An unusual localisation in temporal bone. Arch invading the dura and causing increased intracranial Path 1955;59:710-1. pressure indicates that these may be, at least on 6 Huvos Andrew G, Marcove Ralph C, Erlandson Robert occasion, life threatening neoplasms. Therefore, it A, Mike Valerie. Chondroblastoma of bone. A would seem advisable to attempt a complete surgical clinicopathologic and Electromicroscopic study. removal, even if a second operation is involved, Cancer 1972;29:760-71. especially in view of the possibility of sarcomatous Hatcher CH, Campbell JC. Benign chondroblastoma of in chondroblastoma irradiation. bone: Its histologic variations and a report of Late change following in the site of one. Bull Hosp Joint Dis 1951; 12:411. Kahn LR, Wood FM, Ackerman LV. Malignant guest. Protected by copyright. chondroblastoma. Report of two cases and review of Our thanks are due to Dr M Catto for reviewing the literature. Arch Pathol 1969;88:371-6. histology, Prof. EC Sweeney for electronmicros- Sweetman R, Ross K. Surgical treatment of pulmonary copy, Mr C Kennefick ENT Surgeon, and Miss M metastases from primary tumours of bone. J Bone Power for secretarial help. Joint Surg 1967;49B: 74-9. http://jnnp.bmj.com/ on September 25, 2021 by