Final Diagnosis -- Giant cell tumor of the sellar region


Giant cell tumor of the sellar region


The clinical and radiological impressions were those of a pituitary adenoma (PA) the most common sellar and parasellar lesion. The differential diagnosis of a non-functioning PA is extensive and includes cysts (Rathke's cleft, arachnoid), tumors (craniopharyngioma, meningioma, lymphoma, germ cell and metastatic tumors), aneurysm, granulomatous/inflammatory lesions (lymphocytic hypophysitis, histiocytosis, sarcoidosis, Wegener's granulomatosis) and infections (tuberculosis) [1, 2]. In the present case, the radiological findings and the hormonal levels were consistent with non-functioning PA. However, the clinical course was faster, the patient younger than usual (peak incidence between the 4th and 6th decades of life) and surgical appearance was not that of a PA.

GCT occurs mainly in the 3rd decade of life, with a slight preponderance in females and is considered a benign lesion, although locally aggressive, with bone destruction and tendency to local recurrence (3, 8). It is classically found in the epiphyses of long bones (distal femur, proximal tibia and fibula, distal radius and ulna) and represents about 2.4% to 5% of all primary bone tumors in adults. It is rarely located in the skull (2%), mostly in the ethmoid and sphenoid bones, particularly in the latter (5, 7). As reported by Weber et al. (7), due to tumor growth in the skull base (mainly in the sphenoid bone), it is not infrequent the destruction of the sella and, consequently, involvement of the pituitary gland, as previously reported on few occasions (6). In this case, there was hyperprolactinemia secondary to stalk compression and, as demonstrated by MRI, the epicenter of the mass is located inside the sella.

Histologically, there are very large multinucleated giant (osteoclast-like) cells, containing numerous nuclei (7,8) The stromal cell (spindle or ovoid, similar to histiocytes) constitutes the true neoplastic cells, from an osteoblastic origin. They stimulate the formation and differentiation of osteoclasts from precursor cells of monocytic lineage indicating that giant cells are in fact reactive and not the neoplastic cells. Stromal cells also induce the formation of reactive bone (9). Malignant forms, with a sarcomatous stroma, mitoses and a predominance of mononuclear over multinucleated giant cells, are not uncommon, and are likely to metastasize to the lungs (3, 8).

Differential diagnosis on morphological basis (with lesions containing giant cells) may be difficult and should include clinical and radiological data. The patient does not have hyperparathyroidism, therefore a brown tumor was discarded. The appearances where not those of a giant cell reparative granuloma (solid aneurismal bone cyst), in which spindle cells in a collagenous stroma predominate and multinucleated giant cells are not so large as in our case. In addition, it is seen in the maxillary, mandibular and short tubular bones of hands and feet and only rarely in cranial bones (4).

This case illustrates that differential diagnosis of non-functioning sellar/parasellar lesions is challenging due to clinical and radiological similarities among them, and that patients harboring large non-functioning sellar lesions without a definitive diagnosis should be operated to have the precise histological diagnosis and the best therapeutic management.


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  2. Freda PU, Wardlaw SL, Post KD (1996) Unusual causes of sellar/ parasellar masses in a large transsphenoidal surgical series. J Clin Endocrinol Metab 81:3455-3459.
  3. Klenke FM, Wenger DE, Inwards CY, Rose PS, Sim FH (2011) Giant cell tumor of bone risk factors for recurrence. Clin Orthop Relat Res 469:591-599.
  4. Saw S, Thomas N, Gleeson MJ, Bódi I, Connor S, Hortobágyi T (2009). Giant cell tumour and central giant cell reparative granuloma of the skull: do these represent ends of a spectrum? A case report and literature review. Pathol Oncol Res 15:291-5.
  5. Sharma RR, Mahapatra AK, Pawar SJ, Sousa J, Dev EJ (2002). Craniospinal giant cell tumors: clinicoradiological analysis in a series of 11 cases. J Clin Neurosci 9:41-50.
  6. Viale GL (1977). Giant cell tumours of the sellar region. Acta Neurochir (Wien) 38:259-68.
  7. Weber AL, Hug EB, Muenter MW, Curtin HD (1997) Giant-cell tumors of the sphenoid bone in four children: radiological, clinical, and pathological findings. Skull base surgery 7:163-173.
  8. Werner M. (2006). Giant cell tumour of bone: morphological, biological and histogenetical aspects. Int Orthop 30:484-489.
  9. Wuelling M, Delling G, Kaiser, E (2003). The origin of the neoplastic stromal cell in giant cell tumor of bone. Hum Pathol 34:983-993.

Contributed by Mônica R. Gadelha, Leonardo Vieira Neto, Juliana Malheiros Giorgetta, Paulo José da Mata Pereira, Paulo Niemeyer Filho, Leila Chimelli

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