INTRODUCTION
Giant Cell Tumor of Bone (GCTB) is uncommon benign lesion, but locally
aggressive that most frequently affecting the epiphysis of long bones
especially around the knee [1]. The epiphyseal region is the common
site for GCTB development, however, other frequent regions may occur as
the distal femur, proximal tibia, distal radius and sacrum, rarely
reported in the bones of the head, some reports of bones developing from
endochondral ossification, such as sphenoid, ethmoid and temporal bone,
are almost exclusively involved [3]. In the gnathic bones, the
clinical appearance may vary, causing since dental root resorption to
bone destruction, pain, pathologic fractures and metastatic spread
[4]
It has a clinically aggressive behavior, with a fast growth, sometimes
in weeks, however has few symptoms, leading to thinning and rupture of
bone cortical, invasion of adjacent soft tissues, but not invading or
ulcerating skin and subcutaneous tissue [5]. Albeit the GCTB belongs
to the category of benign tumors, some studies prefer to characterize it
as having “intermediate malignant potential” due to osteolytic
properties causing invasion and destruction of adjacent structures
[5].
The treatment for GCTB also may vary, depending on the aggressiveness of
the tumor. Surgical resection, Embolisation, Bisphosphonates, Anti-RANKL
therapy, Chemotherapy and Radiotherapy can be used4.
Nowadays, the use of Denosumab has gained prominence as an adjuvant
therapy by the inhibitory effects on RANKL, promoting significant
reduction in tumor size, restoration of bone stock, and significant pain
reduction in treated patients [6]
A comprehensive study of differential diagnosis should include tumors
with similar histological appearance as well as benign or malign
epithelial neoplasms with common chronic inflammatory conditions in the
gnathic bones, nasal cavity and paranasal sinuses, such as brown tumor
of hyperparathyroidism, malignant fibrous histiocytoma, giant cell
central granuloma and chronic inflammatory masses from nasal cavity
[7,8]
In this context, we aimed to
present a singular rare clinical case of GCTB in the right maxillary
sinus extending to the nasal cavity and skull base, implicated in a
process coincidentally or casually with another type of lesion primarily
developed.