DISCUSSION
The WHO classification of tumors define the GCTB as a primary intra-medullary bone tumor composed of mononucleated cells and osteoclast-like multinucleated giant cells and presenting as a locally aggressive lesion with unpredictable behavior [7]. It is believed that the stroma represents the active portion of the tumor cells, capable to secreting differentiation factors that recruit monocytes, promoting their fusion and forming the third cell type in CGTB, the osteoclastic-like multinucleated giant cells [7].
For any benign or malignant pathological process, the stroma plays a fundamental role in its development, composed of proteoglycans, glycoproteins and water. In the GCTB, cytokines and differential factors including MCP1, ODF and M-CSF are present, suggesting that these molecules are essential to genesis of osteoclastic-like multinucleated giant cells [8]. However, several chronic inflammatory lesions with giant cell configuration may have similar histopathologic features, principally in its beginning. In our case, the primarily lesion developed 4 years ago, have shown already the positivity of CD68 marker and low activity of multinucleated giant cells in between, however, we believed that the size of the incisional biopsy performed previously could have compromised the global assessment of the lesion, omitting important characteristics of its development. Furthermore, there is a possibility that this tumor may represent a giant cell tumor of the bone arising ectopically placed in this region. Although we cannot exclude this hypothesis we do not have support to affirm this.
The WHO describe the histological appearance of GCTB as a highly cellular lesion typically dominated by large numbers of non-neoplastic osteoclast-like giant cells, between which mononuclear cells are embedded. The giant cells have a variable number of nuclei, some with > 50 per cell. Mononuclear cells in GCTB exhibit a variety of morphological appearances, including round to oval cells in a fibrotic background and spindle cells associated with fibrous matrix. The presence of atypical mitotic figures should raise suspicion for malignancy. In the present case, it was observed this large number of multinucleated giant cells in all analyzed fields, some with > 20 nuclei per cell. Also, the cytoplasm of the mononuclear cells was pattern epithelioid with nuclei similar to seen in multinucleated giant cells. The stroma was fibrous with spindle cells associated. However, atypical mitotic figures were not evident in this case. Furthermore, some areas contain hemorrhage focus and large number of xanthoma cells having abundant cytoplasm with fine vacuoles, which was also reported by other previous studies [1,4,5,9].
Occasional Touton giant cells were noted in this case. Kumar et al. [10] analyzed 68 cases of GCTB of the tendon sheath. These 68 cases, osteoclastic-like giant cells were uniformly seen in all cases, while only nine (13.2%) cases in addition showed Touton-type giant cells, which confirms that this finding is not a common feature in these tumors [10]. According Amary F. et al. the anti-histone H3.3 G34W Rabbit monoclonal antibody (clone RM263) is highly specific and sensitive for tumors and a powerful immunohistochemical marker for GCTB, improving the final diagnosis and biopsy specimens, allowing also, distinguishing GCTB from its mimics, like giant cell granulomas of the jaw, cherubism, brown tumors of hyperparathyroidism and foreign body-type giant cell reaction [11].
The management treatment for GCTB tumors depends on their location and radiological features. Surgical resection is the universal standard for treatment of GCTB [12]. Currently, the Denosumab is used as an adjuvant for causing suppression of osteoclastic lineage cells and preventing bone destruction [12]. Nevertheless, studies comparing different treatment methods with Denosumab has shown an increase rate of recurrence (20% to 100%) using curettage with preoperative denosumab comparing to curettage-alone group (0% to 50%) [13]. This different result, related with long-term therapeutic effect of denosumab, may cause dramatic changes in the tumor’s histologic appearance, not eradicating mutational status of H3F3A and H3F3B, however careful evaluation is necessary for its use [14].
In summary, the association of the GCTB and the previous Polypoid mass was exceptionally uncommon and extremely rare. In our patient the first lesion occurred 4 years ago, with no signs of malignity or complication such as metastasis or spread and just incisional biopsy was made. The second lesion (GCTB) appeared as a silent event, gradually led to the development of a slow-growing lesion that was difficult to diagnose until it externalized through the right nasal cavity and is perceived by the patient. Although these conditions may occur coincidentally, rather than causally, we had to consider the possibility that these two entities were associated in our patient; we agree that possibly there was a relationship between the activity of the remaining polypoid tissue in the nasal cavity and the GCTB in all maxillary sinus. We do not have support to affirm that the first lesion become GCTB, certainly more control studies are needed for this.
To the best of our knowledge, there is only this report in the literature that describes a case with both GCTB and Polypoid tissue developed in the same location and in the head and neck region. Thus, we suggest to reach the diagnosis of GCTB and Polypoid tissue the combined use of Computed Tomography, Nuclear Magnetic Resonance, Histopathology, Immunohistochemistry, Blood Complementary Test, Bone Scintigraphy and Angiography depending on location, aggressiveness and size of lesion. Due to the fact that the patient is located in another city and does not have many financial conditions, we were not able to investigate in detail the possibly association of injuries. In addition, the public hospital where the clinical case was carried out lacks the resources to offer all these tests.