Auto-Fluorescence and Histopathologic Evaluation of Medication-Related Osteonecrosis of the Jaws: Perspectives for Treatment.

Auto-fluorescence (AF) of healthy bone tissue has recently been described. Loss of AF (LAF) has, on the contrary, been reported in necrotic bone. Further, the use of LAF as a possible guidance to distinguish viable from necrotic bone during surgical treatment of osteonecrosis has been proposed. The aim of this study is to detail 8 patients of medication-related osteonecrosis of the jaws treated through an AF-guided surgical resection. The authors also provide the histopathologic description of hypo-fluorescent and hyper-fluorescent bone in each patient. After removal of necrotic bone block, Er:YAG laser was used for vaporizing further necrotic bone, up to the detection of strongly hyper-fluorescent bone. Samples of hyper-fluorescent bone were collected around areas of necrosis. Histopathologic evaluation revealed viable bone tissue in all hyper-fluorescent specimens. On the basis of these data, AF-guided surgical resection could be effective in highlighting surgical margins of necrotic bone tissue and it might have some utility in a range of applications of bone surgery.

Thyroid cancer incidence by histological type and related variants in a mildly iodine-deficient area of Northern Italy, 1998 to 2009.

BACKGROUND: The incidence of thyroid cancer is increasing in several countries. However, the issue of whether this applies to all different histological types and related variants is poorly addressed. METHODS: All incident thyroid cancers diagnosed between 1998 and 2009 in a mildly iodine-deficient area in northern Italy were derived from a population-based tumor registry. Stage of disease, size of the tumor, focality, and histological variants were recorded from a review of pathology reports and slides. The mean annual increase (MAI) of the standardized incidence rate was calculated over the entire 12-year period of observation and a standardized rate ratio was evaluated to compare the mean standardized incidence between 2 periods of 6 years each (1998-2003 vs 2004-2009). RESULTS: In total, 980 cases were considered. An increase in the incidence trend for all thyroid tumors was demonstrated; the increase was found to be continuous from 1998 to 2002 but not afterward. The cancer incidence increased in both male and female subjects. Papillary thyroid carcinoma (PTC), the follicular variant of PTC, the tall cell variant of PTC (TCV-PTC), and Hurthle cell carcinoma (HC) showed the most relevant changes in incidence whereas follicular carcinoma was not found to be significantly affected. TCV-PTC was the only histological type to demonstrated a significant (P < .01) proportional increase in the second 6-year period of observation. Only TCV-PTC and HC were found to display a significant MAI after 2002. CONCLUSIONS: The incidence of thyroid cancer has increased within the last decade, an increase that is accounted for mostly by differentiated tumors. The most significant increases were documented for aggressive variants of basic histotypes.

Mandibular metastasis from carcinoma of the bladder: Report of a case and literature review.

Metastases represent about 1% of all malignant tumors of the oral region. Only 12 cases of metastases to the jawbones and 3 to the oral soft tissues from a carcinoma of the bladder are reported in the English literature. Here we report a case of an 86 year-old man with a metastasis to the anterior region of the lower jaw from a transitional cell carcinoma of the bladder treated 5 years before, all-together with a literature review. Key words:Bladder, mandibular metastasis, oral metastasis, transitional cell carcinoma.

Abscopal effect as part of treatment of oligometastatic head and neck cancer: A case report.

A 66-year-old man with hypopharyngeal carcinoma with a single bone metastasis was treated with definitive chemo/radiotherapy omitting local treatment of the single bone lesion. He remained relapse-free for 6 years. We have concluded that radiotherapy-dependent abscopal effect might have allowed to avoid ablative treatment of metastatic site.

Molecular Profiling of Clear Cell Myoepithelial Carcinoma of Salivary Glands With EWSR1 Rearrangement Identifies Frequent PLAG1 Gene Fusions But No EWSR1 Fusion Transcripts.

Myoepithelial carcinoma of salivary glands is an underrecognized and challenging entity with a broad morphologic spectrum, including an EWSR1-rearranged clear cell variant. Myoepithelial carcinoma is generally aggressive with largely unknown genetic features. A retrospective review of Salivary Gland Tumor Registry in Pilsen searching for the key words "clear cell myoepithelial carcinoma," "hyalinizing clear cell," and "clear cell malignant myoepithelioma" yielded 94 clear cell myoepithelial carcinomas (CCMCs) for molecular analysis of EWSR1 rearrangement using fluorescence in situ hybridization (FISH). Tumors positive for EWSR1 gene rearrangement were tested by next-generation sequencing (NGS) using fusion-detecting panels. NGS results were confirmed by reverse-transcription polymerase chain reaction or by FISH. Twenty-six tumors originally diagnosed as CCMC (26/94, 27.6%) revealed split signals for EWSR1 by FISH. Six of these tumors (6/26, 23%) displayed amplification of the EWSR1 locus. Fifteen cases were analyzable by NGS, whereas 9 were not, and tissue was not available in 2 cases. None of the CCMCs with EWSR1 rearrangements detected by FISH had an EWSR1 fusion transcript. Fusion transcripts were detected in 6 cases (6/15, 40%), including LIFR-PLAG1 and CTNNB1-PLAG1, in 2 cases each, and CHCHD7-PLAG1 and EWSR1-ATF1 fusions were identified in 1 case each. Seven cases, including those with PLAG1 fusion, were positive for PLAG1 rearrangement by FISH, with notable exception of CHCHD7-PLAG1, which is an inversion not detectable by FISH. One single case with EWSR1-ATF1 fusion in NGS showed ATF1 gene rearrangement by FISH and was reclassified as clear cell carcinoma (CCC). In addition, another 4 cases revealed ATF1 rearrangement by FISH and were reclassified as CCC as well. Moreover, 12/68 (17%) CCMCs with intact EWSR1 gene were selected randomly and analyzed by NGS. PLAG1 fusions were found in 5 cases (5/12, 41.6%) with LIFR (2 cases), FGFR1 (2 cases), and CTNNB1 (1 case) as partner genes. Overall, PLAG1 gene rearrangements were detected in 10/38 (26%) tested cases. None of the tumors had SMARCB1 loss by immunohistochemistry as a possible explanation for the EWSR1 abnormalities in FISH. Novel findings in our NGS study suggest that EWSR1-FISH positive CCMC is a gene fusion-driven disease with frequent oncogenic PLAG1 fusions, including LIFR-PLAG1 and CTNNB1-PLAG1 in most cases. Productive EWSR1 fusions are found only in a minority of EWSR1-ATF1-rearranged cases, which were in part reclassifiable as CCCs. Detectable EWSR1-FISH abnormality in CCMCs without gene fusion perhaps represents a passenger mutation with minor or no oncologic effect.

Nd:YAG laser versus traditional scalpel. A preliminary histological analysis of specimens from the human oral mucosa.

Hyperplastic fibro-epithelial lesions are the most common tumor-like swellings in the mouth. The neodymium yttrium aluminium garnet (Nd:YAG) laser appears to be useful for the surgical treatment of these lesions. Some controversies of laser surgery concern the accuracy of pathological diagnosis as well as the control of thermal damage on the target tissue. The aim of this study was to establish if the thermal changes induced by the Nd:YAG laser may affect the histopathological diagnosis and the evaluation of the resection margins. Furthermore, we compared the histological features of oral benign fibro-epithelial lesions excised through Nd:YAG laser and traditional scalpel. Twenty-six benign fibro-epithelial oral lesions from 26 patients, localized in the same oral subsites (cheek and buccal mucosa), were collected at the Unit of Oral Pathology and Oral Laser-assisted Surgery of the Academic Hospital of the University of Parma, Italy. Specimens were subclassified into three groups according to the tool used for the surgical excision. Group 1 included six specimens excised through Nd:YAG laser with an output power of 3.5 W and a frequency of 60 Hz (power density 488,281 W/cm2); Group 2 included nine specimens excised through Nd:YAG laser with an output power of 5 W and a frequency of 30 Hz; Group 3 included 11 specimens excised through a Bard-Parker scalpel blade no. 15c. Epithelial changes, connective tissue modifications, presence of vascular modifications, incision morphology and the overall width of tissue modification were evaluated. Differences between specimens removed with two different parameters of Nd:YAG laser were not significant with regard to stromal changes (p=0.4828) and vascular stasis (p=0.2104). Analysis of regularity of incision revealed a difference which was not statistically significant (p=1.000) between group 1 and group 2. Epithelial and stromal changes were significantly more frequent in specimens with a mean size less than 7 mm (p<0.0001). Nd:YAG laser induced serious thermal effects in small specimens (mean size less than 7 mm) independently from the frequency and power employed. The quality of incision was better and the width of overall tissue injuries was less in the specimens obtained with higher frequency and lower power (group 1: Nd:YAG laser at 3.5 W and 60 Hz).

Mastoid Dermoid Cyst.

A case of mastoid dermoid cyst (DC) was presented, and differences with cases of other temporal bone DCs were analyzed. The mastoid DC was also compared with mastoid congenital cholesteatoma. We reported a case of a patient with mastoid DC, evaluating her clinical, radiological, and surgical findings. A review of the literature was performed to compare our findings with those reported. The preoperative radiological evaluation prompted us to plan a surgical approach to the lesion, suspecting the presence of a mastoid congenital cholesteatoma. The surgical findings were in line with the presence of a mastoid DC. Only two cases reported in the literature presented features that fulfilled the criteria of a true mastoid DC. A DC confined to the mastoid region is an extremely rare clinical entity, with asymptomatic and slow growth. Preoperative radiological differentiation between congenital cholesteatoma and DCs with atypical features can be difficult. However, surgical excision is the treatment of choice in both cases. Diagnosis is confirmed by the histological evaluation.

Large-sized pleomorphic adenoma of the cheek treated with Nd:Yag laser: report of a case and review of the literature.

Pleomorphic adenoma (PA) mostly involves parotid glands, while extra-parotid localizations are relatively uncommon. Particularly, PAs of the cheek minor salivary glands with a size larger than 4 cm are exceedingly rare, with only few cases reported. Surgical treatment of PA usually consists in radical excision. However, despite a presumptive radicality, recurrences, sometimes followed by malignant transformation, may occur. Here we report a case of a large-sized (6 cm) PA of the cheek minor salivary glands in a 70 year-old female patient, successfully treated through a conservative approach, based on the use of Nd:YAG Laser (λ=1064 nm). No recurrences were observed after a 2-year follow-up. A concise review of the literature, describing the features of 14 cases is also provided. Advantages of laser treatment include a precise cut, reduction of trauma on surrounding tissues, the possibility of a very good intraoperative hemostasis. Such features may sometimes allow to avoid general anesthesia, even for removal of big lesions. Post-operative course, in terms of pain and swelling, is usually better for intervention performed with laser, when compared to traditional surgery. Key words:Oral surgery, oral pathology, pleomorphic adenoma, laser surgery, minor salivary glands, salivary glands tumors.

A Single Case Report of Granular Cell Tumor of the Tongue Successfully Treated through 445 nm Diode Laser.

Oral granular cell tumor (GCT) is a relatively rare, benign lesion that can easily be misdiagnosed. Particularly, the presence of pseudoepitheliomatous hyperplasia might, in some cases, lead to the hypothesis of squamous cell carcinoma. Surgical excision is the treatment of choice. Recurrence has been reported in up to 15% of cases treated with conventional surgery. Here, we reported a case of GCT of the tongue in a young female patient, which was successfully treated through 445 nm diode laser excision. Laser surgery might reduce bleeding and postoperative pain and may be associated with more rapid healing. Particularly, the vaporization effect on remnant tissues could eliminate GCT cells on the surgical bed, thus hypothetically leading to a lower rate of recurrence. In the present case, complete healing occurred in 1 week, and no recurrence was observed after 6 months. Laser surgery also allows the possibility to obtain second intention healing. Possible laser-induced histopathological artifacts should be carefully considered.

Molecular Profiling of Salivary Oncocytic Mucoepidermoid Carcinomas Helps to Resolve Differential Diagnostic Dilemma With Low-grade Oncocytic Lesions.

Oncocytic mucoepidermoid carcinoma (OMEC) is a rare but diagnostically challenging variant of mucoepidermoid carcinoma (MEC). OMEC is notable for differential diagnostic considerations that are raised as a result of overlap with other benign and low-grade oncocytic salivary gland tumors. Diffuse and strong immunoreactivity of p63 protein may be useful in distinguishing OMEC from its mimics. However, focal p63 staining can be present in benign oncytomas. Presence of mucin-containing cells, mucinous cystic formation, and foci of extravasated mucin are considered a hallmark of MEC. True mucocytes may be, however, very few and hardly discernable in OMECs. Recent evidence has shown that most MECs harbor gene fusions involving MAML2. A retrospective review of archived pathology files and the authors' own files was conducted to search for "low-grade/uncertain oncocytic tumor," "oncocytoma," and "oncocytic carcinoma" in the period from 1996 to 2019. The tumors with IHC positivity for p63 and/or p40, and S100 negativity, irrespective of mucicarmine staining, were tested by next-generation sequencing using fusion-detecting panels to detect MAML2 gene rearrangements. Two index cases from consultation practice (A.S. and A.A.) of purely oncocytic low-grade neoplasms without discernible mucinous cells showed a CRTC1-MAML2 fusion using next-generation sequencing, and were reclassified as OMEC. In total, 22 cases of oncocytic tumors, retrieved from the authors' files, and from the Salivary Gland Tumor Registry, harbored the MAML2 gene rearrangements. Presence of mucocytes, the patterns of p63 and SOX10 immunopositivity, and mucicarmine staining were inconsistent findings. Distinguishing OMEC devoid of true mucinous cells from oncocytoma can be very challenging, but it is critical for proper clinical management. Diffuse and strong positivity for p63 and visualization of hidden mucocytes by mucicarmine staining may be misleading and does not always suffice for correct diagnosis. Our experience suggests that ancillary studies for the detection of MAML2 rearrangement may provide useful evidence in difficult cases.

Correlation between cytological and histological findings in patients who underwent thyroidectomy. Predictive value and confounders.

BACKGROUND: Solitary thyroid nodules are the most common endocrine occurance in general population. With the introduction of Bethesda system for reporting thyroid cytopathology (BSRTC) to fine-needle aspiration (FNA) specimens we found a reliable standard method to evaluate malignancy risk in thyroid neoplasms. This study evaluates the correlation between BSRTC and real results in our center investigating the role of several factors as confounding factors for cytological diagnosis. The study has been designed as a retrospective study conducted on 637 patients that underwent thyroid surgery in a single center (Unit of General Surgery, Parma University Hospital, Italy). METHODS: We reviewed 637 files of patients who underwent thyroid surgery with a definitive histological finding from surgical specimen. The collected data include: cytological findings from FNA when performed, histological findings after surgery, sex, age, thyroid hyperfunction and the possible presence of thyroiditis. Cytological findings have been evaluated from our institution's pathologists after FNA performed in collaboration with clinical endocrinologists. Thyroid Hyperfunction has been evaluated through a blood test panel for thyroid functionality including reflex TSH, FT3, FT4 and thyreoglobulin. Blood tests' results and patients have been evaluated by clinical endocrinologists before being addressed to surgery. Thyroiditis have been confirmed as an ultrasound scanning (US) finding or as a corollary from histologic results. All patients have been evaluated by the surgeon and underwent different intervention as total, thyroidectomy, near total thyroidectomy or emithyroidectomy depending on cythology, US findings and symptoms in case of benignancy. Histological findings have been evaluated only by our center pathologists. RESULTS: In our experience the percentage of malignancy in Thyr 2 Thyr 3 and Thyr 4 Bethesda's classes seeems to be higher then those predicted by BSRTC. We also found a high rate of false positive considered as patients included in categories of suspected malignancy (Thyr 3-4-5-6) and subsequently resulted with benign pathology. This happens specially in those patients affected by thyroiditis. CONCLUSIONS: These findings suggest that we need more studies to evaluate real BSRTC predictive value in single centers. Meanwhile we found out that thyroiditis may be a confounding factor in cytological examination wich would lead to an overstating of thyroid nodules.

Primary Epithelioid Angiosarcoma of the Thyroid in a Patient Occupationally Exposed to Radiations.

Background: Angiosarcoma (AS) of the thyroid is a rare and aggressive tumor. Its incidence is higher in iodine-deficient areas but cases unrelated to endemic goiter have been reported. Case Presentation: We describe a case of a 63-year-old Italian man living in a non-iodine-deficient area, with no previous diagnosis of thyroid disease with a history of radiation exposure. The patient-an interventional cardiologist who had worked for 15 years in an angiographic room- came to the clinical observation because of the rapid onset of dyspnea and dysphonia. Computed tomography (CT) showed a 13-cm inhomogeneous neck mass, originating from the left thyroid lobe which caused displacement and stenosis of the trachea. The patient underwent diagnostic fine-needle aspiration that was followed by total thyroidectomy and lymphadenectomy of central and left lateral cervical nodes. The final pathological diagnosis was epithelioid angiosarcoma (EAS), high grade. The preoperative staging by CT of the head, neck, abdomen, chest and pelvis was negative. At pathological staging, the tumor was angionvasive but it was limited to the thyroid; no lymphnode metastases were detected. Chemotherapy with Epirubicin and Ifosfamide was administered for 4 cycles and, then, it was discontinued due to significant bone marrow toxicity. Conclusion: One year after diagnosis, the CT of neck, abdomen, chest, and pelvis were negative. At 2 years after diagnosis, the FDG-PET was negative with no evidence of the disease at CT Due to the known association between the occurrence of angiosarcoma after radiation therapy it is tempting to speculate that in this patient the presence of thyroid EAS may be linked to radiation exposure.The patient is still alive at 62 months after diagnosis. He is on a follow-up program by a 6-month /1-year neck, chest, abdomen, and pelvis CT evaluation with no signs of metastases.

Unusual presentation of primary squamous cell carcinoma involving the interdental papilla in a young woman.

A 33-year-old woman presented with what looked like an epulis at the interdental papilla between 22 and 23. We excised the lesion and histopathological examination surprisingly showed the presence of a well-differentiated squamous cell carcinoma that was not invading the underlying bone. We then did a radical excision including extraction of teeth followed by bony reconstruction. No recurrence or metastases have been seen during a follow-up of 12 months.

A rare case of thyroid haemangiosarcoma.

The incidence of haemangiosarcoma in the literature is variable especially in the Alpine region and in Austria, ranging from 2 to 10% of all thyroid neoplastic lesions. This thyroid disease is characterised by positive endothelial markers (CD 31, CD 34 and FVIII), and co-positive markers for cytokeratins, epithelial membrane antigen and a loss of thyroglobulin can sometimes be found. Immunochemistry does not help the physician to classify the neoplasia as a variant of anaplastic carcinoma or sarcoma of endothelial origin. We present a case of epithelioid haemangiosarcoma in an elderly woman from outside the Alpine region with a contralateral papillary cancer treated by total thyroidectomy. The prognosis is poor and case reports are rare.

Size of thyroid carcinoma by histotype and variants: A population-based study in a mildly iodine-deficient area.

BACKGROUND: Data relating the size of thyroid cancer with histological types and variants are scarce. METHODS: All incident thyroid cancer diagnosed between 2003 and 2012 in a mildly iodine-deficient area were derived from a population-based tumor registry. Undifferentiated/anaplastic thyroid cancer and incidental cases were excluded. Major diameter of thyroid cancer, as assessed by pathological examination, was stratified in classes: ≤10 mm; 11-20 mm; 21-40 mm; and >40 mm. For each class, absolute and relative frequencies of histological types were calculated. RESULTS: Tumors >20 mm were more frequent among follicular thyroid carcinoma (FTC) and Hürthle cell carcinoma than in other histotypes, with median size of 22.50 mm (95% confidence interval [CI] 16.71-28.29) and 25.00 mm (95% CI 17.04-32.96) in FTC and Hürthle cell carcinoma, respectively. Odds ratio for tumors >20 mm was significant for FTC and Hürthle cell carcinoma only (P < .0001). CONCLUSION: Among the histotypes and variants of differentiated thyroid cancer, FTC and Hürthle cell carcinoma are characterized by the largest size.

Thyroid micro-carcinoma: only a diagnostic epidemic?

BACKGROUND: The incidence of thyroid carcinoma ranges from 0.5 to 10 cases every 100,000, depending on the country, the context and purpose of the study. The high incidence of differentiated thyroid tumor is continuously growing. While most malignant pathologies affect the adults, a proportion of 1-2% of pediatric population is affected by solitary nodule, of which some are malignant cancers. Studying thyroid malignant cancer, the most sensitive and accurate imaging technique is color Doppler ultrasonography. Fine needle aspiration cytology (FNAC), if correctly performed, is the key to a correct diagnosis. METHODS: This prospective study analyzes 1726 cases of total thyroidectomy and lobectomy performed between January 2004 and December 2013. The cytology sampling has been done following standard FNAC or capillary aspiration. Results have been classified in five classes, following the Italian SIAPEC-AIT system (2008). Sensibility, specificity, accuracy, negative predictive value and positive for the evaluation of FNAC technique are the statistical parameters considered. RESULTS: The outcome is aligned with what already known in literature, that FNAC has sensibility between 60-98% and specificity between 72-100%. Considering Tir3 as a low malignancy risk category therefore not suitable for surgery, those values decrease. CONCLUSIONS: Micro-carcinoma is a more represented entity than apparently suspected. Nowadays, cytology is the most precise diagnostic support to the therapeutic management of thyroid node, yet it is still charged with false negatives. The evaluation of data records, combined with some molecular biology techniques and applied to cytology, could help in giving more appropriate surgical indication, allowing the surgery to be therapeutic more than diagnostic.

Estrogen receptor (ER)-beta, but not ER-alpha, is present in thyroid vessels: immunohistochemical evaluations in multinodular goiter and papillary thyroid carcinoma.

OBJECTIVE: Estrogen receptors (ERs) have been demostrated in the vessel structures of several systems. Little is known on the presence of ERs in the thyroid vessels. DESIGN: We immunohistochemically evaluated both ER-alpha and ER-beta immunoreactivity (IR) in both vascular and follicular thyroid cells in tissue samples from 17 cases of multinodular goiter (MNG) and 17 cases of papillary thyroid carcinoma (PTC). MAIN OUTCOME: ER-alpha IR was undetectable in either tissue examined. In 100% of MNG samples, nuclear ER-beta IR was detected in both endothelial and follicular cells. In PTC samples, endothelial nuclear ER-beta IR was found in 100% of cases, whereas the nuclear staining of follicular cells was found in 83% of cases. The intensity of staining of the endothelial ER-beta IR was comparable between MNG and PTC. However, when follicular cells were considered, a tendency toward a decrease in nuclear staining and a significant increase in cytoplasmic staining were found in PTC lesions as compared to MNG. CONCLUSIONS: This study demonstrated that ER-beta, but not ER-alpha, IR is present in the endothelium of thyroid vessels. Furthermore, although data need to be confirmed in larger observations, these results suggest the lack of differences in the pattern of vascular ER-beta IR between MNG and PTC.

Bone necrosis of the jaws associated with bisphosphonate treatment: a report of twenty-nine cases.

Bone necrosis of the jaws is often related to head and neck radiotherapy, to surgical procedures at maxillary or mandibular level but also to various local and systemic factors such as haematological diseases, haemoglobinopathies and systemic lupus eritematosus; its pathogenesis maybe associated with defects of vascularization. Bisphosphonate are synthetic analogues of pyrophosphate used for the treatment of hypercalcemia in patients with malignancies and bone metastasis and for the treatment of many other disorders such as metabolic bone diseases, Paget's disease, and osteoporosis; their pharmacological activity is related to the inhibition of the osteoclastic function which leads to resorption and reduction of bone vascularization. Since the end of 2003 Bisphosphonate-associated Osteonecrosis (BON) has become an increasing problem and the test of that is the increase of the relative published case report and case series. Here we report 29 cases of bone necrosis of the jaws in patients treated with pamidronate (Aredia), zoledronate (Zometa) and alendronate: 15 underwent surgical procedures and 14 occurred spontaneously. Among these patients (21 females, 8 males; mean age between 45 and 83 years); 14 were treated for bone metastasis, 12 for multiple myeloma and 3 for osteoporosis. Bone necrosis involved only maxilla in 7 patients, only mandible in 20 patients and both in 2 patients. Six patients had multiple osteonecrotic lesions, 3 contemporary lesions and 3 non contemporary. In these patients we performed 3 kinds of therapy, associated or not: medical therapy (with antibiotic drugs, antimycotics and antiseptic mouthwashes), surgical therapy with curettage or sequestrectomy and Nd:YAG laser biostimulation.

Peripheral ossifying fibroma: A clinicopathologic study of 27 cases and review of the literature with emphasis on histomorphologic features.

The peripheral ossifying fibroma (POF) is a relatively uncommon, reactive gingival overgrowth usually composed of cellular fibroblastic tissue containing one or more mineralized tissues, namely bone, cementum-like material, or dystrophic calcification. The aetiology and pathogenesis of POF are yet not clear, but some authors have hypothesized a reaction originating from the periodontal ligament, as a result of irritating agents such as dental calculus, plaque, orthodontic appliances, and ill-fitting restorations. The aim of our study was to report the clinicopathologic features of a case series of POF from a single Italian institution. A total of 27 cases were collected over an 18-year period. Detailed relevant medical history, clinical and histological information were recorded for each patient. The age range of patients (m = 6; f = 21) was 17.2-80.1 years with a mean of 42.9 ± 18.1 years. Occurrence of the lesion in the mandibular and maxillary arches was similar, and 67.0% occurred in the incisor-cuspid region. The lesions ranged in size from 0.3 to 5.0 cm (mean, 1.3 cm ± 1.1 cm). All the different types of mineralization were present, with higher prevalence of lamellar bone. The lesions were treated by surgical excision and four lesions in three patients recurred after surgery. Surgeons should consider the high recurrence rate of POF and remove the lesion down to the bone involving also the adjacent periosteum and the periodontal ligament. Professional prophylaxis should precede any surgical procedure, and periodical dental hygiene recalls are important in order to remove any possible irritating factor.