The impact of histopathological criteria for definite vasculitis in giant cell arteritis: retrospective analysis of temporal artery biopsies.

Histopathological findings associated with definite vasculitis in temporal artery biopsy (TAB) defined in 2022 ACR/EULAR classification criteria for Giant Cell Arteritis (GCA) was published in 2022. We aimed to evaluate the TAB of our GCA patients for histopathological findings associated with definite vasculitis. Patients who were diagnosed with GCA by clinicians and underwent TAB between January 2012 and May 2022 were included. Hospital electronic records and patients' files were reviewed retrospectively. A total of 90 patients' pathology reports were evaluated by a pathologist and a rheumatologist. In cases where microscopic findings were not specified in the pathology reports, histopathologic specimens were re-evaluated (n = 36). A standard checklist was used for histopathological findings of definite vasculitis. Patients were divided into two groups; (i) definite vasculitis-GCA and (ii) non-definite-GCA group, and the clinical and demographic characteristics for all patients were compared. The mean age of patients was 69.8 (± 8.5) years and 52.2% were female. In the first evaluation, 66 (73.3%) patients had a diagnosis of vasculitis according to pathology reports. In the re-evaluation of biopsy specimens, at least one definite finding of vasculitis was observed in TAB of 10/24 (41.6%) patients whose microscopic findings were not specified in the pathology reports. The ROC analysis showed that biopsy length had diagnostic value in predicting the diagnosis of definite vasculitis (AUC: 0.778, 95% CI: 0.65-0.89, p < 0.001). In those with a biopsy length of ≥ 1 cm, sensitivity was 76.5%, specificity was 64.3%, and PPV value was 92. In multivariate analysis, the most significant factor associated with definite vasculitis was biopsy length (OR: 1.18 (1.06-1.31), p = 0.002). Microscopic findings were reported in over 70% of patients. Reinterpretation of results according to a standard check-list improved the impact of TAB in the diagnosis of GCA. A biopsy length ≥ 1 cm was found to contribute towards a definitive histopathological vasculitis diagnosis.

A pulmonary mass extending into the left atrium through the pulmonary vein: a rare diagnosis with an unusual origin.

INTRODUCTION: Myxofibrosarcoma usually occurs in the extremities of middle-aged to older adults. Metastatic myxofibrosarcomas generally emerge in the lung. In this case report, we aim to present a case of primary pulmonary myxofibrosarcoma with tumor thrombus extending into the left atrium without pulmonary vein or atrial invasion. CASE PRESENTATION: A 55-year-old male who was being followed up due to a pulmonary nodule presented with a mass extending from the left lower lobe to the left atrium. No extrathoracic malignancy was detected in the pre-operative examination. The mass extending into the left atrium without invasion was excised with the lower lobe of the left lung. A post-operative histopathological examination revealed myxofibrosarcoma. CONCLUSION: Very few cases of cervical, thoracic wall, mediastinum and cardiac primary myxofibrosarcoma have been documented, and to the best of our knowledge, only one primary pulmonary myxofibrosarcoma case has previously been reported in the English literature. Here, we present a case of primary pulmonary myxofibrosarcoma that extended to the left atrium through the pulmonary vein. In such rare clinical presentations, intracardiac tumor resection should precede pulmonary resection due to the possibility of catastrophic tumor embolisms.

Kindlin-3 and RASSF6 are probable biomarkers for predicting metastasis in cutaneous melanoma.

It is well known that metastasis is the most crucial factor in determining the fate of the patient. The prognosis of melanoma is very poor at the stage of metastasis. Recently, several genes and proteins, including kindlin3, dioxin receptor (AhR), RASSF6, and claudin-11, which were shown as possible prognostic biomarkers for human tumours, were described. In this study, we focused on these proteins in melanoma within a clinical setting. Forty-three primary melanomas (PMs), 17 metastatic melanomas (MMs), 15 melanocytic nevi (MN), and two melanoma cell lines were included in this retrospective study. All proteins were investigated using immunohistochemistry, and analysis was performed using a semi-quantitative immunoreactive score (IRS). The nevus group showed lower RASSF6 and AhR IRS levels than PMs. RASSF6 and kindlin-3 levels in the PMs with metastasis (MwM) and also in PMs showing lymphovascular invasion were significantly lower. The logistic regression model also proved that kindlin-3 expression was a significant independent predictor of metastasis. The current study supports the role of kindlin-3 and RASSF6 as prognostic biomarkers in melanoma. Besides the prognostic roles of these proteins, they are probably potential candidates for target-oriented therapies for melanoma metastasis blocking.

Expression of Sigma-Class Glutathione-S-Transferase in Fetal and Pediatric Filum Terminale Samples: A Comparative Study.

Background and objectives: The pathophysiology of tethered cord syndrome (TCS) in children is not well elucidated. An inelastic filum terminale (FT) is the main factor underlying the stretching of the spinal cord in TCS. Our study aimed to investigate the expression of glutathione-S-transferase (GST) in children and fetal FT samples in order to understand the relationship between this enzyme expression and the development of TCS. Materials and Methods: FT samples were obtained from ten children with TCS (Group 1) and histological and immunohistochemical examinations were performed. For comparison, FT samples from fifteen normal human fetuses (Group 2) were also analyzed using the same techniques. Statistical comparison was made using a Chi-square test. Results: Positive GST-sigma expression was detected in eight (80%) of 10 samples in Group 1. The positive GST-sigma expression was less frequent in nine (60%) of 15 samples from Group 2. No statistically significant difference was detected between the two groups (p = 0.197). Conclusions: Decreased FT elasticity in TCS may be associated with increased GST expression in FT. More prospective studies are needed to clarify the mechanism of the GST-TCS relationship in children.

Primary ovarian fibrosarcoma: a case report and review of the literature.

OBJECTIVES: Primary ovarian fibrosarcomas are extremely rare neoplasms, and only 50 cases have been reported in the English literature. Diagnosis can be difficult because of this condition's rarity, and other similar appearing mesenchymal lesions should be ruled out. METHODS: A 50-year-old postmenopausal woman came to our hospital because of abdominopelvic pain. Ultrasonography revealed a 41x33 mm heterogeneous solid mass in the right ovary. Total blood counts, biochemical parameters, and tumor markers were within normal ranges. Total abdominal hysterectomy, and bilateral salpingo oophorectomy were performed. Examination of a frozen, specimen revealed fibroma; however, the final histopathological diagnosis was low grade fibrosarcoma of the ovary. Microscopic examination demonstrated densely cellular, spindle-shaped tumor cells with increased mitotic activity (5 to 6 mitoses per 10 high-power fields). RESULTS: Immunohistochemical analysis revealed that the tumor cells were positive for vimentin and negative for actin and desmin and that the Ki 67 proliferation index was 30% to 40%. The patient did not receive adjuvant treatment, and remained free of disease after a follow up of 6 months. CONCLUSIONS: Although ovarian fibrosarcomas are unusual causes of solid masses in postmenopausal women, they should be considered when adnexal masses are examined in these patients. Mitotic activity and Ki-67 positivity were identified as important diagnostic factors for ovarian fibrosarcoma.

Histological structure of the medial and lateral walls of cavernous sinus in human fetuses.

PURPOSE: The aim of this study is to elucidate the architecture of these fine structures in human fetuses. METHODS: The histological examination of medial wall (MW) and lateral wall (LW) was performed in 15 normal human fetuses. Eleven fetuses were female and four were male. The gestational age ranged between 14 and 35 weeks. The weight ranged between 180 and 1750 g. The wall samples (two MW and two LW from each fetus) were obtained by microsurgical technique and underwent histological examination. Each wall was examined for the structure and composition of collagen and elastic fibers, ganglions, peripheral nerves, and vessels. RESULTS: A total of 60 wall samples (30 MW and 30 LW) were examined in 15 fetuses. Loose connective tissue composed of type III collagen was observed in both of the walls. Elastic fibers were observed only in three wall samples (two MW and one LW). Ganglion was detected in 11 samples (nine in LW and two in MW), and peripheral nerve was found in 28 walls (18 LW and 10 MW). Vessels were observed in 51 samples (26 LW and 25 MW). None of the walls was stained with type I collagen. CONCLUSIONS: The structure of LW and MW of the cavernous sinus (CS) in fetuses is mainly composed of collagen tissue while some elastic fibers are supported by this tissue. Type III collagen is the main component of fetal CS walls. Because of the weak histological structure, CS may be more prone to tumor invasion in infants.

A case of Graham-Little-Piccardi-Lasseur syndrome.

Graham-Little-Piccardi-Lasseur Syndrome (GLPLS) is a variant of lichen planopilaris, which is characterized by progressive cicatricial alopecia of scalp, non-cicatricial alopecia of axillae and pubic regions, and keratosis pilaris-like follicular papules over trunk and extremities. GLPLS is a disease of unknown etiology. However, recent reports support a central role for a T-cell-mediated immune response in the pathogenesis of GLPLS. Besides, although GLPLS is believed to occur sporadically, a genetic predisposition also has been implicated in the pathogenesis. On the other hand, GLPLS typically affects middle-aged women, particularly of the postmenopausal age group. A diagnosis of GLPLS is generally apparent with the presence of characteristic findings in a postmenopausal woman. Herein, we report a case of GLPLS in a 75-year-old woman with the typical triad of alopecia of the scalp, non-cicatricial alopecia of axillae and pubis, and a follicular keratotic eruption on the trunk.

Which treatment method should be preferred for lumbar discal cysts? A case report and a review of the literature.

Discal cysts are extremely rare pathologies that occur most often in the lumbar region. The clinical symptoms of discal cysts are indistinguishable from those of a lumbar disc herniation. The aetiology and pathogenesis of discal cysts remain unknown. The optimal treatment of discal cysts also remains controversial. Most cases of lumbar discal cysts are treated surgically, while some cases regress spontaneously. In this article, we report a case of a lumbar discal cyst treated surgically by microdiscectomy. We discuss the treatment options for discal cysts in the context of the literature.

Osseous metastases of uterine leiomyosarcoma: Analysis of survival & surgical management.

BACKGROUND: Uterine leiomyosarcoma represents a seldom-encountered subset within the spectrum of uterine malignancies. Occurrences of appendicular skeletal metastases in uterine leiomyosarcomas are infrequent. In this study, we examined patient surveys to elucidate the clinical characteristics and outcomes of individuals with uterine leiomyosarcoma exhibiting metastatic dissemination to these anatomical regions. We hypothesized that palliative surgical treatment would have no effect on survival in patients diagnosed with uterine leimyosarcoma with appendicular bone metastases. METHODS: One hundred fourteen patients diagnosed with uterine leiomyosarcoma and treated at the Department of Oncologic Orthopedics at XXX hospital from 2004 to 2021 met the criteria for inclusion in this retrospective cohort study. The study specifically encompassed patients with histopathologically confirmed appendicular bone metastases secondary to uterine leiomyosarcoma, who underwent either surgical intervention or conservative treatment. Exclusion criteria involved patients with exclusive vertebral bone metastases, as well as those lacking essential examination and follow-up data. Notably, the study included nine follow-up patients with at least 2 years of follow-up who developed appendicular skeletal metastases during the follow-up period. RESULTS: Of the 9 patients, 3 had humeral metastases, 2 had femoral metastases, 1 had femoral and diffuse pelvic metastases, and the other 3 had pelvic metastases. Bone metastases occurred at a mean of 33.3 ± 32.4 months (range 3 - 108) after the diagnosis. After bone metastasis, 6 patients died after an average of 40.3 ± 26.7 months (range 12-84 months). One patient with a pathologic fracture in the proximal humerus underwent resection arthroplasty, 1 patient with metastases in the proximal femur underwent resection arthroplasty, 2 patients with metastases to the femoral shaft underwent curettage-cementation (C&C) and intramedullary nailing, and 1 patient with persistent pelvic pain underwent C&C. No surgery was performed in the other patients. CONCLUSION: In patients diagnosed with uterine leiomyosarcomas, survival did not differ between palliative surgery and conservative treatment after appendicular bone metastases. Patient assessment should be individualized, and overall health should be evaluated before palliative surgery is performed. LEVEL OF EVIDENCE: IV.

An Extra-articular Ganglion Cyst with Multiple Fluid-Fluid Levels.

INTRODUCTION: Ganglion cysts are the knee's most common benign soft tissue tumors. Ganglion cysts are seen as multiloculated fluid collections on magnetic resonance imaging (MRI), and fluid-fluid levels are not an expected finding. CASE PRESENTATION: A 36-year-old female patient presented with swelling in her right knee. Magnetic resonance imaging revealed a multiseptated cyst with multiple fluid-fluid levels within the anterior of the right patellar tendon. Open surgical excision was performed, and the pedicle of the cyst was dissected. The histopathology revealed a ganglion cyst with hemorrhage. CONCLUSION: The ganglion cysts should be considered in the differential diagnosis of lesions with fluid-fluid levels, in addition to hemangioma, synovial sarcoma, and aneurysmal bone cysts of soft tissues.

Isolated Cerebral Cyst Hydatid Removal with Dowling's Technique in a 6-Year-Old Pediatric Patient: Case Report.

Hydatid disease, caused by the Echinococcus parasite, is a worldwide zoonosis produced by the larval stage of the tapeworm. In urban living patients with cerebral abscesses, hydatid cysts should not be excluded from the differential diagnosis. We report an exceptional primary cerebral hydatid cyst in which imaging showed a large, round, contrast-enhancing lesion with a mass effect. The patient presented with a dull headache for over a year and progressively worsened left hemiparesis. The magnetic resonance imaging showed a huge intracranial mass, and the pathology was corrected with cyst hydatid. Surgery was performed via Dowling's technique, and the patient recovered without neurologic deficits. Echinococcosis should be considered a differential diagnosis for single or multiple cerebral abscesses, even in the absence of liver infections. The history of living in rural areas does not exclude cerebral hydatid cysts and Echinococcus .

Evaluation of HSP-27, BAP1, BRAF V600E, CCR7, and PD-L1 expression in uveal melanoma on enucleated eyes and metastatic liver tumors.

BACKGROUND: The presence of metastatic disease is one of the most important factors limiting survival in patients with uveal melanoma. Studies on proteins associated with metastatic mechanisms are sparse in the literature. METHODS: Enucleation samples from 15 patients with metastatic uveal melanoma (Group 1), liver metastasectomy samples from 8 patients with metastatic uveal melanoma (Group 2), and enucleation samples from 20 patients with non-metastatic uveal melanoma as controls (Group 3) were included in the study. Antibodies against heat shock protein 27 (HSP-27), BRCA1-associated protein-1 (BAP1), C-C chemokine receptor 7 (CCR7), B-Raf proto-oncogene serine/threonine-protein kinase V600E (BRAF V600E), and programmed death-ligand 1 (PD-L1) were used to detect immunoreactivity in each sample by immunohistochemical methods. Correlations between these expressed proteins and selected histopathological and clinical features, and metastatic process were investigated. RESULTS: The frequencies of HSP-27 (median score: Group 1: 8, Group 2: 12, Group 3: 4) and BRAF V600E expressions (number of samples: Group 1: 4 (26.7%), Group 2: 1 (12.5%), Group 3: 0 (0%)), and BAP1 expression loss (number of samples : Group 1: 12 (80%), Group 2: 8 (100%), Group 3: 9 (45%)) were higher in samples from patients with metastatic uveal melanoma (Group 1 + 2) than in those from patients with non-metastatic disease (Group 3) (P = 0.001, P = 0.034, and P = 0.007, respectively). CCR7 expression (median score: Group 1: 0, Group 2: 2, Group 3: 3) was similar among these three groups (P = 0.136). No samples exhibited PD-L1 expression (P = 1.000). One-unit increases in the HSP-27 expression level and BAP1 expression loss were significantly related to 1.375- and 7.855-fold increases in the risk of metastasis, respectively (P = 0.007 and P = 0.017). CONCLUSION: HSP-27 and BAP1 are considered to be associated with metastasis, indicating these proteins as potential treatment targets in metastatic uveal melanoma.

Evaluation of the Efficiency of the Graft Material Combined with Ozonized Blood in Maxillary Sinus Lifting Applications in Rabbits.

Objectives: The aim of this study is to investigate the effect of the graft material combined with ozonized blood on bone healing in rabbit in maxillary sinus lifting applications histomorphometrically, immunohistochemically and microtomographically. Materials and Methods: Twenty-eight New Zealand rabbits were randomly divided into 2 groups as experimental (n = 14) and control (n = 14). In experimental group, 5 ml (milliliter) blood obtained from the ear vein of each rabbit was ozonized by 80 µl (µl)/ml concentration ozone-oxygen mixture. Graft material was combined with this ozonized blood. In control group, the graft was combined with saline solution at 0.9% concentration. A 5 mm (millimeter) in diameter window was created on right maxillary sinus window in each rabbit under general anesthesia by local anesthesia support. Sinus membrane was elevated and the space was augmented by 1 cc (cubic centimeter) graft material. One rabbit from the control group which was planned to sacrifice at the end of 8 weeks could not participate in the evaluation because of the extensive inflammation at the operation site. Newly formed bone area and bone density were measured using by image analysis program. Bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF) and collagen-1 (COL-1) analyses were carried out immunohistochemically. The amount of the newly generated bone and the amount of the total augmented space were calculated volumetrically by microtomography. Results: According to histomorphometrical analysis, although newly formed bone area has increased in both experimental and control group with time, statistically significant results were obtained when only O-8 (ozone-treated experimental group planned to be sacrificed after 8 weeks) and O-4 (ozone-treated experimental group planned to be sacrificed after 4 weeks) groups were compared (p = 0,037). The increase in new bone density was seen in both experimental and control groups with time and the results were statistically significant when O-8 group compared to O-4 and C-4 group (ozone-free control group planned to be sacrificed after 4 weeks) (p = 0,07 and p = 0,04, respectively) and C-8 (ozone-free control group planned to be sacrificed after 8 weeks) group compared to C-4 group (p = 0,023). According to immunohistochemical analysis, the intensity and the severity of field staining with anti-BMP-2 have increased in experimental group whereas it has decreased in control group but despite that there was no statistically significance among all groups compared to each other. The number of new vessels stained with anti-VEGF has increased in both experimental and control group with time and multiple comparison results were statistically significant when O-8 group compared with O-4 and C-4 (p = 0,000, p = 0,000, respectively), O-4 group compared with C-8 (p = 0,000) and C-8 group compared with C-4 (p = 0,000). Although the intensity and the severity of field staining with anti-COL-1 have increased in both experimental and control group with time, there was no statistically significance among all groups compared to each other. According to microtomographical analysis, the percentage of the volume of the newly generated bone in the total augmented space volume has decreased with time in both experimental and control groups. Conclusions: Considering the results of this study, the graft material combined with the ozonized blood increased the density of the newly generated bone and the number of new vessels in maxillary sinus lifting applications in rabbits. Clinical Relevance: We suggest further studies should be done combining the graft with ozone by different methods, dosages and exposure times.

Papillary Tumor of the Pineal Region with Parinaud Syndrome: A Case Report.

Backround: Less than 1% of all intracranial tumors are in the pineal region. Papillary tumor of the pineal region is considered one of four pineal parenchymal tumors according to the 2007 World Health Organisation classification of central nervous system tumors. It is mostly seen in the middle age and it is rare under the age of 17 in the literature. In this report, we aim to present a case with papillary tumor of the pineal region with both CT and MRI findings, and discuss the differential diagnosis. Case report: A 17-year-old female patient who underwent a treatment of ventriculoperitoneal shunt due to hydrocephalus 18 months ago applied to the neurosurgery clinic with nausea, vomiting, sensorineural hearing loss and Parinaud syndrome continuing through 1 month. Computed tomography (CT) and magnetic resonance imaging (MRI) have been applied. A 58x31x38 mm mass with cystic and mild hyperdense soft tissue components was observed in the localization of pineal gland and posterior comissure on non-enhanced CT. MRI examination revealed that the mass filled the pineal region, contained solid and large cystic components, and hyperintense on T1-weighted images. After intravenous contrast media injection, the mass enhanced more peripherally. DW-MRI showed that there is a diffusion restriction in some parts of the soft tissue components. The mass was totally resected, and pathology report revealed that it is a papillary tumor of the pineal region. Conclusion: When a T1-weighted hyperintense and CT hyperdense mass with cystic and solid components is seen in the pineal region, even if it is rare, papillary tumor should also be considered in the differential diagnosis after exclusion of other hyperintense lesions in T1-weighted imaging.

Is there any correlation among MKK4 (mitogen-activated protein kinase kinase 4) expression, clinicopathological features, and KRAS/NRAS mutation in colorectal cancer.

BACKGROUND: We aimed to evaluate the correlation between MKK4 expression and clinicopathological features, KRAS/NRAS mutation in colorectal cancer. METHODS: MKK4 expression was assessed by immunoreactivity score (IRS). Staining intensity(SI) and percentage of positively stained cells (PP) were used for IRS (IRS = SI×PP). Cutoffs were explored with ROC analysis. Patients were grouped as WIR ('weak immunoreactive'; IRS:0-2) and SIR ('strong immunoreactive'; IRS: >3). RESULTS: We enrolled 95 patients. 63.2% had metastasis. Median follow-up was 31.4 months. KRAS/NRAS mutation rate was 45.2%. Median values for OS, DFS, and PFS were as 31.6, 17.2, and 10.3 months. WIR group had longer OS (p = 0.03). Recurrence rate was 36.8%. Median DFS was longer for recurrent patients in WIR group (p = 0.055). KRAS or NRAS wild-type patients and those with left-sided tumors in WIR group had longer OS (p = 0.029, p = 0.024, p = 0.03). There was no PFS difference (p: 0.15). In correlation analysis, there was a negative correlation between MKK4 expression and KRAS mutation, NRAS mutation, OS, PFS, DFS (r: -0,06; r: -0,02; r: -0,10; r: -0,06; r: -0,34). Only the correlation for MKK4 expression and DFS was significant (p = 0.04). CONCLUSION: MKK4 expression inversely correlates with survival outcomes. Patients with KRAS/NRAS wild-type, left-sided tumors with WIR had longer OS.

A rare cause of primary hyperparathyroidism: Parathyroid lipoadenoma.

OBJECTIVE: The main cause of primary hyperparathyroidism is a single parathyroid adenoma. Parathyroid lipoadenomas contain abundance of fat cells. Because of these histological features, they can mimic normal parathyroid tissue at the histopathologic examination and radiological imaging could be difficult to localize lipoadenomas. CLINICAL PRESENTATION: In this case report, we present three cases of functional parathyroid lipoadenomas. CONCLUSION: Preoperative imaging modalities often can't localize lipoadenoma. In our cases, SPECT has seen more successful than ultrasonography or CT. There may not be gender predominance at parathyroid lipoadenomas. Intraoperative pathology consultation and rapid biochemical workup can help the surgeon in difficult cases.

Kikuchi-Fujimoto disease coexisted with Sjogren's syndrome.

Here we described a case of primary Sjogren's syndrome that coexisted with Kikuchi-Fujimoto disease.

The correlation between TTF-1 immunoreactivity and the occurrence of lymph node metastases in patients with lung cancer.

AIMS AND BACKGROUND: Thyroid transcription factor (TTF-1) is a tissue-specific transcription factor expressed in the epithelial cells of thyroid and lung. The aim of this study was to evaluate the relationship between the expression of TTF-1 and clinico-pathological parameters in pulmonary adenocarcinoma and adenosquamous carcinoma. METHODS: Resection material of pneumonectomies and lobectomies of 39 patients was retrospectively examined. Twenty-eight patients were diagnosed with adenocarcinoma and 11 with adenosquamous carcinoma. Tumors were classified into 3 groups: a strongly positive group (++) with double dagger 50% tumor cells positive for TTF-1; a weakly positive group (+) with 1-49% positive tumor cells; and a negative group (-) with less than 1% or no positive tumor cells. Analysis was performed with Kaplan-Meier estimates and log-rank tests. RESULTS: Staining for TTF-1 was negative in 10 cases. There was focal staining in 9 cases, while there was diffuse staining in 20 (51%) cases out of 39, and 15 (75%) of these were adenocarcinomas. There was a statistically significant association between TTF-1 and lymph node metastases (P = 0.029). No relationship was found between TTF-1 positivity and disease-free and overall survival. CONCLUSIONS: TTF-1 expression may be a predictor of lymph node metastases. Additional work in a larger group of patients is needed to better assess the utility of this marker.

Correlation of Ki-67 proliferation index and 18-fluorodeoxyglucose uptake in colorectal incidental lesions detected by positron emission tomography-computed tomography.

BACKGROUND/AIM: To investigate whether focal high maximum standardized uptake value (SUVmax) determined by 18-fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) imaging is correlated with proliferation index in the colorectal region. MATERIALS AND METHODS: SUVmax values of 31 colorectal neoplasms that were incidentally detected during PET-CT examination were compared to dysplasia degree, histopathologic diagnosis, and immunohistochemical expression of the Ki-67 proliferation marker. RESULTS: Statistically significant correlations were found between SUVmax and Ki-67 proliferation index, dysplasia degree, and histopathologic diagnosis. Median SUVmax value was found to be significantly higher in high-risk lesions than low-risk lesions. CONCLUSION: The Ki-67 proliferation index is an indicator of SUVmax in colorectal tract. SUVmax values can predict malignancy and prognosis in this region. Colonoscopy and biopsy should always be performed whenever a focal high FDG uptake is determined incidentally in a patient.