Orbital fat is an adipose tissue located behind orbital septum and originates from mesoderm and neural crest in ectoderm. It has been found that the histologic structure of orbital fat is different from subcutaneous and visceral fat. In addition, the regeneration and anti-inflammatory ability of stem cells derived from orbital fat have attracted much attention in recent years. This paper reviews the recent research progress on orbital fat, including its structure, origin, histological characteristics, and related stem cells.

BACKGROUND: An important reason for the high health care costs associated with bladder cancer is the need for frequent cystoscopy for detection and surveillance of this disease. Cytologic analysis of voided urine specimens can assist, but is too inaccurate to replace cystoscopy. In an effort to create reliable, objective, noninvasive mechanisms for detecting bladder cancer, a number of urine-based molecular tests have been developed with the ultimate goal of reducing the frequency of cystoscopy.
OBJECTIVE: To summarize the performance of urine-based biomarker tests, currently commercially available in the US, as part of the initial workup for hematuria and for bladder cancer surveillance.
METHODS: In accordance with PRISMA guidelines we performed a systematic review of the literature on the performance of NMP22, BTA, UroVysion, ImmunoCyt/uCyt, CxBladder, and Bladder EpiCheck. Median sensitivity, specificity, negative (NPV) and positive predictive values (PPV) were calculated for each test based on the included studies.
RESULTS: Twenty-eight studies met inclusion criteria for the performance of five urine-based biomarker tests in the setting hematuria workup. Median sensitivity ranged from 65.7% -100% and specificity ranged from 62.5% -93.8%. Median NPV ranged from 94.2% -98.3% and PPV ranged from 29% -58.7%. Fourteen studies met inclusion criteria for the performance of six tests in the setting of bladder cancer surveillance. Median sensitivity ranged from 22.6% -92.0% and specificity from 20.5% -97.9%. Median NPV ranged from 52.9% -96.5% and PPV ranged from 48.1% -75.7%.
CONCLUSIONS: Our analysis finds that while these tests may provide some clinical utility, none of the assays have thus far demonstrated objective evidence to supplant the gold diagnostic standard.

Primary mucinous cystadenocarcinoma (MCA) of the breast is a rare variant of breast carcinoma. A 68-year-old female patient presented to the general surgery clinic with pain and swelling in the right breast. A mass was detected in the upper outer quadrant, and a fine-needle aspiration biopsy was performed. The May-Grünwald Giemsa stained slides showed aggregates of mucin-rich pleomorphic cells with large nuclei in a mucinous background containing discohesive single cells. The Papanicolaou stain revealed a papillary structure composed of malignant epithelial cells in a necrotic background. A modified radical mastectomy was performed, and upon gross examination, two tumors were discovered in the central and upper outer quadrants. The first tumor, located centrally, was identified as invasive lobular breast carcinoma. The second tumor was an MCA with cytokeratin 7(+) and cytokeratin 20(-), and was determined to be the primary MCA of the breast based on clinical and radiological information. Immunohistochemistry revealed that the tumor cells were negative for estrogen receptor and progesterone receptor, and HER2 was 2+. Fluorescence in situ hybridization analysis detected HER2 gene amplification. During the 72-month follow-up, there were no findings compatible with recurrence or new metastasis. Although primary MCA is rare, it causes differential diagnosis problems and has different biological behaviors.

Following the introduction of RNA-based vaccines, COVID-19 vaccine-associated clinical lymphadenopathy (C19-LAP) has been reported as a side effect. Moreover, subclinical lymphadenopathy detected on imaging (SLDI) has also been observed, mainly as incidental findings while performing screening tests on oncological patients. In these cases, surgical lymphadenectomy, fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB) have been used as a valuable diagnostic tool for SLDI and C19-LAP. In this review the clinical, histologic and cytologic features of SLDI and C19-LAP have been investigated. A search for studies that reported on C19-LAP and SLDI histopathology and cytopathology was performed on PubMed and Google Scholar, on 11 January 2023. Thirty-one reports on SLDI and C19-LAP were retrieved and included in a pooled analysis. In total, we included 54 patients with a median age of 47 years. In our research, surgical excision, CNB and/or FNAC of C19-LAP or SLDI enlarged lymph nodes have been performed in 54 cases. Of all cases, only two metastases were diagnosed and one case was diagnosed as reactive hyperplasia with atypical follicles. The remaining cases were reactive lymphadenopathy (28 cases), follicular hyperplasia (13 cases), Kikuchi-Fujimoto disease (6 cases), granulomatous lymphadenitis (2 cases), eosinophilic lymph node abscesses (1 case), Langherans cell histiocytosis (1 case), Rosai-Dorfman disease (1 case). SLDI and C19-LAP have represented a diagnostic dilemma, especially in oncologic patients. The role of different diagnostic tools for SLDI and C19-LAP has been discussed.

BACKGROUND: Ocular cytology is an effective method of diagnosing infective, benign, and malignant ocular disease processes due to easy accessibility and rapid turnaround time. However, these specimens pose significant diagnostic challenges due to rarity of the specimen type, sparse diagnostic material available for ancillary workup, and unfamiliarity of the diagnostic entities by the cytopathologist.
METHODS: This study conducted a 6-year comprehensive review of 65 eye cytology cases received at a tertiary level hospital. Cytopathologic diagnoses of \"negative for malignancy\" and \"atypical\" were categorized as negative findings (70.8%, n = 46) and diagnoses of \"suspicious for malignancy\" and \"positive for malignancy\" were categorized as positive findings (23.1%, n = 15). A 44.6% (n = 29) of cases had subsequent histopathology and/or flow cytometry diagnoses. Premalignant and malignant lesions detected on histopathology were considered as significant findings. Statistical analysis was performed to evaluate the concordance of ocular cytology with associated histopathology and/or flow cytometry diagnoses.
RESULTS: The accuracy of final cytology-histopathology and/or cytology-flow cytometry diagnoses in this cohort of cases is 86.2%. The sensitivity and specificity of ocular diagnosis by cytology are 66.6% and 100%, respectively. The positive and negative predictive values of ocular diagnosis by cytology are 100% and 80.9%, respectively.
CONCLUSIONS: Ocular cytology is a fast, effective, and sensitive method for diagnosing ocular pathology specimens. Familiarity with these specimen types by cytopathologists can help in diagnosing ocular diseases effectively on small, challenging cytologic preparations.

UNASSIGNED: The overall diagnostic value of fine-needle aspiration (FNA) is not as excellent as that of core needle biopsy (CNB). Limited research has investigated small cervical lymph nodes inaccessible to ultrasound-guided CNB due to technical challenges associated with their small size. Therefore, this study aimed to evaluate the accuracy of ultrasound-guided FNA in determining the etiology of small cervical lymph nodes.
UNASSIGNED: A retrospective analysis was conducted on patients who underwent FNA between May 2018 and May 2021 at our hospital. Cytological, histopathological, and clinical follow-up data were analyzed. The diagnostic yield of FNA was assessed based on sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy calculations.
UNASSIGNED: This study included 505 patients, each with a small cervical lymph node under evaluation (total number of lymph nodes: 505). The average maximal diameter of the lymph nodes was 14.6 ± 6.2 mm. According to the Sydney system, the cytology results were as follows: Category I in 26 lymph nodes (5.1 %); Category II in 269 (53.3 %); Category III in 35 (6.9 %); Category IV in 17 (3.4 %); and Category V in 158 (31.3 %). We identified 212 malignant cases (203 metastases and 9 lymphomas) and 293 benign lymph nodes. FNA achieved high sensitivity (88.8 %), specificity (99.6 %), PPV (99.4 %), NPV (91.8 %), and overall accuracy (94.8 %) in determining the etiology of small cervical lymph nodes.
UNASSIGNED: FNA cytology is suitable for small lesions inaccessible by CNB and provides a diagnostic basis for implementing clinically appropriate treatment measures.

Background and Objectives: The impact of positive peritoneal cytology has been a matter of controversy in early-stage endometrial cancer for several years. The latest staging systems do not take into consideration its presence; however, emerging evidence about its potential harmful effect on patient survival outcomes suggests otherwise. In the present systematic review and meta-analysis, we sought to accumulate current evidence. Materials and Methods: Medline, Scopus, the Cochrane Central Register of Controlled Trials CENTRAL, Google Scholar and Clinicaltrials.gov databases were searched for relevant articles. Effect sizes were calculated in Rstudio using the meta function. A sensitivity analysis was carried out to evaluate the possibility of small-study effects and p-hacking. Trial sequential analysis was used to evaluate the adequacy of the sample size. The methodological quality of the included studies was assessed using the Newcastle-Ottawa scale. Results: Fifteen articles were finally included in the present systematic review that involved 19,255 women with early-stage endometrial cancer. The Newcastle-Ottawa scale indicated that the majority of included studies had a moderate risk of bias in their selection of participants, a moderate risk of bias in terms of the comparability of groups (positive peritoneal cytology vs. negative peritoneal cytology) and a low risk of bias concerning the assessment of the outcome. The results of the meta-analysis indicated that women with early-stage endometrial cancer and positive peritoneal cytology had significantly lower 5-year recurrence-free survival (RFS) (hazards ratio (HR) 0.26, 95% CI 0.09, 0.71). As a result of the decreased recurrence-free survival, patients with positive peritoneal cytology also exhibited reduced 5-year overall survival outcomes (HR 0.50, 95% CI 0.27, 0.92). The overall survival of the included patients was considerably higher among those that did not have positive peritoneal cytology (HR 12.76, 95% CI 2.78, 58.51). Conclusions: Positive peritoneal cytology seems to be a negative prognostic indicator of survival outcomes of patients with endometrial cancer. Considering the absence of data related to the molecular profile of patients, further research is needed to evaluate if this factor should be reinstituted in future staging systems.

This is the first systematic review and meta-analysis of The International System (TIS) for reporting serous fluid cytopathology. Our aims were to present the pooled malignancy rate of each TIS reporting category and the diagnostic accuracy of cytology using this system. Database search using a predefined strategy was followed by study selection, data extraction, study quality assessment, and statistical analysis. Data derived from 16 eligible studies were pooled. The pooled rates of malignancy were as follows: 27% (95% CI; 16%-41%) for \"nondiagnostic\" (ND), 11% (95% CI; 7%-18%) for negative for malignancy\" (NFM), 49% (95% CI; 37%-61%) for \"atypia of undetermined significance\" (AUS), 90% (95% CI; 81%-95%) for \"suspicious for malignancy\" (SFM), and 100% (95% CI; 98%-100%) for \"positive for malignancy\" (MAL). Studies performed exclusively in cancer hospitals showed higher pooled malignancy rates, compared with academic and community hospitals serving the general population, in the ND [40% (95% CI; 21%-62%) vs. 22% (95% CI; 11%-39%)], NFM [20% (95% CI; 13%-30%) vs. 9% (95% CI; 5%-17%)], and AUS categories [55% (95% CI; 47%-63%) vs. 46% (95% CI; 31%-62%)]. Notably, the difference was significant in the NFM category ( P =0.04). When both SFM and MAL cytology interpretations were considered as malignant outcomes, the pooled sensitivity and specificity were 68.74% (95% CI; 59.90%-76.39%) and 98.81% (95% CI; 98.18%-99.22%), respectively. In addition, the diagnostic odds ratio (DOR) was found to be 170.7 (95% CI; 96.2-303.3). Despite its strengths, our study also had some limitations. Therefore, future large-scale longitudinal studies could strengthen the findings of this review.

Cytological examination of urine sediment is a helpful diagnostic tool for identifying renal involvement by hematological malignancies. We present the case of a 47-year-old man who was diagnosed with extranodal B-lymphoblastic lymphomas after presenting with gross hematuria as his first symptom. The presence of lymphoma cells in the urine led to a diagnosis confirmed through an immunophenotypic study using cell block sections of urine centrifuge sediment and core needle biopsy histology of the right renal pelvis mass. This case highlights the usefulness of a urine cytological study in diagnosing lymphoma involvement in the genitourinary tract. Furthermore, this paper reviews relevant literature on diagnosing lymphoma involvement from urine sediment.

The cytomorphology of MPNST in effusion specimens is rarely described. In this paper, the detailed cytopathological and immunohistochemical characteristics of metastatic MPNST has been described in pleural effusion. Patients\' medical history and the judicious utilization of ancillary studies contribute to ensure precise cytological diagnoses. The cytomorphology of malignant peripheral nerve sheath tumour (MPNST) in effusion specimens can be diagnostically challenging. The author presents detailed cytopathological and immunohistochemical characteristics of a case of metastatic MPNST in pleural effusion.