Massive Thymic Hyperplasia Masquerading as Cancer: A Case Report and Review of the Literature.

A 34-year-old woman presenting with abdominal pain, chest pressure, weight loss, and tachycardia was found to have an 11.4-cm anterior mediastinal mass associated with intrathoracic lymphadenopathy on chest computed tomography (Fig. 1A). Core needle biopsy was concerning for a type B1 thymoma. During this patient's initial workup, she was found to have both clinical and laboratory evidence of Graves' thyroiditis, raising diagnostic suspicion for thymic hyperplasia rather than thymoma. The case discussed here highlights the unique challenges that arise in the evaluation and management of thymic masses and serves as a prudent reminder that both benign and malignant disorders may present with mass-like changes.

JAK2 Mutations Are Rare and Diverse in Myelodysplastic Syndromes: Case Series and Review of the Literature.

OBJECTIVES: To investigate and characterize JAK2 mutations in myelodysplastic syndrome (MDS), we present three cases with diverse JAK2 mutations and review the literature. METHODS: The institutional SoftPath software was used to find MDS cases between January 2020 and April 2022. The cases with a diagnosis of a myelodysplastic/myeloproliferative overlap syndrome including MDS/MPN with ring sideroblasts and thrombocytosis were excluded. The cases with molecular data by next generation sequencing looking for gene aberrations commonly seen in myeloid neoplasms were reviewed for the detection of JAK2 mutations including variants. A literature review on the identification, characterization, and significance of JAK2 mutations in MDS was performed. RESULTS: Among 107 cases of the MDS reviewed, a JAK2 mutation was present in three cases, representing 2.8% of the overall cases. A JAK2 V617F mutation was found in one case representing slightly less than 1% of all the MDS cases. In addition, we found JAK2 R564L and JAK2 I670V point mutation variants to be associated with a myelodysplastic phenotype. CONCLUSIONS: JAK2 mutations in MDS are rare and represent less than 3% of cases. It appears that JAK2 variant mutations in MDS are diverse and further studies are needed to understand their role in the phenotype and prognosis of the disease.

Extended B-cell depletion beyond 6-months in patients receiving ocrelizumab or rituximab for CNS demyelinating disease.

OBJECTIVES: To investigate the duration of B-cell depletion in a cohort of patients receiving ocrelizumab or rituximab for multiple sclerosis (MS) or neuromyelitis optica spectrum disorders (NMOSD). METHODS: We retrospectively searched our database for patients diagnosed with MS or NMOSD, who were receiving ocrelizumab or rituximab and had available CD19 measurements. We collected demographic data, infusion doses, infusion dates, CD19 absolute counts and percentages, and their collection dates. We paired each infusion with the subsequent CD19 measurements recorded before the next infusion, discarding measurements done during a washout period of 30 days after each infusion. We applied three definitions for B-cell depletion, the most stringent of which was an absolute B-cell count ≤20 cells/uL. RESULTS: From 695 patients with demyelinating diseases in our database, over the period of January 1st 2010 to March 1st 2020, we identified 188 patients (178 with MS and 10 with NMOSD), who had received ocrelizumab or rituximab and had available CD19 measurements. 1054 CD19 measurements were captured. B-cell depletion, as defined above, was recorded as far out as 22.8 months after an ocrelizumab infusion, and 22.3 months after a rituximab infusion. Out of 90 B-cell measurements done ≥8 months (>210 days) after ocrelizumab infusion, 45(50%) measurements showed B-cell depletion. Similarly for rituximab, out of 113 measurements, 49(43%) showed B-cell depletion. CONCLUSIONS: This study demonstrates that B-cell depletion after ocrelizumab and rituximab continues beyond the traditional 6-month re-infusion interval in many patients. Our report provides data that can support clinical trials testing increasing the interval of re-infusion with ocrelizumab and rituximab beyond 6-months guided by B-cell measurements.

Role of CD68 immunohistochemistry in categorizing benign nonmesothelial cell population and refining "atypical" category in serous fluid cytology.

BACKGROUND: Body fluids are rich in histiocytes and may mimic atypical epithelial cells morphologically. Histiocytes can pose a significant challenge in serous fluid cytology as they tend to appear atypical due to prolonged accumulation in serous fluids in vivo and processing by liquid-based cytology in vitro. Not many studies have documented the utilization of histiocytic marker such as CD68 in serous fluid cytology, which can subsequently reduce the "atypical" diagnostic category. METHODS: One thousand one hundred and twenty-nine cases of serous fluid cytology from 2016 to 2019 were reviewed and reclassified based on proposed classification of the international system for reporting serous fluid cytology. There were 133 cases with atypical diagnoses, out of which 51 cases had cellblocks. An immunohistochemistry (IHC) panel, including two mesothelial markers, two epithelial markers, and one histiocytic marker was applied to the atypical samples. Same IHC panel was utilized to evaluate 15 cases each from negative for malignancy (NFM), suspicious for malignancy (SFM), and malignant (MAL) categories for further comparison. RESULTS: After reevaluation of the cytology material with IHC stains, 924 (82%), 133 (12%), 23 (2%), and 49 (4%) of the cases were reclassified as NFM, atypia of uncertain significance, SFM, and MAL, respectively. Twenty-five out of 51 atypical cases (49%) were downgraded to "benign" after reevaluation with CD68 IHC. CONCLUSION: Histiocytes can mimic atypical epithelial cells in body fluids. Effective utilization of CD68 IHC will be beneficial in further refining the "atypical" diagnostic category in serous fluid cytology.

New/Revised Entities in Gastrointestinal Lymphoproliferative Disorders.

The gastrointestinal tract is a common extranodal site of involvement by lymphomas. These may be diagnostically challenging because they can mimic a variety of benign conditions and may be difficult to subclassify when malignant. The classification of gastrointestinal lymphomas is an evolving area with some recent changes. Although some of these entities are rare, they are important to recognize because of the variable clinical presentations, comorbidities, and treatment implications. This article explores new and revised entities in gastrointestinal lymphoproliferative disorders.

Biofilm Formation on Bandage Contact Lenses Worn by Patients with the Boston Type 1 Keratoprosthesis: A Pilot Comparison Study of Prophylactic Topical Vancomycin 15 mg/mL and Linezolid 0.2.

OBJECTIVES: To determine the rate of biofilm formation on bandage contact lenses worn by patients with the Boston type 1 keratoprosthesis (K-Pro) while on prophylactic topical vancomycin versus linezolid. METHODS: Patients wearing a bandage contact lens (BCL) with a K-Pro were eligible for enrollment. After irrigation of the ocular surface with 5% povidone-iodine solution, each patient was placed on either topical vancomycin 15 mg/mL or linezolid 0.2% BID for one month. At the one-month visit, the BCL was collected and stored in fixative solution. Standard photographs were taken of each lens at high magnification using scanning electron microscopy (SEM), which were subsequently analyzed for evidence of biofilm. RESULTS: Nineteen contact lenses were obtained from 12 K-Pro patients at the Illinois Eye and Ear Infirmary. Zero of eight (0%; 95% CI=0 to 37%) contact lenses from patients treated with topical vancomycin, and 1 of 11 (9%; 95% CI=0 to 41%; P-value=1.00) contact lenses from patients treated with topical linezolid were found to have biofilm formation at one month as detected by SEM. None of the patients developed a clinically significant infection while on either prophylactic vancomycin or linezolid during the study period. CONCLUSIONS: Overall, the rate of biofilm formation as detected by SEM on the surface of bandage contact lenses was low. These results suggest that vancomycin and linezolid are both relatively effective in reducing biofilm-forming bacterial growth at one month. Accordingly, linezolid may be an effective alternative to vancomycin in patients with allergy or intolerance. However, further investigation is required to develop evidence-based antibiotic prophylaxis regimens.

Concordant clear cell "mesonephric" carcinoma of the bladder and lung adenocarcinoma with clear cell features - multiple primaries versus metastatic neoplasms: a case report.

BACKGROUND: Clear cell carcinoma of the bladder is a rare variant of urinary bladder adenocarcinoma. We report a case of a patient with clear cell carcinoma of the bladder and a concordant right upper lobe pulmonary adenocarcinoma with clear cell features, and we address the role of immunohistochemistry and cytogenetic analysis in distinguishing the two primary malignancies. CASE PRESENTATION: Our patient was a 59-year-old African American woman who presented with hematuria. Her past medical history included invasive mammary carcinoma and end-stage renal disease treated with hemodialysis. A computed tomographic urogram revealed a 3-cm polypoid bladder mass. A follow-up chest computed tomographic scan revealed a 1-cm right upper lobe nodule. The patient underwent transurethral biopsy and subsequent radical cystectomy, as well as a transthoracic core needle biopsy of the lung nodule. Histologically, the bladder tumor consisted of flat, cuboidal to columnar cells with clear or eosinophilic cytoplasm and a hobnail appearance, organized in tubulocystic and papillary patterns. The neoplastic cells were diffusely positive for α-methylacyl-coenzyme A racemase, cancer antigen 125, and cytokeratin 7; focally positive for cytokeratin 20, P53, and carcinoembryonic antigen; and negative for thyroid transcription factor 1. The lung tumor demonstrated a glandular architecture with mucin production (positive for mucin with mucicarmine and periodic acid-Schiff with diastase stain). The neoplastic cells were diffusely positive for cytokeratin 7, napsin A, and thyroid transcription factor 1, and they were negative for cytokeratin 20 and cancer antigen 125. Genetic testing of the pulmonary neoplasm demonstrated ARID2 genomic alterations. CONCLUSIONS: The presence of clear cell features in both neoplasms raised the possibility of lung metastasis from the primary bladder tumor. However, the glandular architecture of the lung neoplasm along with its distinctive immunohistochemical and genetic profiles confirmed the presence of two separate primaries.

Evaluation of Accessory Lacrimal Gland in Muller's Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease.

PURPOSE: The accessory lacrimal glands (ALGs) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential, and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. MATERIALS AND METHODS: ALG tissues obtained from Muller's muscle conjunctival resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. RESULTS: Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2, and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. CONCLUSIONS: Thus, we report for the first time that human ALG tissues contain precursor marker-positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES, and isolate candidate precursor cells from ALG tissue.

Histatin-1 Expression in Human Lacrimal Epithelium.

BACKGROUND: Study of human lacrimal cell biology is limited by poor access to tissue samples, heterogeneous cell composition of tissue and a lack of established lacrimal epithelial markers. In order to further our understanding of lacrimal cell biology, we sought to find a better marker for human lacrimal epithelial cells, compared to what has been reported in the literature. METHODS: We utilized human Muller's muscle conjunctival resection (MMCR) specimens containing accessory lacrimal gland (ALG) and cadaveric main lacrimal gland (MLG) as sources of lacrimal tissue. Candidate markers were sought using human ALG tissue from MMCR specimens, isolated by laser capture microdissection (LCM). Affymetrix® analysis was performed on total RNA isolated from FFPE samples to profile transcription in ALG. MMCR tissue sections were assessed by immunofluorescence using antibodies for histatin-1, lactoferrin, E-cadherin (E-cad) and alpha-smooth muscle actin (ASMA). Reverse transcriptase polymerase chain reaction (RT-PCR) analysis was performed to analyze the expression of histatin-1, E-cad and lactoferrin from cadaveric MLG. RESULTS: Histatin-1 is expressed in ALG and MLG, localizes to lacrimal epithelium, and to a greater degree than do other putative lacrimal epithelial markers. CONCLUSIONS: Histatin-1 is a good marker for human lacrimal epithelium in ALG and MLG and can be used to identify lacrimal cells in future studies.

Bacteria Colonizing the Ocular Surface in Eyes With Boston Type 1 Keratoprosthesis: Analysis of Biofilm-Forming Capability and Vancomycin Tolerance.

PURPOSE: To analyze the bacterial microbiota colonizing the ocular surface of patients with Boston type 1 keratoprostheses (K-Pros) for antibacterial resistance patterns and capacity to form biofilms. METHODS: Twenty-seven eyes with a Boston type 1 K-Pro and 16 fellow control eyes from 26 patients were enrolled. The surface of the K-Pro optic and/or the inferior conjunctival fornix was swabbed and plated separately on culture media. Positive cultures were processed to assess for biofilm-forming capability. Microtiter plate adherence assay and polymerase chain reaction for ica and atlE genes were used. An in vitro assay of vancomycin tolerance was performed on isolated strains and compared to standard controls with and without biofilm-forming capability. RESULTS: Eighty-five percent of K-Pro eyes and 69% of control eyes had positive cultures (P = 0.20). All Gram-positive strains exhibited susceptibility to vancomycin by standard testing. Biofilm-forming bacterial isolates were detected in 57.7% of K-Pro eyes and 53.3% of control eyes. A vancomycin tolerance assay showed that the antibiotic susceptibility of coagulase-negative staphylococcus (CNS) within biofilms was significant in only three of five biofilm-forming strains (P < 0.05). In all strains, bacterial cells in planktonic form were more susceptible to vancomycin than in biofilm form (P < 0.001). CONCLUSIONS: Coagulase-negative staphylococcus can be isolated from K-Pro surfaces despite the use of vancomycin prophylaxis. In this study, the majority of isolated strains had biofilm-forming capability. In vitro vancomycin tolerance assays suggest that biofilm formation decreases susceptibility to vancomycin. This may contribute to higher rates of infectious complications observed in these patients.

Symptom burden of patients with dry eye disease: a four domain analysis.

PURPOSE: To determine which sensory (symptom persistence and intensity) and reactive (activity and affective interference) domains of symptom analysis are essential for assessing symptom burden in dry eye disease (DED) patients. METHODS: A symptom domain tool was developed to investigate all four symptom domains in DED. In a cross-sectional pilot study, we administered the symptom burden tool and the Ocular Surface Disease Index (OSDI) questionnaire to 48 DED patients. Total and domain scores from the symptom burden tool and the OSDI were normalized to achieve comparability. Spearman correlation coefficients were calculated to measure the relationship between domains and subscales. Agreement between the symptom burden tool and OSDI was assessed by Bland-Altman plot. Assigned treatments were compared by symptom burden to determine whether treatment aggressiveness is linked to symptom intensity. RESULTS: There was high agreement between the symptom burden tool and the OSDI. Symptom persistence had a stronger correlation with affective interference (r  =  0.62 for the symptom burden tool and r = 0.73 for the OSDI) than activity interference (r = 0.58 for the symptom burden tool and r = 0.60 for the OSDI). Symptom intensity correlated weakly with affective interference (r = 0.38) and activity interference (r = 0.37) in the symptom burden tool (OSDI does not have a subscale for intensity). In patients with equal persistence of symptoms, those having high symptom intensity were receiving more aggressive treatment (66.7%) than those with lower symptom intensity (33.3%). CONCLUSIONS: Persistence of symptoms correlates better with affective interference than activity interference. Intensity of symptoms may be important for treatment decisions.

Tear fluid extracellular DNA: diagnostic and therapeutic implications in dry eye disease.

PURPOSE: To determine the abundance of extracellular DNA (eDNA) in tear fluid of patients with dry eye disease (DED) and to report clinical outcomes after DNase I eyedrops use to reduce excessive tear fluid eDNA. METHODS: Tear fluid was collected from healthy control subjects and patients with DED. The eDNA abundance was determined with the PicoGreen dye assay. The DED symptoms and clinical signs were recorded and correlated with eDNA abundance. Two patients with DED having excessive eDNA in tear fluid were treated with DNase I eyedrops. RESULTS: The PicoGreen dye assay measures tear fluid eDNA abundance after a 2-minute incubation time. With longer incubations, admixed cells also contribute to eDNA measurements. The mean (SE) eDNA abundance in healthy control subjects' tear fluid was 1.4 (0.2) µg/mL. The mean (SE) eDNA abundance in tear fluid of patients with nonautoimmune DED, autoimmune DED, and graft versus host disease was significantly higher: the values were 2.9 (0.6), 5.2 (1.2), and 9.1 (2.3) µg/mL, respectively (P < 0.05). In most of these patients, the PicoGreen dye kinetic assay of tear fluid showed an increase in fluorescence signal due to the presence of viable cells in tear fluid. Tear fluid eDNA had the best correlation with corneal Rose Bengal staining (r = 0.55). Treatment of patients having DED with DNase I eyedrops reduced eDNA abundance, abrogated signal increase, and improved comfort. CONCLUSIONS: Excessive eDNA is present in tear fluid of patients with dry eyes. A novel therapeutic approach for managing DED may be to measure eDNA abundance in tear fluid with the PicoGreen dye assay and reduce excessive amounts with DNase I eyedrops.

CD11b+GR1+ myeloid cells secrete NGF and promote trigeminal ganglion neurite growth: implications for corneal nerve regeneration.

PURPOSE: We characterized fluorescent bone marrow cells (YFP(+) BMCs) in the thy1-YFP mouse and determine if they promote trigeminal ganglion (TG) cell neurite growth. METHODS: Excimer laser annular keratectomy was performed in thy1-YFP mice, and corneas were imaged. BMCs were harvested from femur and tibia, and the expression of surface markers on YFP(+) BMCs was analyzed by flow cytometry. The immunosuppressive action of BMCs (YFP(+) and YFP(-)) was evaluated in an allogenic mixed lymphocyte reaction (MLR). Neurotrophic action of BMCs (YFP(+) and YFP(-)) was determined in compartmental and transwell cultures of dissociated TG cells. RESULTS: Following annular keratectomy, YFP(+) BMCs infiltrated the cornea. YFP(+) BMCs shared surface markers (CD11b+Gr1+Ly6C+Ly6G-F4/80(low)) with monocytic myeloid-derived suppressor cells (MDSCs), had similar morphology, and suppressed T-cell proliferation in allogenic MLR in a dose-dependent manner. YFP(+) BMCs, but not YFP(-) BMCs, significantly increased growth of TG neurites in vitro. When cultured in a transwell with TG neurites, YFP(+) BMCs expressed neurotrophins and secreted nerve growth factor (NGF) in conditioned medium. YFP(+) BMCs that infiltrated the cornea maintained their phenotype and actions (neuronal and immune). CONCLUSIONS: YFP(+) BMCs in thy1-YFP mice have immunophenotypic features of MDSCs. They secrete NGF and promote neuroregeneration. Their immunosuppressive and neurotrophic actions are preserved after corneal infiltration. These findings increase our understanding of the beneficial roles played by leukocyte trafficking in the cornea and may lead to therapeutic strategies that use NGF-secreting myeloid cells to repair diseased or injured neurons.

Ocular surface extracellular DNA and nuclease activity imbalance: a new paradigm for inflammation in dry eye disease.

PURPOSE: We determined whether nucleases are deficient in the tear fluid of dry eye disease (DED) patients, and whether this causes extracellular DNA (eDNA) and neutrophil extracellular trap (NET) accumulation in the precorneal tear film, thus causing ocular surface inflammation. METHODS: Exfoliated cells adhered to Schirmer test strips were collected on glass slides, and immunofluorescence confocal microscopy was used to evaluate neutrophils, eDNA, NETs, and their molecular components. Similar experiments were performed with mucoid films collected from the inferior conjunctival fornix or bulbar conjunctiva. We used quantitative PCR to evaluate eDNA signaling pathways and inflammatory cytokine expression. We also determined the amount of ocular surface eDNA and evaluated tear fluid nuclease activity. RESULTS: eDNA, NETs, and neutrophils were present on the ocular surface in DED patients and abundant in mucoid films. NETs consisted of eDNA, histones, cathelicidin, and neutrophil elastase. Tear fluid nuclease activity was decreased significantly in DED patients, whereas the amount of eDNA on the ocular surface was increased significantly. Expression of genes downstream of eDNA signaling, such as TLR9, MyD88, and type I interferon, as well as the inflammatory cytokines interleukin-6 and tumor necrosis factor-α, was significantly increased in DED patients. CONCLUSIONS: Extracellular DNA production and clearance mechanisms are dysregulated in DED. Nuclease deficiency in tear fluid allows eDNA and NETs to accumulate in precorneal tear film, and results in ocular surface inflammation. These findings point to novel therapeutic interventions in severe DED based on clearance of eDNA, NETs, and other molecular components from the ocular surface.