Non-neoplastic Disorders Research Articles

A Mimicker of Differentiated Vulvar Intraepithelial Neoplasia: Reactive Atypia From Noncompliance With Lichen Sclerosus Therapy.

Differentiated vulvar intraepithelial neoplasia (d-VIN) is an HPV-independent precursor to vulvar squamous cell carcinoma. The histology of d-VIN lesions is difficult to differentiate from that of non-neoplastic epithelial disorders, especially lichen sclerosus (LS). The authors present a case of LS, where relying on histopathology alone could have led to misdiagnosis. The patient was a 17-year-old female patient with clinical features of vulvar dermatitis and LS for 2 years. She was counseled to apply clobetasol 0.05% to the affected area daily but reported no improvement after 6 months. A biopsy of the right labia majora revealed histologic findings typical of d-VIN and near-contiguous p53 expression. These features are characteristic of d-VIN. However, d-VIN is exceedingly rare in young patients. The case was reviewed by 6 dermatopathologists and gynecologic pathologists, who observed that the degree of inflammation would be unusual postclobetasol therapy and could be due to noncompliance. A review of the patient's chart revealed that she "does not always remember to apply" clobetasol. The patient's clinician confirmed that there were compliance issues, and the follow-up biopsy was negative for d-VIN. The case was signed out as LS, with a note describing the above, and to rebiopsy if concern persisted. The authors conjecture that inflammatory infiltrates in the biopsied area caused reactive atypia due to lack of adherence to treatment. Although the patient's age helped rule out d-VIN, similar cases in elderly patients may be occurring. Pathologists must be aware that reactive forms of untreated LS can mimic d-VIN, to avoid misdiagnosis.

Exploring the potential prompting role of cervical human papilloma virus detection in vulvar lesions: a cross-sectional study in China.

The etiology and clinical presentation of vulvar carcinomas, especially vulvar lesions, are not fully understood. Because the vulva and cervix are anatomically connected, human papillomavirus (HPV) is the main cause of cervical lesions. Thus, this study explored the potential characteristics and effects of specific HPV infection types across vulvar lesions and concurrent cervical lesions. This retrospective, cross-sectional study analyzed patients with cervical HPV or cytological results and concurrent vulvar biopsy who were seen in our hospital colposcopy clinic in Shanxi Province, China, between 2013 and 2023. Data on age, menopause status, vulvar manifestations, and cytology and HPV infection testing results were collected. Attributable fractions and multinominal logistic models were used to evaluate HPV genotyping and clinical characteristics across vulvar lesions. Among the 1,027 participants, 83 (8.1%) had vulvar intraepithelial neoplasia (VIN) of high grade or worse (VIN2+), and 127 (12.4%) had non-neoplastic epithelial disorders of the vulva (NNEDV). A total of 175 patients had either VIN2+ or cervical intraepithelial neoplasia (CIN) lesions of grade 2 or worse (CIN2+). The most common HPV genotypes for VIN2+ or concurrent VIN2+/CIN2+ were HPV16, HPV52, and HPV58, although attributable fractions differed among lesions. Patients with normal cytological or histopathological result were more likely to have NNEDV detected, while abnormal cervical diagnosis was associated with higher detection of VIN2+. Multinominal logistic modeling showed that age and HPV16 infection were risk factors for VIN2+ or concurrent VIN2+/CIN2+; however, only vulvar presentation with depigmentation was a risk factor for NNEDV. Among patients with low-grade CIN1/VIN1, compared with those who were HPV16 negative, those who were HPV16 positive were at 6.63-fold higher risk of VIN2+/CIN2+ [95% confidence interval (CI): 3.32, 13.21]. Vulvar depigmentation was also associated with increased risk of NNEDV (odds ratio: 9.98; 95% CI: 3.02, 33.04). Chinese women may be at specific, high risk for HPV infection types associated with VIN or CIN. The use of cervical cell HPV detection along with vulvar presentation during cervical cancer screening may also contribute to vulvar lesion detection.

Transcriptomic analysis of bone marrow specimens collected from Miniature Dachshunds diagnosed with non-neoplastic bone marrow disorders.

Non-neoplastic bone marrow disorders are main causes of non-regenerative anemia in dogs. Despite the high incidence of the diseases, their molecular pathophysiology has not been elucidated. We previously reported that Miniature Dachshund (MD) was a predisposed breed to be diagnosed with non-neoplastic bone marrow disorders in Japan, and immunosuppressive treatment-resistant MDs showed higher number of platelets and morphological abnormalities in peripheral blood cells. These data implied that treatment-resistant MDs might possess distinct pathophysiological features from treatment-responsive MDs. Therefore, we conducted transcriptomic analysis of bone marrow specimens to investigate the pathophysiology of treatment-resistant MDs. Transcriptomic analysis comparing treatment-resistant MDs and healthy control dogs identified 179 differentially expressed genes (DEGs). Pathway analysis using these DEGs showed that "Wnt signaling pathway" was a significantly enriched pathway. We further examined the expression levels of DEGs associated with Wnt signaling pathway and confirmed the upregulation of AXIN2 and CCND2 and the downregulation of SFRP2 in treatment-resistant MDs compared with treatment-responsive MDs and healthy control dogs. This alteration implied the activation of Wnt signaling pathway in treatment-resistant MDs. The activation of Wnt signaling pathway has been reported in human patients with myelodysplastic syndrome (MDS), which is characterized by dysplastic features of blood cells. Therefore, the results of this study implied that treatment-resistant MDs have distinct molecular pathological features from treatment-responsive MDs and the pathophysiology of treatment-resistant MDs might be similar to that of human MDS patients.

Diagnostic Significance Of Bone Marrow Examination Amongst The Patients With Abnormal Haematological Parameters.

Bone Marrow examination is considered to be the most indispensable diagnostic tool for the evaluation of many neoplastic and non-neoplastic haematological disorders. After an initial assessment of suspicious cases on abnormal laboratory parameters along with the clinical presentation of the patient marrow examination is finally required for diagnosis as well as management of many haematological malignancies as it offers a clear cytological as well as histological picture of Bone Marrow aspirate and biopsy respectively. The Objective was to evaluate the significance of Bone Marrow examination in patients with abnormal haematological parameters. A retrospective study conducted at the Pathology Department of Pak Emirates Military Hospital from (Jan-June 2022) On data from150 patients who were advised to undergo bone marrow examination due to abnormal lab parameters and peripheral smear findings after informed consent and approval from the ethics review committee, to find out the correlation of abnormal haematological parameters and aspirate findings which have led to a definitive diagnosis. Data comprising basic demographic variables (age, gender etc.), Abnormal Haematological Parameters (CBC), peripheral smear findings and Aspirate findings were analyzed using SPSS version 23.0. Out of 150 studied participants with abnormal haematological parameters 24 (16%) were diagnosed on bone marrow examination as acute leukaemia / Hodgkin's and Non-Hodgkin's lymphoma respectively, 13 (9%) cases of aplastic anaemia and Autoimmune HaemolyticAnaemia, 33 (22%)cases of hypersplenism, CML and multiple myeloma. While 22 (15%) cases were diagnosed with BME as CKD and reactive changes. Moreover, 22(15%) cases were found to have Iron Deficiency anaemia respectively. The study revealed that patients with abnormal haematological parameters should undergo bone marrow examination to ascertain the diagnosis for malignant as well as non-malignant conditions that could cause abnormal lab parameters.

Idiopathic multicentric Castleman's disease with TAFRO syndrome: a case report

Abstract Introduction/Objective Multicentric Castleman's disease(MCD) is a nonneoplastic lymphoproliferative disorder. Individuals affected by MCD exhibit systemic symptoms accompanied by the presence of multiple enlarged lymph nodes. MCD can be associated with human herpesvirus type-8, POEMS syndrome, or idiopathic (iMCD). TAFRO syndrome, a clinical subtype of MCD is a recently recognized disorder with an unclear cause, it comes with a combination of symptoms, namely thrombocytopenia, anasarca, fever, renal dysfunction, and organomegaly. This case report aims to shed light on the diagnostic challenges due to the rarity and nonspecific nature of TAFRO syndrome. Methods/Case Report We report a 30-year-old female who presented with night sweats, fever, fatigue, and cough. She had significant leucocytosis, lymphopenia, thrombocytopenia, anemia requiring transfusion, and elevated creatinine, CT showed ground glass opacities in the lungs and extensive lymphadenopathy. Axillary lymph node excisional biopsy revealed paracortical hyperplasia with increased vascularity, extensive polytypic plasmacytosis, and some follicular hyperplasia. On IHC staining it was positive for CD20, CD79a, PAX 5, and negative cyclin D1 for B lymphocytes. T lymphocytes were positive for CD3, CD5, CD2, CD7, CD4>CD8, Bcl2 and CD43. Plasma cells were composed mainly of IgG cells and some IgG4(IgG4/IgG <20%). HHV8 was negative. Flow cytometry showed 89% lymphocytes with a heterogenous population of T-cells and polytypic B cells. Serology revealed markedly elevated IL- 6, IL-2, VEGF CRP, and ESR while HIV and ANA were negative. Bone marrow biopsy was suggested. A final diagnosis of idiopathic multicentric castle man disease suggestive of TAFRO syndrome was made. The patient received steroids and is currently on siltuximab. Results (if a Case Study enter NA) NA Conclusion Our case fulfills at least four of the five major diagnostic criteria of TAFRO syndrome. It serves as a valuable addition to the scarce literature on TAFRO syndrome, providing insights into its diagnostic challenges

CD34+ Megakaryocytes Associate with Myelodysplastic Syndromes and Related Cytogenetic Abnormalities, but Not Other Hematological Disorders

Background: CD34 is a transmembrane phosphoglycoprotein that is a marker of hematopoietic stem cells and is used clinically to aid in enumeration of blast cells for identification of advanced myeloid neoplasms. Megakaryocytes are differentiated cells from the myeloid lineage that reside in the bone marrow and generally stain negative for CD34 (CD34-). However, CD34 positive (CD34+) megakaryocytes have been observed in hematological disorders such as myelodysplastic syndrome, myeloproliferative neoplasms, and acute leukemias. CD34+ megakaryocytes are proposed to be relatively specific for malignant hematologic conditions and have been reported to associate with a worse prognosis. However, the general clinical, biochemical, and cytogenic characteristics for bone marrow cases of CD34+ megakaryocytes versus CD34- megakaryocytes remains unclear. Objective: We sought to determine the clinical, biochemical, and cytogenetic characteristics associated with finding CD34+ megakaryocytes on bone marrow biopsies. Methods: We identified 281 independent, index bone marrow biopsy cases between 2011-01-01 and 2017-12-31 from Vancouver General Hospital, Canada that underwent CD34 immunohistochemistry at clinical request. The clinical, biochemical, and cytogenetic characteristics of patients were compared based on megakaryocytes being CD34+ vs CD34- on immunohistochemistry. Cases of CD34+ megakaryocytes were defined as having >5% of megakaryocytes staining CD34+, but sensitivity analyses were performed using different percentage cut-offs of 10, 30, and 50%. Results: Out of 281 cases, 134 had CD34+ megakaryocytes (58.2% male sex; mean age = 64.1 years [SD = 15.2 years]) and 147 had CD34- megakaryocytes (57.1% male sex; mean age = 60.0 years [SD = 16.6 years]). There was a significant difference in the distribution of diagnostic categories observed between cases of CD34+ versus CD34- megakaryocytes: myelodysplastic syndromes 35.1% (n=47) versus 21.8% (n=32), acute myeloid leukemias 20.9% (n=28) versus 21.1% (n=31), non-diagnostic etiology 17.9% (n=24) versus 14.3% (n=21), and myeloproliferative neoplasms 10.4% (n=14) versus 19.7% (n=29) (Figure A; Chi-square p-value=0.0004). Sensitivity analyses using different percentage cut-offs to define cases of CD34+ from CD34- megakaryocytes yielded similar results. The differences in biochemical characteristics between cases of CD34+ versus CD34- megakaryocytes were generally unremarkable. The median (IQR) for biochemical parameters between cases of CD34+ and CD34- megakaryocytes were hemoglobin 99 (28) versus 100 (34) g/L, mean corpuscular volume 94 (14) versus 93 (10) fL, neutrophil count 2.20 (3.68) versus 2.46 (3.63) x10 9/L, platelet count 98 (158) versus 112 (194) x10 9/L, and bone marrow blasts 7 (4) versus 3 (14)%. Lastly, there were notable trends in cytogenetic results associated with 90 cases with CD34+ versus 84 cases with CD34- megakaryocytes including: complex karyotypes for 15.6% (n=14) versus 6.0% (n=5), isolated deletion 5q for 7.8% (n=7) versus 1.2% (n=1), and/or isolated trisomy 8 for 5.6% (n=5) versus 2.4% (n=2). Similar cytogenetic results were observed when cases were restricted to only cases of CD34+ versus CD34- megakaryocytes with a diagnosis of myelodysplastic syndrome (Figure B). Conclusion: The presence of CD34+ megakaryocytes is more common in cases of myelodysplastic syndrome relative to other neoplastic hematologic disorders, but does not appear to help with discriminating between neoplastic and non-neoplastic hematological disorders ( e.g. non-diagnostic etiology). Cases with CD34+ megakaryocytes tend to associate with complex karyotype and deletion 5q abnormalities relative to cases with CD34- megakaryocytes.

A retrospective study of nonneoplastic and neoplastic disorders of the salivary glands.

The spectrum of major and minor salivary gland disorders varies widely. Epidemiological data on some injury categories are rare and often not up-to-date. This study aims to analyze epidemiological data using clinical, paraclinical, and histopathological parameters. Study was carried out for 5 years on the nonneoplastic and tumoral pathology of the salivary glands. Data were statistically analyzed using the appropriate parameters. Data analysis according to the biological behavior of the lesions revealed great heterogeneity. Statistically significant correlations were observed between the type of injury, age (P = .002) and gender (0.033). The environment of origin of the patients as well as the comorbidities reflected in most cases the nature of the process. Associations were also observed between the biological behavior of the lesions and the hemicranial topography (P = .019), the type of salivary gland (P = .024), and the surgical technique used (P < .001). Most cases were identified in the major salivary glands, often in the parotid. The most common diseases are represented by nonspecific chronic sialadenitis (nonneoplastic lesion), pleomorphic adenoma and Warthin tumor (benign tumors), mucoepidermoid carcinoma (malignant tumor), and squamous carcinoma (secondary tumor). They presented axial diameters between 2 to 95 mm. The most used curative technique was subtotal excision with facial nerve preservation. In conclusion, the study highlighted the main epidemiological aspects of salivary gland disorders. Some data agree with the specialty literature, and particular aspects are also observed. Therefore, this research is useful both in the medical and research fields.

Rosai-Dorfman disease of the breast: a clinicoradiologic and pathologic study

Rosai-Dorfman disease (RDD) is an uncommon histiocytic disorder typically involving lymph nodes and less frequently extranodal tissues. RDD involving the breast is rare and may clinically and radiologically mimic neoplastic and non-neoplastic disorders. We report seven patients with breast RDD, describe their clinicoradiologic and pathologic features, and discuss the differential diagnosis. Patients, ranging from 15 to 74 years of age, presented with unilateral and unifocal (5/7) or bilateral and multifocal (2/7) masses. RDD was either confined to the breast (6/7) or concurrently involved a lymph node (1/7). Masses ranged from 8 to 31mm, categorized as Breast Imaging-Reporting and Data System (BI-RADS) 4 (6/7) or 5 (1/7). All cases showed similar morphology with many large histiocytes displaying emperipolesis with associated fibrosis and dense lymphoplasmacytic infiltrate. The abnormal histiocytes co-expressed CD68/CD163, S100, OCT2, and Cyclin D1 (7/7), and were negative for CK AE1/AE3 (7/7), CD1a (7/7), and BRAF V600E (6/6). Flow cytometry (n=3), kappa/lambda in situ hybridization (n=5), and IgG4/IgG immunohistochemistry (n=1) did not reveal lymphoma or IgG4-related disease. No mycobacterial or fungal organisms were identified on acid-fast bacillus (AFB) and Grocott methenamine silver (GMS) stains (n=5). Three patients underwent complete excision and none recurred or progressed to systemic disease during follow-up (88-151 months). In summary, breast RDD should be included in the differential diagnosis of a mass-forming breast lesion. Histopathology with ancillary studies and clinicoradiologic correlation is essential for accurate diagnosis and optimal clinical management. Patients with RDD of the breast have an excellent prognosis after complete excision.

The Atlas of Non-neoplastic Disorders of the Endocrine System by Anthony J. Gill, Lori A. Erickson and Talia L. Fuchs, Series 5, Fascicle 13.

The Atlas of Non-neoplastic Disorders of the Endocrine System by Anthony J. Gill, Lori A. Erickson and Talia L. Fuchs, Series 5, Fascicle 13.

Hypoxia-inducible Factor-1α and mTOR as a Potential Therapeutic Target in Endometriosis: An Immunohistochemical Study.

We aim to study the immunohistochemical expression of both hypoxia-inducible factor-1α (HIF-1α) and mammalian target of rapamycin (mTOR) in endometriosis to provide new evidence for a targeted endometriosis therapy. This study comprised 106 endometriotic cases diagnosed clinically and histopathologically. The immunohistochemical method was done to determine the expression of HIF-1α and mTOR. Endometriotic glands showed significant cytoplasmic expression of both markers in patients with poor ovulation, severe endometriosis, and infertile for >2 years ( P <0.001). Also, patients with intense and worst pain show significant immunohistochemical expression of both markers ( P <0.001). There is a significant correlation between mTOR and HIF-1α expression in endometriotic tissue samples as P <0.001. Our data suggest that both mTOR and its downstream target HIF-1α transcription factor are both disrupted in patients with endometriosis, which is consistent with aberrant activation of these pathways and their possible contribution to the pathogenesis of endometriosis. These results could offer a promising novel opportunity to be blocked therapeutically. As new management options need to be refined in particular in severe cases and infertile patients with endometriosis, therefore future studies are warranted to investigate treating endometriosis with mTOR inhibitors; the latter are already in clinical trials in phase III and IV, treating solid tumors as well as non-neoplastic disorders.

Human Herpesvirus-8 Positive Multicentric Castleman’s Disease with Complete Response after Rituximab Monotherapy: A Case Report

Castleman’s disease is a rare non-neoplastic lymphoproliferative disorder of unknown origin. It is classified into unicentric or multicentric based on its anatomical distribution. Multicentric Castleman’s disease can be subdivided according to the presence of human herpesvirus-8 (HHV-8) infection. Castleman’s disease has a rare incidence, and HHV-8-positive multicentric Castleman’s disease is even rarer. There are several types of natural course for this disease, and the rapidly progressing type can lead to death within a few weeks, emphasizing the need for prompt diagnosis and treatment. We report a recent case from Korea, presenting with multiple lymphadenopathies, confirmed as HHV-8-positive multicentric Castleman’s disease through biopsy, and achieving complete response with rituximab monotherapy.

Expression and significance of cyclinD1, cyclin-dependent kinase4 and cyclin-dependent kinase inhibitor P27 in patients with non-neoplastic epithelial disorders of the vulva.

Non-neoplastic epithelial disorders of the vulva (NNEDV) are prevalent and refractory gynecological diseases. However, the underlying pathogenesis of these diseases remain unclear. The present study aimed to investigate the expression and significance of cyclin D1, cyclin-dependent kinase 4 (CDK4) and cyclin-dependent kinase inhibitor P27 (P27) in patients with NNEDV and provide a reference for clinical diagnosis and treatment. Normal vulvar skin samples from patients with perineum repair (control group, n=20) and skin samples from the vulvar lesions of patients with NNEDV (NNEDV group, n=36) were collected. Expression levels of cyclin D1, CDK4 and P27 were assessed in the samples using immunohistochemistry. The expression of each protein was evaluated based on the mean optical density (MOD). The MODs of cyclin D1 and CDK4 were significantly higher in samples of the three pathological types of NNEDV, namely squamous hyperplasia (SH), lichen sclerosus (LS) and mixed SH and LS lesions, compared with those of the control group. The MOD of P27 was lower in samples of the three pathological types of NNEDV than in the control group, although the difference was not statistically significant. No significant differences in the MOD of cyclin D1, CDK4 and P27 were detected among the three pathological types of NNEDV. The ratios of the MOD of cyclin D1 and CDK4 in the prickle cell layer to those in the basal cell layer were significantly higher in the NNEDV group than in the control group. However, the ratio of the MOD of P27 in the prickle cell layer to that in the basal cell layer exhibited no significant difference between the NNEDV and control groups. NNEDV has the potential for malignant transformation. The occurrence and development of NNEDV may be associated with the acceleration of cell proliferation, in which cyclin D1, CDK4 and P27 contribute to regulation of the cell cycle. Therefore, cyclin D1, CDK4 and P27 may be potential targets in the development of new clinical therapeutic drugs for patients with NNEDV.

Naringenin ameliorates Cyclophosphamide-induced nephrotoxicity in experimental model

Cyclophosphamide (CP) is widely described in the management of several nonneoplastic and neoplastic disorders. Renal damage is the most reported toxic effect of CP in clinical practice.Our study aimed to evaluate the effect of Naringenin (NG) in attenuating renal damage induced by CP in an experimental model.A total of 32 rats were divided into four groups (n = 8): negative control: rats fed on a basal diet, positive control: rats injected intraperitoneally with CP 50 mg/kg of body weight/day, NG 100: rats treated with NG 100 mg/kg/day body orally with concomitant administration of CP as described before, and NG 200: rats treated with NG 200 mg/kg/day body orally daily + CP. At the end of the experimental protocol (21 days), blood creatinine and urea levels were measured. The antioxidant activities and lipid peroxidation products were measured in the renal tissues as indicators of oxidative damage. Histopathological examination and immunohistochemistry staining were also performed on renal tissues.Coadministration of NG along with CP significantly (p < 0.001) improved the renal function and antioxidant capacities compared with positive control animals. Furthermore, histopathological, and immunological examination of renal tissue confirmed the protective effect of NG against CP-induced nephrotoxicity.The current study showed that NG has the potential to protect CP-induced renal damage, which may be beneficial for further studies and the design of NG analogs to be useful in clinical practice against CP-induced nephrotoxicity.

An Update on the Role of Immunohistochemistry in the Evaluation of Pancreatic/Liver/Gastrointestinal Luminal Tract Disorders.

Immunohistochemistry serves as an ancillary diagnostic tool for a wide variety of neoplastic and nonneoplastic disorders, including infections, workup of inflammatory conditions, and subtyping neoplasms of the pancreas/liver/gastrointestinal luminal tract. In addition, immunohistochemistry is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the pancreas, liver, and gastrointestinal luminal tract. To highlight an update on the role of immunohistochemistry in the evaluation of pancreatic/liver/gastrointestinal luminal tract disorders. Literature review and authors' research data and personal practice experience were used. Immunohistochemistry is a valuable tool, assisting in the diagnosis of problematic tumors and benign lesions of the pancreas, liver, and gastrointestinal luminal tract, and also in the prediction of prognosis and therapeutic response for carcinomas of the pancreas, liver, and gastrointestinal luminal tract.

HISTOPATHOLOGICAL STUDY OF LESIONS OF ANAL CANAL

Background. Diverse diseases including congenital anomalies like Hirschsprung disease, anorectal agenesis, infections like tuberculosis, parasitic infestations, inammatory disorders like Crohn's disease ulcerative colitis, and neoplasms like adenomas, adenocarcinomas, squamous cell carcinoma etc, involve the anal canal. Despite its short length, the anal canal produces a variety of tumor types reecting its complex anatomic and histologic features (WHO). Majority of these disorders present with common symptoms like constipation, per rectal bleeding, altered bowel habits and difculty in defecation. The study was undertaken with the aim of a Aim: nalysing the histopathological lesions of anal canal with clinicopathological corelation. Total 116 lesions affecting anal canal over Materials and methods: a period of January 2013 to June 2017(4.5 years) were included in this study. Demographics of patients, presenting symptoms and pathologic features were recorded. Out of 116 Results: lesions, 106 were nonneoplastic, greatly outnumbering the eight neoplastic lesions. Anal stula was the most common lesion accounting for 49 cases. Most common age group affected was 31-40 years. Conclusion: Histopathological examination of every anal lesion is important since clinical presentation of neoplastic and nonneoplastic disorder is same. Rare entities like anal gland carcinoma can be diagnosed only on histopathology

Slowly Expanding 18 F-FDG PET-Positive Irregular Opacities in the Lung Due to Diffuse Lymphoid Hyperplasia Preceding Rheumatoid Arthritis.

Pulmonary diffuse lymphoid hyperplasia (DLH), a nonneoplastic lymphoproliferative disorder (LPD), is extremely rare, and no PET/CT findings have been reported for pulmonary DLH. We observed slowly expanding irregular opacities with 18 F-FDG accumulation (SUV max , 3.64) in the right lower lobe of a 51-year-old asymptomatic man. The patient underwent video-assisted thoracoscopic biopsy on suspicion of malignant lesions. Histologically, no neoplastic cells were present, and the lesion was consistent with DLH. Six months later, the patient developed rheumatoid arthritis. DLH should be considered in the differentiation of PET-positive irregular opacities, even in the absence of known immune abnormalities.

Analysis of the Prevalence of Canine Splenic Mass Lesions in Republic of Korea via Histopathological Diagnosis with Immunohistochemistry.

The histopathological diagnosis of canine splenic mass lesions is crucial for prognostication. However, thus far, no study has been conducted on the histopathology of canine splenic mass lesions in Republic of Korea. Herein, the prevalence of splenic diseases was analyzed in 137 canine splenic mass lesions via histopathological diagnosis, and the microscopic pattern associated with each disorder was described. Immunohistochemistry was performed for CD31, CD3, PAX5, Iba1, and C-kit for a more accurate diagnosis of splenic tumors. The proportion of non-neoplastic disorders, including nodular hyperplasia (48.2%, n = 66) and hematoma (24.1%, n = 33), was 72.3%. Splenic tumors, including splenic hemangiosarcoma (10.2%, n = 14), splenic lymphoma (nodular and diffuse types, 8.0%, n = 11), splenic stromal sarcoma (7.3%, n = 10), myelolipoma (1.5%, n = 2), and mast cell tumors (0.7%, n = 1), accounted for 27.7% of cases. The results of this study will aid veterinary clinicians in communication with pet owners about prognoses, recommendations for splenectomy, and subsequent histopathological diagnoses. This study will facilitate further investigations with more detailed comparisons of splenic mass lesions between small- and large-breed dogs.

Mast cell evaluation in gastrointestinal biopsies: should we be counting? A critical review and practical guide for the surgical pathologist.

Mast cells are residents of the tubular gastrointestinal (GI) tract, where they play an important role in host defence and other vital functions. Dysregulation of mast cells has been implicated in the pathogenesis of several neoplastic, inflammatory, and functional disorders, some of which may manifest with GI symptoms. Surgical pathologists must therefore confront when and how to evaluate GI biopsies for mast cells, and whether such decisions should be based on morphologic criteria, clinical context, or direct request from clinical colleagues. The pathologist's role in evaluation of mast cell infiltrates is best defined in the diagnosis of systemic mastocytosis, where the utility of morphologic assessment coupled with ancillary studies is well established. In contrast, in nonneoplastic mast cell disorders such as mast cell activation syndrome, irritable bowel syndrome, or so-called 'mastocytic enterocolitis', a role for histopathology, if any, is controversial. Despite this, pathologists have seen a sharp increase in requests for mast cell quantification in the latter setting, despite these requests not being supported by published evidence. Moreover, what constitutes a 'normal' number of mast cells in a luminal GI biopsy is not well established. As a result, there is considerable variation in how these requests are handled in practice. This review evaluates and summarizes the published evidence relating to mast cell evaluation in endoscopic GI biopsies in various clinical scenarios, with a goal of providing practical, evidence-based guidance for the surgical pathologist when approached with requests for mast cell quantification in GI biopsies.

Normal Bone Marrow and Non-neoplastic Systemic Hematopoietic Disorders in the Adult.

This article provides an overview of the imaging appearances of normal adult bone marrow with an emphasis on magnetic resonance imaging. We also review the cellular processes and imaging features of normal developmental yellow-to-red marrow conversion and compensatory physiologic or pathologic red marrow reconversion. Key imaging features that differentiate between normal adult marrow, normal variants, non-neoplastic hematopoietic disorders, and malignant marrow disease are discussed, as well as posttreatment changes.

Advances in Bone Marrow Imaging: Strengths and Limitations from a Clinical Perspective.

Conventional magnetic resonance imaging (MRI) remains the modality of choice to image bone marrow. However, the last few decades have witnessed the emergence and development of novel MRI techniques, such as chemical shift imaging, diffusion-weighted imaging, dynamic contrast-enhanced MRI, and whole-body MRI, as well as spectral computed tomography and nuclear medicine techniques. We summarize the technical bases behind these methods, in relation to the common physiologic and pathologic processes involving the bone marrow. We present the strengths and limitations of these imaging methods and consider their added value compared with conventional imaging in assessing non-neoplastic disorders like septic, rheumatologic, traumatic, and metabolic conditions. The potential usefulness of these methods to differentiate between benign and malignant bone marrow lesions is discussed. Finally, we consider the limitations hampering a more widespread use of these techniques in clinical practice.