Immunohistochemical analysis of myeloperoxidase expression in cutaneous leucocytoclastic vasculitis.

Myeloperoxidase (MPO) is a pro-oxidant enzyme mainly found in the azurophilic granules of neutrophils. It not only displays a key role in the intracellular microbial killing process but also contributes to the extracellular clearance of several pathogens. This study aimed to detect MPO in cutaneous leukocytoclastic vasculitis (LCV) using immunohistochemistry. We retrospectively collected 22 confirmed cases of skin LCV diagnosed in our pathology department over 11 years (2012-2023). Immunohistochemistry was performed using anti-myeloperoxidase antibody (Leica clone 59A5) on the LeicaBond MAX automated system, following manufacturer's instructions. Two pathologists assessed immunohistochemical staining, scoring intensity as weak (+), moderate (++), or strong (+++). Patients' mean age was 56.9 years, with a male-to-female ratio of 1.18. Pathologically, vasculitis involved small blood vessels in all cases. Immunohistochemical analysis showed granular positive MPO staining in 59.1% of cases. Staining intensity was weak in 46.15%, moderate in 46.15%, and strong in 7.69%. Staining was patchy in 84.62% and diffuse in 15.38% of cases. MPO expression, detected in 59.1% of cutaneous LCV tissues, exhibited a patchy and peri-vascular distribution. It holds potential as a diagnostic marker for patients with early or minor histological changes.

Prognostic significance of E-Cadherin and B-Catenin in non-muscle invasive bladder cancer.

Non muscle invasive bladder cancer (NMIBC) has unpredictable outcomes with a variable risk of recurrence and progression. Many clinic-pathological prognostic factors have been identified but remain insufficient, raising the need to investigate new biomarkers. The aim of our study was to assess the prognostic value of the immunohistochemical (IHC) markers E-Cadherin and B-Catenin in NMIBC. All cases of NMIBC were collected between 2008 and 2013. IHC analysis was performed using E-Cadherin and B-Catenin. Reduced or loss of E-Cadherin expression was assessed as abnormal. Only cases with B-Catenin intense membranous staining were considered normal. A correlation was found between abnormal E-Cadherin expression and stage (p = 0.001), grade (p = 0.0000000), recurrence (p = 0.0000000), progression (p = 0.01), recurrence-free survival (p = 0.00000001), and progression-free survival (p = 0.01). A statistically significant association was found between B-Catenin and stage (p = 0. 05), grade (p = 0.02), and recurrence (p = 0.02). The abnormal expression of these markers could help to identify a high-risk subgroup of NMIBC that might benefit from either more accurate follow-up or more aggressive treatment.

Comparative expression profile of CD10 and cyclin D1 in cutaneous histiocytofibroma and dermatofibrosarcoma.

Dermatofibrosarcoma protuberans (DFSP) and histiocytofibroma (HF) are two rare fibrohistiocytic tumors, with some overlapping pathologic features. Immunohistochemistry is very useful in these cases. CD34 is a commonly used marker. However, the increasing cases of CD34 negative DFSP make it pressing to test other immunohistochemical markers that could help in the differential diagnosis. DFSP is known to harbor COL1A1-PDGFB rearrangement. Tumors in the differential diagnosis of DFSP usually lack this molecular signature. Recent studies suggested the interaction of PDGFB and PDGF receptor b with various signaling pathways, including the Akt-mTOR pathway. Cyclin D1, one of the oncoproteins activated in this pathway, may represent a promising useful biomarker in the differential diagnosis. On the other hand, CD10 expression in specialized mesenchymal skin cells, and especially in fibrohistiocytic skin tumors has been reported, which raises the interest of using this biomarker in HF and DFSP. In this study, we aimed to compare the expression of CD10 and cyclin D1 in 15 cases of DFSP and 15 cases of HF and discuss their potential contribution in the differential diagnosis.

Chronic gastritis classifications.

Chronic gastritis are inflammatory diseases of the gastric mucosa whose diagnosis depends on  pathological examination. They are frequent and cover a significant part of the daily activity of pathologists. Their origin is often infectious, particularly by Helicobacter Pylori. Several classifications of chronic gastritis were proposed but in order to achieve standardization in the drafting of pathological reports of gastric biopsies, pathologists currently following the recommendations of the revisted Sydney System. OLGA (Operative Link for Gastritis Assessment) and OLGIM (Operative Link for Gastritis Intestinal metaplasia Assessment) stages are increasingly used since they allow the clinicians to select patients with « high risk ¼ chronic gastritis, which require special monitoring. The aim of this paper was to perform a review of the different classifications of chronic gastritis currently available to pathologists.

Mixed tumor of the kidney.

Mixed epithelial and stromal tumour (MEST) of the kidney, is a recently recognized and rare entity .We herein reported the case of a 56 years old post-menopausal woman who presented with right abdominal pain. Her physical examination was unremarkable. Ultrasonography revealed the presence of a right cystic renal mass in the interpolar region extending into the pelvis. The tumor was considered Bosniak 4 category and a right nephro-ureterectomy was performed. The histological examination of the tumor revealed a mixed tumor with both epithelial and stromal pattern.

Autoimmune gastritis: assessment of OLGA and OLGIM staging systems.

BACKGROUND: Autoimmune gastritis present a risk of cancer related to atrophy and intestinal metaplasia. Two recent classifications OLGA (Operative Link on Gastritis Assessment) and OLGIM (Operative Link on Gastritic Intestinal Metaplasia assessment) have been proposed to reveal the high progressive risk forms (stages III and IV). AIM: To evaluate the OLGA and OLGIM staging systems in chronic autoimmune gastritis. METHODS: A descriptive single institution study of 30 cases of autoimmune gastritis. was performed over a 4-year period. The revaluation of atrophy and intestinal metaplasia, of gastric antrum and corpus, allowed to identify respectively the stages of OLGA and OLGIM systems. RESULTS: Our autoimmune gastritis were at high-risk stages in 26,5% of cases  according to two classifications. 95% of low-risk gastritis acoording to OLGA staging presented moderete to severe corpus atrophy. A significant association was present between high-risk gastritis according to OLGA staging and neuroendocrine hyperplasia. Both OLGA and OLGIM systems showed a highly significant positive correlation between them with a mismatch at 2%. CONCLUSIONS: The OLGA and OLGIM staging systems in autoimmune gastritis, allow probably selection of high risk forms of chronic gastritis requiring convenable care.

A Challenging Cutaneous T-Cell Lymphoma.

Cutaneous peripheral T-cell lymphomas not otherwise specified (CPTL-NOS) are rare neoplasms accounting for just 2% of cutaneous peripheral T-cell lymphomas (CPTL). Only very few case series have been reported. They represent a phenotypically and prognostically heterogenous group of CPTL that do not fit into any of CPTL well-defined subtypes. The authors report a case of a 64-year-old man with simultaneous plaque-like lesions and disseminated nodules growing rapidly on the face, trunk, and extremities over a 6-month period. There was no a history of preceding patches, erythematous plaques, rash, or pruritic lesions. These lesions were extending over 80% of the skin surface. Histopathologic analysis revealed dense diffuse infiltrates composed of mostly medium-sized to large lymphoid cells throughout the entire dermis without epidermotropism. Neoplastic cells were atypical with markedly pleomorphic nuclei. Immunohistochemistry showed that the tumor cells were positive for CD3, CD4, and CD5 with a loss of CD7. They were negative for CD20, CD8, CD56, CXCL13, PD1, TIA-1, granzyme-B, perforin, CD25, and CD30. The proliferative fraction was low, with MIB-1 labeling less than 10% of cells. The authors diagnosed the patient with primary CPTL-NOS. Despite the rarity of these tumors, clinicians as well as dermatopathologists and pathologists should be familiar with these rare CPTL especially because most of these lymphomas have an aggressive behavior and exhibit an unfavorable prognosis.

A round cell sarcoma of the bladder following radiotherapy: A case Report.

Sarcomas are uncommon and extremely aggressive malignancies. Sarcomas of the bladder are exceedingly rare. We report the case of 67-year-old female patient having had 20 years ago a total hysterectomy with bilateral adnexectomy followed by adjuvant external radiotherapy to an undifferentiated uterine sarcoma, was presented with hematuria. An abdomino-pelvic Computed Tomography (CT) Scan was done showing a 5 cm budding lesion of the bladder floor. An anterior pelvectomy with external urinary diversion was undergone. The histological examination showed a high grade urothelial carcinoma infiltrating the muscle with a sarcomatoid component.

Unilateral pseudouveitis revealing a pancreatic neuroendocrine carcinoma: A case report.

Neuroendocrine tumors are a heterogeneous group of tumors with a wide range of malignant potential that tend to have a relative prolonged course. These tumors infrequently metastasize to the orbit. To the best of our knowledge, ocular metastases from pancreatic neuroendocrine tumors (PNETs) have never been reported in the literature. We report the case of a 61-year-old man who presented with progressive deterioration of general condition with unilateral recurrent episodes of non-granulomatous panuveitis of the left eye related to a choroidal metastasis. Radiological imaging and histopathological analyses led to the diagnosis of metastatic pancreatic neuroendocrine carcinoma as the primary tumor. Choroidal metastases from neuroendocrine tumors are extremely rare, but compromise patients' well-being because of visual impairment. Uncommonly, these metastases can be the first manifestation of unknown tumors, warranting further investigations to detect the primary cancer.

A remarkable concept of learning in times of educational confinement Social media and pathologist.

Social media are inevitably becoming part of our lives. The increasing popularity of these platforms revolutionized communication among healthcare workers and has irrevocably changed the terms of classic learning models. Pathologists all over the world are very active on social media making it a new pedagogical paradigm in pathology education. A virtual community of pathologists is constantly present especially on Twitter and Facebook for sharing and discussing interesting cases, reporting original scientific researcher's results, or simply energizing our field. Tunisian pathologists are not taking advantage of these platforms, some do not master the use of social media, others are reluctant about their use in the health field. However, it is of crucial importance for us Tunisian pathologists, especially in these times of social distancing due to SARS-COV2 pandemic, to join this virtual community and implement new ways of learning. This article aimed primary to assess the popularity of these platforms as a pedagogic tool among Tunisian pathologist. Secondly, we introduced the basic use and rules of social media, benefits and potential risks, and to provided tips for effective social media use in pathology.

EpCAM (MOC-31) - immunohistochemical expression in papillary thyroid carcinoma and non invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP).

INTRODUCTION: Ep-CAM, is a cell adhesion glycoprotein located on the basolateral cell membrane surface and in the cytoplasm of most normal epithelial cells. It has also been described to be expressed in several malignancies such as lung, digestive, prostate and renal carcinomas suggesting it has a potential role in carcinogenesis.  In thyroid carcinoma, Ep-CAM expression has rarely been studied especially in papillary thyroid carcinoma. OBJECTIVE: We sought to describe and compare the immunohistochemical expression of MOC31 in papillary thyroid carcinoma and in non invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). METHODS: We have retrospectively collected 33 cases of PTC diagnosed in the pathology department of the Security forces hospital during a period of 13 years (2008-2021). We have microscopically reviewed all cases and reclassified 9 of 33 cases as NIFTP.  An immunohistochemical  automated study have been performed with MOC-31 antibody.  The immunostaining was considered positive when it was membranous and/or cytoplasmic. The intensity of staining was scored as weak (score 1), moderate (score 2), and strong (score 3). We have used an immunoscore for assessing level of expression of MOC31 as follows: 0 for <5% of positive cells, 1 for 5-30%, 2 for 31-50%, 3 for 51-70%.The total score resulted by summing the percentage score with the intensity score; the final score was varying from 0 to 7, considered low between 1-4 and high 5-7. RESULTS: The mean age of patients was 45,2 years-old for PTC cases and 48,1 years-old for NIFTP cases. A net female predominance was found in both groups (male to female ratio of respectively 0,4 and 0,3). MOC31 expression was found in 19 cases of PTC with a percentage of positive cells varying from 5 to 90%. Percentage of positive cells was variable from 5 to 90%. The immunoscore for positive cells was: 0 in 5/24cases, 1 in 4/24cases, 3 in 9/24cases and 4 in 6/24cases. The intensity of staining was assessed score2 (moderate) in 8 cases and score 3 (high) in 7cases (Figure1-2). Final MOC31 staining score was low in 37,5% (9/24) and high in 62.5% (15/24). Patients with advanced pt2-pt3 stages mostly showed high score of MOC31 staining (61,5%).One case was associated with lymph node involvement and was of a high score. 6 cases showed vascular invasion and was of high MOC31 score. MOC31 was expressed in all NIFTP cases with variable proportion of positive cells (5%-80%). The immunoscore for positive cells was: 0 in 1/9cases, 1 in 2/9cases, 2 in 3/9cases, 3 in 1/9cases and 4 in 2/9cases. The intensity of staining was assessed score 1 (weak) in one case, score 2 (moderate) in 6 cases and score 3 (high) in one case (Figure3-4). The final combined score was low in 66,7 (6/9) and high in 33,3% (3/9). CONCLUSION: Our study revealed different immunohistochemical profile of MOC31 in benign and malignant tumors. It has somewhat a diffuse and marked staining in the first group.  The changes of MOC31 location as well as its score of staining in PTC and NIFTP could hence be helpful in the differential diagnosis. Our findings also support the potential prognostic value of this molecule that deserves further investigations.

SARS-CoV-2 vaccine induced Sweet syndrome : a case report.

Sweet syndrome (SS), also known as acute febrile neutrophilic dermatosis is a rare cutaneous disorder characterized by specific clinical, biological and microscopic findings. Although the exact cause of SS is still unknown, it may be triggered by infections, malignancies and drugs but also occurring after vaccinations such as bacille calmette guerin vaccination and influenza vaccine. While the recently discovered SARS COV2 vaccines are almost safe, many cutaneous and extracutaneous minor adverse effects are reported. We herein describe the fourth case of Sweet Syndrome induced by SARS-COV2 vaccine.

[Pseudo tumoral gastric amyloidosis: a case report]. / Amyloïdose gastrique pseudo tumorale: a propos d'une observation rare.

BACKGROUND: Amyloidosis is an abnormal extracellular deposition of insoluble proteins, which is associated with an involvement of the gastrointestinal tract in 50 to 70% of cases. In primary amyloïdosis (light chain amyloïdosis), localized gastric involvement is a rare finding which can mimick malignancy. AIM: To elucidate the clinical, histological and therapeutic features of pseudo tumoral gastric amyloidosis via a rare report along with a review of related literatures. OBSERVATION: We report the case of a 56-year-old man, admitted with upper digestive outlet obstruction. Linitis plastica with lymph node involvement was suspected by gastroscopy, barium meal and endoscopic ultrasonography but was not confirmed by gastric biopsies. The patient was treated with total gastrectomy with lymph node dissection. Pathological examination demonstrated gastric and lymph nodes amyloidosis and no malignant tumor was found. CONCLUSION: We propose that amyloidosis should be considered in the differential diagnosis of gastric tumors.

Prognostic value of CD44s expression in urothelial bladder tumors.

Urothelial bladder carcinoma (UBC) includes a large group of malignancies with a variable clinical behavior. Despite remarkable developments in recognition of bladder carcinogenesis and prognostic factors, the recurrence rate is still high. Thus, identification of novel biomarkers involved in tumor cell invasion and metastatic dissemination is a constant challenge. AIM: To assess the prognostic impact of CD44 standard (CD44s) expression in UBT. METHODS: We assessed the immunohistochemical expression of CD44 in 38 samples of endoscopically resected UBT. Only membranous staining was considered positive. We analyzed topographic distribution of CD44s staining. Correlation of CD44s expression, clinicopathological features and disease progression was analyzed by Chi2 and Fisher tests. Kaplan-Meier analysis was used to investigate CD44s prognostic value. RESULTS: The mean age of patients was 61,24 years with male to female ratio of 18/1. CD44s expression was positive in 33 cases (87%). There was no significant correlation between CD44 expression and the parameters:  age, gender, tumor size, focality, tumor site, stage, recurrence and tumor progression. CD44s loss of expression is, nevertheless, correlated with a high tumor grade. Topographic distribution of CD44s staining was associated with focality, grade and stage. Basal/parabasal staining expanded to the tumor layers in homogeneous "laminate" pattern used to be of better prognosis, compared to the heterogeneous "islets" or "dispersed" pattern. CONCLUSIONS: Our results highlighted the prognostic value of CD44 expression in UBT. Focusing especially on staining pattern offers a better understanding of bladder carcinogenesis mechanisms.

[Descriptive epidemiology of extrapulmonary hydatid cysts: a report of 265 Tunisian cases]. / Profil epidémiologique descriptif des kystes hydatiques extra pulmonaires: a propos d'une série tunisienne de 265 cas.

BACKGROUND: Hydatidosis is a parasitic endemic disease in Tunisia. The liver and lung are the most common sites of involvement; however, it can develop anywhere in the body. AIM: The aim of the present study was to analyse the epidemiological features of extrapulmonary hydatid cysts and compare our results with those reported in literature. METHODS: A retrospective study of 265 extrapulmonary hydatid cysts collected over the 18-year period from 1990 to 2007 was undertaken. RESULTS: There were 101 male and 164 female patients (sex ratio M/F = 0.61) ranging in age from 2 to 84 years (mean age = 38.7). In our series, hydatid cysts involved mainly the kidney (24.1%), the central nervous system (22.6%), the liver (19.6%) and the spleen (11.3%). The other less frequent sites included the peritoneum (n = 9), heart (n = 9), bone (n = 6), adrenal gland (n = 4), epiploon (n = 4), orbit (n = 4), ovary (n = 3), prostate (n = 2), bladder (n = 2), breast (n = 2), Douglas' cul-de-sac (n = 2), diaphragm (n = 1), testis (n = 1), broad ligament (n = 1), mediastinum (n = 1), nasal cavity (n = 1), soft tissue (n = 1), abdominal wall (n = 1), parotid gland (n = 1), psoas muscle (n = 1), synovia (n = 1), thymus (n = 1) et le pancreas (n = 1). CONCLUSION: In contrast to literature, our results show that hydatid cysts of the kidney and of the central nervous system are more frequent than hepatic location which occupies the 3rd rank.

[Central nervous system dysgerminoma: a clinicopathological study of 3 cases]. / Dysgerminomes du système nerveux central: étude anatomo-clinique de 3 cas.

BACKGROUND: Intracranial germ cell tumors are rarely seen and typically localize in the pineal or suprasellar region. The largest category of germ cell tumors is dysgerminoma. AIM: to describe clinicopathological features and immunohistochemical profile of dysgerminomas. CASE REPORT: We report three cases of central nervous system dysgerminomas. There were two young women and a man who were 6, 11 and 23-year-old. They presented with symptoms of insipidus diabetes (n=3) with association to visual field defects in the third case. Radiological findings showed a supra seller lesion in two cases. Double localization in the pineal and suprasellar regions was seen in the third case. Histologic examination and immunohistochemical study of surgical specimen were consistent with primary central nervous system dysgerminoma.