CD34 Positivity Research Articles

Atypical Presentation of Spindle Cell Lipoma in a Young Male with a History of Malignant Melanoma

Spindle cell lipoma (SCL) is a benign adipocytic tumor usually found in the subcutis of the posterior neck, upper back, and shoulder, predominantly in middle-aged males. This case report describes an atypical presentation of SCL in a 26-year-old male with a history of malignant melanoma. The patient presented with an erythematous plaque with central hyperpigmentation on the right upper arm, an uncommon location and presentation for SCL. Histopathological examination revealed an atypical myxoid spindle cell neoplasm with CD34 positivity and an overlying mildly atypical compound melanocytic nevus. The unusual clinical and histological features, combined with the patient’s melanoma history, complicated the differential diagnosis, which included dermatofibrosarcoma protuberans (DFSP) and solitary fibrous tumors (SFTs). A wide local excision with 2 cm margins was performed, and subsequent pathology confirmed clear margins, supporting the diagnosis of SCL. This case highlights the importance of including SCL in the differential diagnosis of CD34-positive spindle cell tumors, even when clinical and histological presentations are atypical, and underscores the need for thorough histopathological evaluation and a broad differential diagnosis in patients with a history of melanoma.

Left Ventricular Apical Aneurysm in a Dog—A Case Report

The cadaver of a 16-year-old mixed-breed male dog was presented to the Faculty of Veterinary Medicine of IULS, Romania, after having been euthanized in a private practice at the owner’s request following acute cardio-respiratory failure. The necropsy revealed a left ventricular apical aneurysm with a bulging fibrous sac measuring about 0.7 cm/0.3 cm. The lesion involved all three structures of the cardiac wall, with mineralization areas and neovascularization. Immunohistochemistry showed strong positivity for desmin and weak positivity for CD-31 in the cardiac muscle fibers, positivity for α-sma in the smooth muscle cells of the vascular walls and positivity for vimentin in the cardiac stroma. MMP-2 and MMP-9 showed strong expression in the cardiomyocytes, whereas TIMP-1 showed positive immunoexpression only in the Eberth’s lines. To the authors’ knowledge, left ventricular apical aneurysm has only been reported once in dogs.

TMIC-45. CYTOMEGALOVIRUS PP65 ANTIGEN EXPRESSION FOLLOWING PP65-SPECIFIC DENDRITIC CELL VACCINATION IN MATCHED PRIMARY AND RECURRENT GLIOBLASTOMA SPECIMENS

Abstract BACKGROUND Human cytomegalovirus (HCMV) expression in glioblastoma (GBM) has been corroborated by multiple independent laboratories. HCMV genes have been directly linked to GBM cell proliferation, invasion, and angiogenesis. The HCMV tegument protein pp65 has served as a tumor-specific antigen in serial pp65 RNA-pulsed autologous dendritic cell (DC) vaccine trials. Here we report pp65 expression in matched primary and recurrent GBM samples from those trials following pp65-DC vaccination. METHODS Paired GBM specimens were collected from patients receiving pp65-DC vaccines according to ATTAC and ATTAC-GM clinical trials (NCT00639639). Of 23 treated patients, 9 cases were available for analysis. Formalin-fixed paraffin-embedded specimens were mounted on glass slides and stained for pp65 via immunohistochemistry (IHC). CD31 served as a control for tissue quality and to investigate the role of pp65 co-staining in the tumor perivascular niche. RESULTS Of 9 available cases, 5 were excluded due to poor tissue quality/absent CD31 staining on aged slides. Among the remaining four cases, three showed pp65 staining in non-vascular and perivascular areas within both primary and recurrent samples. However, recurrent specimens of these positive cases demonstrated a clear reduction in both intensity and distribution of pp65 staining within non-vascular regions but retained a strong positivity within the perivascular space. The fourth case showed absent pp65 staining and only weakly positive CD31 staining in both primary and recurrent specimens. Necrotic areas within pp65-positive slides showed minimal to no pp65 staining. CONCLUSIONS This study confirms HCMV pp65 expression in both primary and recurrent GBM following pp65-DC vaccination, with an interesting phenomenon of retained pp65 expression specifically in the perivascular niche. These findings support the role of HCMV in GBM angiogenesis and tumor progression as well as mechanisms of immune evasion following single antigen vaccine platforms. Our study reinforces the importance of tissue quality for proper HCMV detection in GBM.

Microvenular hemangioma located in the breast: a case report

Abstract Microvenular hemangioma (MVH) is a rare, benign type of hemangioma that typically presents as a solitary, slow-growing, red-to-violaceous asymptomatic papule, plaque, or nodule. It most commonly locations of the lesions on the limbs and trunk, with no prior reports of MVH confined to the breast. We present the first reported case of multiple MVH confined to the breast in a 17-year-old female patient. The case is notable for its unique and atypical clinical features. Diagnosing MVH is challenging and requires routine pathological and immunohistochemical staining. Histological testing revealed typical features of MVH, irregularly branched small or medium vascular interstitial spaces lined with benign endothelial cells and positivity for CD34 and CD31. This case emphasizes the need to consider MVH in the differential diagnosis of breast vascular lesions, particularly in young patients. It also underscores the importance of histological and immunohistochemical analyses for an accurate diagnosis.

Reevaluating hybrid neurofibroma/schwannoma: Predominance of schwannoma features despite CD34 positivity and initial neurofibroma diagnosis.

Schwannomas consist of both high-cellularity regions (Antoni A area) and hypocellular regions (Antoni B area) in histopathological findings. Neurofibromas characteristically consist of CD34 positive spindle cells with thin, wavy, nuclei and wavy collagen bands. Previous reports have described segments of schwannomas with neurofibroma features as hybrid tumors, although hybrid tumors were diagnosed based on partial CD34 positivity in many previous reports. On the other hand, the Antoni B area of some schwannomas was reported to be positive for CD34. Therefore, the definition of a hybrid tumor has not been clear. The objective of this study was to determine whether only CD34 positive findings in schwannomas could be used to define a hybrid tumor. In the analysis of our patient with schwannomatosis caused by a novel LZTR1 germline mutation, part of the tumor had CD34 positive hypocellular regions. These regions contained no thin, wavy, nuclei, indicating an Antoni B area. Laser microdissection was used to investigate the genetic background and differences in molecular mechanisms between CD34 positive and CD34 negative regions. All mutations identified in CD34 positive regions were also found in CD34 negative regions. Our data could not clear the genetic background of Antoni B which was CD34 positive area. We then reviewed the pathologies of 66 sporadic schwannomas. Histopathological examinations of all schwannomas revealed the absence of thin, wavy, nuclei and wavy collagen bands, and no hybrid tumors were found in any of the cases. Ten of 66 patients were randomly selected for CD34 immunostaining and positivity was found in all cases. Our data suggest that it is difficult to distinguish schwannomas by staining for CD34 alone, as Antoni B areas can also be positive for CD34. Therefore, CD34 staining alone should not be used to diagnose hybrid tumors in patients with schwannomas.

Superficial Papular Neuroma: Two Cases of a Distinctive Dermal Neoplasm.

Superficial papular neuroma is a rare cutaneous spindle cell lesion, with only 5 cases reported in 2 studies. We document 2 additional cases in a 45-year-old man and a 43-year-old woman (the first case identified in a woman). Clinically, superficial papular neuromas appear as a single, non-specific papule on the head, neck, or back. Histologically, these lesions are within the papillary and superficial reticular dermis, with nerve-like structures composed of bland spindle-shaped cells intersecting normal tissue with mild reactive acanthosis. The cells are SOX10 positive with neurofilament protein staining multiple axons within. The nerve-like structures in this study were occasionally surrounded by a thin rim of CD34 positivity, with no epithelial membrane antigen staining, similar to normal sensory neurons. Superficial papular neuroma are rare benign neoplasms with no reports of recurrence, even when incompletely excised.

Soft-tissue keratocyst: report of 3 new cases from Brazil.

To describe the clinicopathological features of 3 new cases of soft-tissue keratocyst (STK) of the buccal mucosa from Brazil. Clinical data from 3 patients diagnosed with STK were obtained from the archives of the Laboratory of Oral Pathology at the Federal University of Rio de Janeiro- Brazil from 2020 to 2023. Two oral pathologists reviewed conventional hematoxylin and eosin-stained slides of each case. Immunohistochemical stainings for CK19, Bcl-2, CD138, D2-40, EMA, and Ki-67 were performed in all cases. Case 1 was a 58-year-old man with a 2-year history of painless swelling of the right buccal mucosa, measuring approximately 5cm. Case 2 was of a 44-year-old man with a painful swelling in the left buccal mucosa lasting 3 years with drainage to the oral cavity. Case 3 was of a 74-year-old woman with a painful swelling in the left buccal mucosa of unknown duration. Microscopic evaluation of all 3 cases revealed a cyst lined with a few cell layers composed of columnar palisading basal cells and a corrugated parakeratin surface. The capsule comprised fibrous connective tissue with variable amounts of blood vessels with hemorrhage, nerve bundles, fat tissue, striated muscle fibers, and the absence of pilosebaceous units. No recurrence was observed after complete surgical removal. All epithelial layers of the 3 cases expressed positivity for CK19 and CD138, the basal cells were positive for Bcl-2 and D2-40, and the superficial epithelial layer was positive for EMA. All cases demonstrated a low proliferation index by Ki-67. This study represents a series of 3 cases of STK that affected the posterior buccal mucosa of middle-aged patients from Brazil, sharing histopathological and immunohistochemical features with odontogenic keratocyst.

Auricular epithelioid hemangioendothelioma: Two cases first diagnosed as auricular pseudocyst.

Epithelioid hemangioendothelioma (EHE) is a rare soft-tissue vascular neoplasm with a prevalence of one in one million. The present study firstly reports two cases of EHE occurring in the auricle. The clinical, histopathological and immunohistochemical features of two patients with auricular EHE are described, and the associated literature are reviewed. Two adult male patients each presented with an asymptomatic, unilateral soft skin-colored noninflammatory swelling of the auricle. Based on their clinical manifestations, both patients were initially diagnosed with auricular pseudocysts. Auricular excision surgery was performed under general anesthesia. The resected specimens were sent for pathological examination. Immunohistochemical examination showed that the specimens were positive for CD31, CD34, friend leukemia integration 1 (FLI-1), coagulation factor 8 and E26 transformation-specific-related gene, which was consistent with EHE. Follow-up after surgery showed no evidence of tumor recurrence. It may be concluded EHEs of low malignancy should be included in the differential diagnosis of patients with auricular pseudocysts. EHEs can be diagnosed based on their morphological and histological characteristics, with immunohistochemical positivity for FLI-1 and CD31 being suggestive of a diagnosis of EHE.

DICER1 Syndrome in a 25-Year-Old Female: Autopsy Case Report of Mixed Sex Cord-Stromal and Primitive Sarcoma Tumors with Diverse Differentiation Patterns

Abstract Introduction/Objective DICER-1 syndrome is a rare disorder characterized by germline mutations in the DICER1 gene, known to confer a lifetime risk of developing a variety of benign and malignant pathologies. This syndrome typically affects young individuals, though it exhibits exceedingly variable and relatively low penetrance of the neoplastic manifestations. Methods/Case Report We report on a 25-year-old woman with a history of metastatic DICER-1 related mixed pattern sex-cord stromal tumor of the ovary and primitive sarcoma of the liver. Her treatment involved extensive surgeries, including oophorectomy, salpingectomy, and partial hepatectomy, and multiple cycles of chemotherapy. Antemortem surgical pathological analyses revealed a poorly differentiated, primitive sarcoma in the liver and a sex cord-stromal tumor with Sertoli-Leydig and juvenile granulosa cell tumor-like features. The liver tumor exhibited a primitive spindle cell sarcoma with anaplastic features as well as chondrosarcomatous and rhabdomyosarcomatous patterns, suggesting a primary DICER1-related sarcoma. Immunohistochemistry confirmed the tumor’s complex multilineage differentiation, showing variable positivity for CD99, vimentin, CD10, BCL2, and Glypican-3. Positivity for Desmin and MyoD1 was focal, while the tumor was negative for inhibin, calretinin, AE1/3, AFP, and beta-catenin, overall supporting a DICER1-associated sarcoma diagnosis. She eventually died from terminal cardiac arrest secondary to complications from her metastatic cancer. An autopsy revealed a significant abdominopelvic mass leading to hemoperitoneum and extensive organ involvement, highlighting the aggressive nature of DICER1-associated malignancies. Results (if a Case Study enter NA) NA Conclusion This case underscores the importance of recognizing the broad manifestations of DICER-1 syndrome for accurate diagnosis, genetic counseling, and tailored management. Highlighting tumor morphology and immunohistochemical features enriches our understanding of DICER-1 pathology, advancing diagnosis and treatment prospects for affected individuals.

A Diagnostic Challenge in the Biopsy of a Mammographic Abnormality

Abstract Introduction/Objective Primary breast marginal zone lymphoma (MZL) is an uncommon subtype of extranodal lymphoma, and its diagnosis presents challenges, particularly in distinguishing it from lymphoplasmacytic lymphoma (LPL). MYD88 L265P mutation has been identified in a subset of marginal zone lymphomas, comprising 6-9% of cases. This genetic alteration further complicates the differentiation between MZL and LPL in breast tumors. We present a case highlighting the diagnostic complexities associated with primary breast MZL. Methods/Case Report A 71-year-old female patient underwent mammographic screening, which revealed a suspicious lesion in her left breast. Subsequent PET scan showed a hypermetabolic area consistent with a primary breast lesion. Biopsy histology exhibited a diffuse atypical lymphoid infiltration with varying proportions of neoplastic lymphocytes. Immunohistochemical analysis revealed positivity for CD20, PAX5, BCL2, CD138, MUM1, and negativity for CD3, CD5, Cyclin D1, CD10, CD23, CD34, BCL6, TDT, CD30, GATA3, and CK AE1/3. Additionally, there was lambda light chain restriction, and the Ki67 proliferation rate index was approximately 50%. Fish analysis indicated abnormal BCL6 gene rearrangement. Molecular genetic testing confirmed the presence of MYD88 mutation with c.794T>C p.L265P. Notably, bone marrow biopsy showed no abnormalities, with normal hematopoiesis. Serum electrophoresis and immunofixation detected an IgM monoclonal protein with lambda light chain specificity. Results (if a Case Study enter NA) NA Conclusion The diagnosis of primary breast MZL was favored over LPL due to the absence of common LPL- associated symptoms such as bone marrow involvement. However, the distinction between these entities remains challenging, underscoring the importance of comprehensive diagnostic approaches integrating histopathology, immunohistochemistry, and molecular genetics. Further research is warranted to enhance diagnostic certainty in such cases, particularly as the management of MZL and LPL becomes increasingly specific with the advent of novel therapeutic agents and ongoing clinical trials.

Isolated Perianal Langerhans Cell Histiocytosis in a Human Immunodeficiency Virus-Positive Adult: A Rare Incidental finding

Abstract Introduction/Objective Langerhans cell histiocytosis (LCH) is a rare disorder characterized by abnormal proliferation of antigen-presenting cells, primarily Langerhans cells. Although it commonly affects bones, skin, and lungs, involvement of the gastrointestinal tract is rare. Specifically, isolated perianal LCH is exceptionally uncommon, with only a few documented cases reported in the literature. Here, we report a case of incidental perianal LCH in an adult HIV patient, highlighting the exceptional rarity and clinical importance of this occurrence. Methods/Case Report A 56-year-old Caucasian male with HIV underwent surgical resection of a 0.5 x 0.4 x 0.3 cm verrucous lesion on the posterior anal margin. His past medical history included granulomatous lymphadenitis, penile warts, and anal dysplasia. Microscopic examination of the excised tissue revealed Langerhans cells with characteristic features, including abundant eosinophilic cytoplasm and irregular nuclear membranes (resembling “coffee-bean” or “folded paper” appearance). Immunohistochemical analysis confirmed the diagnosis by demonstrating positivity for CD1a, S100, and CD68. The BRAF mutation was evaluated on the same paraffin-embedded block, which revealed the lack of the mutant BRAF V600E. PET-CT imaging showed no evidence of metastatic disease, emphasizing the isolated nature of the perianal LCH in this patient. Results (if a Case Study enter NA) NA Conclusion This case highlights the significance of recognizing and thoroughly evaluating rare and incidental conditions such as LCH in HIV patients. Our findings emphasize the importance of maintaining a high index of suspicion for LCH among healthcare providers and ensuring proper follow-up to rule out systemic involvement. Furthermore, there is a need for future studies to investigate the correlation between LCH and HIV. Given its rarity and diverse clinical presentation in immunocompromised individuals, a multidisciplinary approach, tailored treatment plans, and long-term surveillance with imaging modalities like PET/CT are essential for effectively managing adult-onset isolated LCH.

Intravascular Nodular Fasciitis Mimicking Thrombotic Complications in a 16-year-old male with May-Thurner Syndrome

Abstract Introduction/Objective Nodular fasciitis is a rare benign myofibroblastic proliferation commonly mistaken for malignant tumors due to its rapid growth and clinical presentation. May-Thurner Syndrome (MTS), characterized by compression of the left common iliac vein by the right common iliac artery, predisposes individuals to deep vein thrombosis (DVT). However, here we present a unique case of intravascular nodular fasciitis presenting as thrombotic complications in the context of MTS in a 16-year-old male. Methods/Case Report A 16-year-old male presented with progressive left hip and leg pain accompanied by recent swelling. Ultrasound revealed occlusive thrombi within the left side external iliac, common superficial femoral, and great saphenous veins, along with nonocclusive thrombi in left deep femoral vein. Magnetic resonance venography confirmed MTS and extensive thrombosis. Thrombectomy was done with fragments sent to pathology. Microscopic examination showed cellular areas with loose myxoid composition, proliferating spindle, myofibroblastic/fibroblastic, and stellate cells arranged in irregular bundles. Additional microscopic findings included mild cellular atypia, mitoses, focal macrophage aggregates, occasional multinucleate forms, foci of hemorrhage, fibrin exudate, ingrowing fibroblasts, and increased vascularization. Immunohistochemical stains demonstrated positivity for SMA, CD31, ERG, and CD34, highlighting prominent vascularization, while desmin, myogenin, myoglobin, STAT6, beta-catenin, S100, and AE1/AE3 were negative. Differential diagnosis included intravascular fasciitis, and possibly organizing thrombus with myxoid stroma. USP6 gene rearrangement (FISH) study was positive, confirming the diagnosis of nodular fasciitis. Results (if a Case Study enter NA) N/A Conclusion This case emphasizes the significance of maintaining a broad differential diagnosis when assessing specimens sent as thrombectomies. Recognizing intravascular nodular fasciitis as a potential presentation mimicking thrombosis is essential for accurate diagnosis and management.

Solid-basaloid Variant of Mammary Adenoid Cystic Carcinoma – Report of an Unusual Case with Literature Review

Abstract Introduction/Objective Adenoid cystic carcinoma (AdCC) of breast is a rare subtype of malignancy, constituting approximately 0.1% of all breast carcinomas. The solid-basaloid variant (SB-AdCC) is exceedingly uncommon. Here, we present such an unusual case of SB-AdCC. Methods/Case Report A 64-year-old woman who underwent screening mammography presented with abnormal findings, revealing a hypoechoic ovoid, lobulated nodule at 7:00 of the left breast, which prompted an ultrasound- guided biopsy. Histologically, the biopsy cores demonstrated a 9 mm infiltrative round, solid nests with focal “cribriforming” areas. It was composed of monomorphic basaloid epithelial cells with marked nuclear atypia and high mitotic count. High-grade ductal carcinoma in situ, solid papillary carcinoma, and nonspecific invasive carcinoma were in differentials. Immunohistochemical (IHC) staining expressed positivity for CD117 and CK 5/6, while p63, SMMHC, and synaptophysin were negative. MYB gene rearrangement confirmed by fluorescence in situ hybridization. As expected, the tumor lacked ER, PR, and HER2 expression by IHC. Left breast mastectomy and axillary lymph node dissection have been scheduled. Results (if a Case Study enter NA) NA Conclusion Per literature review, the mean age of SB-AdCC at diagnosis was 68 years (33-84 years) with an average tumor size of 25 mm (12-70 mm). It had more aggressive behavior, with a higher propensity for lymph node metastasis, locally recurrence, and distant metastasis. The median disease-free survival was 46.5 months versus 151.8 months in those with class AdCC. Notably, neovascularization has emerged as a strong independent predictor of outcome in SB-AdCC. Most patients were treated with surgical excision, axillary lymph node dissection, and/or adjuvant chemotherapy. Limited studies demonstrated that neoadjuvant chemotherapy may induce an excellent response. Furthermore, a distinct molecular mutation enriched in NOTCH and CREBBP genes has been identified, which could be novel potential therapeutic target. Thus, awareness of this extremely rare breast cancer subtype and accurate differentiation from other entities are paramount for appropriate management strategies.

Primary Mast Cell Sarcoma of the Maxillary Sinus and Gingiva Mimicking Malignant Neuroendocrine Tumor: A Case Report

Mast cell sarcoma (MCS) is an extremely rare and aggressive malignancy primarily affecting bones, with limited literature associating it with neuroendocrine marker expression. This report presents a rare case of MCS arising in the maxillary sinus and gingiva. A 74-year-old man presented with a progressively enlarging ulcer on the right-sided upper gingiva. Magnetic resonance imaging revealed a 3.4 cm tumor on the floor of the right maxillary sinus. The patient underwent an inferior maxillectomy and right-sided neck dissection. Microscopically, the tumor consisted of monotonous round cells with oval nuclei, vesicular chromatin, inconspicuous nucleoli, and brisk mitoses. A panel of immunohistochemical stains was initially applied to exclude common sinonasal undifferentiated neoplasms, such as sinonasal undifferentiated carcinoma, melanoma, rhabdomyosarcoma, Ewing sarcoma, and lymphoma. The tumor cells showed patchy staining for INSM1 and synaptophysin, but were negative for AE1/AE3, CAM5.2, p40, chromogranin, S100, HMB45, NKX2.2, desmin, CD45 (LCA), CD3, and CD20, with intact INI1 and BRG1 expression. No specific diagnosis could be rendered based on the staining results, leading to consideration of other rare malignancies. Additional staining revealed positivity for CD117, mast cell tryptase, CD13, CD33, CD43, and CD68, confirming the MCS diagnosis. Molecular testing for KIT mutation was negative. Subsequent bone marrow biopsy demonstrated infiltration of atypical mast cells, which led to a diagnosis of mast cell leukemia. Despite high-dose chemotherapy, the patient died three months after the initial diagnosis. The undifferentiated epithelioid morphology and unusual aberrant neuroendocrine marker expression posed significant diagnostic challenges. The major differential diagnoses were discussed in this report.

Rare Presentation of Extraskeletal Osteosarcoma Mimicking Phyllodes Tumor

Abstract Introduction/Objective A 57-year-old female presented with a palpable mass in the left breast, measuring up to 9 cm by ultrasound. core needle biopsy identified an atypical spindle cell lesion. The differential diagnosis included a metaplastic carcinoma, borderline phyllodes tumor, malignant phyllodes tumor with potential sarcomatous transformation. Methods/Case Report Histological examination of the tumor was performed, and immunohistochemical stains were conducted to characterize the lesion. Further consultation with a specialized pathologist at the University of Michigan was sought to confirm the diagnosis. Molecular analysis was performed to assess for specific genetic alterations and expression patterns. The histological examination revealed a proliferation of atypical spindle cells forming a fascicular and storiform pattern, with numerous large, pleomorphic, multinucleated tumor cells and a high mitotic rate. Immunohistochemical stains showed strong positivity for CD10 and vimentin, with focal weak expression for desmin, and negativity for a broad panel of cytokeratins and other markers. Consultation with Dr. Abbott at the University of Michigan supported the diagnosis of extraskeletal osteosarcoma. Molecular analysis revealed PD-L1 expression and absence of NTRK gene fusions. FISH analysis showed suggestive alterations including loss of BRAF gene, loss of MYC, and suggestive gains or polysomy of PTEN gene. Results (if a Case Study enter NA) NA Conclusion The case represents a rare presentation of extraskeletal osteosarcoma in the breast, with distinctive histological and immunohistochemical features. The comprehensive workup including histology, immunohistochemistry, and molecular analysis aids in accurate diagnosis and potential therapeutic implications. Further research may elucidate the underlying mechanisms and treatment options for this uncommon malignancy.

Malakoplakia, a rare inflammatory condition presenting as a colon polyp

Abstract Introduction/Objective Malakoplakia is a rare histiocytic disease caused by defects in phagocytic or degradative functions of histiocytes in response to gram negative coliforms (E. coli or Proteus) that results in chronic inflammatory state, followed by intracellular deposition of iron and calcium (known as Michaelis-Gutmann bodies). It’s more common in immunocompromised patients and the mean age at diagnosis is fifth decade. It occurs in all organs, common in GU tract, particularly bladder, but also seen in gastrointestinal tract (most commonly colon, followed by stomach and duodenum), central nervous system and female genital tract. In gastrointestinal tract, it can present as a polyp with diffuse mucosal involvement, submucosal thickening, and even may cause mass. Methods/Case Report A 60 -year-old male smoker presented to our hospital with history of colon polyps; colonoscopy revealed a 6 mm sessile polyp at the hepatic flexure. A biopsy was performed which showed numerous epithelioid histiocytes with granular eosinophilic cytoplasm, abundant Michaelis-Gutmann bodies and increased lymphocytes. Immunohistochemical stains showed diffuse positivity for CD68; and PAS stain was positive for histiocytic cytoplasmic granules. Based on this data, the diagnosis of Malakoplakia was confirmed. Malakoplakia is treated with antibiotics that concentrate in macrophages (quinolones or trimethoprim-sulfamethoxazole), antibiotics directed against E. coli, surgery and possibly discontinuation of immunosuppressive drug therapy. Results (if a Case Study enter NA) Malakoplakia, in this case, was presented clinically as a sessile colon polyp and histologically showed numerous epithelioid histiocytes with granular eosinophilic cytoplasm, with Immunohistochemical stains (CD68; and PAS stain) the correct diagnosis was made. Other presentations of Malakoplakia include diffuse mucosal involvement, submucosal thickening, or mass. Histologically, it may rarely be mistaken as signet ring carcinoma. These variable presentations in GU tract or colon can be interpreted as malignancy with consequent unnecessary interventions. Hence, awareness of Malakoplakia with careful histopathologic examination and the use of immunohistochemical studies are advisable in that cases. Conclusion We would like to emphasize that Malakoplakia can be clinically and histologically misdiagnosed as a malignant condition; therefore histopathologic and immunohistochemical studies are needed to correctly diagnose this entity.

SMARCA4-Deficient Undifferentiated Carcinoma of the Gastroesophageal Junction: A Case Report

Abstract Introduction/Objective To report a rare case of the newly characterized variant of gastric carcinoma; undifferentiated carcinoma with intact SMARCB1 (INI1) but lost SMARCA4/SMARCA2, and approach to diagnosis. Methods/Case Report A case of gastric mass extending to the gastroesophageal junction, microscopically, showing sheets of atypical, medium to large, discohesive, polygonal cells with large eccentric and pleomorphic nuclei, variably prominent nucleoli, and eosinophilic cytoplasm with brisk mitosis, in the background of marked necrosis and granulomatous inflammation. And having focally positive staining for cytokeratin and negative for melanoma, diffuse large B-cell lymphoma, high grade neuroendocrine tumor, sarcoma, rhabdoid/myoid-specific immunohistochemistry (IHC) markers. The case was further characterized with immunophenotypic, cytogenetic, and molecular findings. Results (if a Case Study enter NA) By immunohistochemistry (IHC), the large tumor cells were positive for vimentin, FLi-1 and patchy CD71. A subset of tumor cells showed CD34 positivity. The tumor cells were mainly negative (with rare focal positivity) for all cytokeratin including (CK AE1/AE3, EMA, and CK OSCAR). Tumor cells were negative for specific markers for melanoma, GIST, sarcomatous tumors, squamous cell carcinoma, hematolymphoid malignancies, and neuroendocrine tumors. EBER-ISH and HHV-8 were negative. The Ki67 showed a proliferative index of ~60%. The tumor cells demonstrated retention of INI1 (SMARCB1) with loss of both SMARCA2 and SMARCA4 by IHC. Molecular studies detected an inactivating mutation of the retinoblastoma-1 gene (RB1 I124Rfs*6) and TP53 with altered function compared to wild-type (TP53-G245S) with no mutations or deletion of SMARCB1 gene. The status of SMARCA4 gene came as indeterminate. No microsatellite Instability detected. Conclusion Our study demonstrates the challenge of diagnosing the SMARCA4/SMARCA1-deficient undifferentiating gastric carcinoma especially with negative cytokeratin stains, showing the immunohistochemistry profile of the tumor and its molecular findings in our case.

Immunoexpression of CD34, CD68 and CD3 in Cadmium-Induced Liver Damage and Protective Effectiveness of Bee Bread (Perga)

Cadmium (Cd) is one of the potent environmental toxicants that causes oxidative stress in many organs of the body, including the liver. Perga (bee bread) is used for apitherapeutic purposes due to its medicinal properties. This study was conducted to investigate the effectiveness of perga on endothelial damage and inflammatory cell activation in the liver as a result of exposure to Cd. For this purpose, 32 male Wistar rats (8 rats/group) were randomly divided into 4 groups, as the control, perga (0.5 g/kg of perga), Cd (5 mg/kg of CdCl2), and Cd + perga (0.5 g/kg of perga + 5 mg/kg of CdCl2) groups. Daily intragastric Cd and/or perga was administered for 4 weeks. At the end of the study, the rats were euthanized and liver tissue sections were taken and stained with hematoxylin-eosin and Masson’s Trichrome. Immunohistochemically, the reactivity of the liver sinusoidal endothelium was determined using CD34, the reactivity of the Kupffer cells was determined using CD68, and the levels of T-lymphocyte cells were determined using CD3 antibodies. Exposure to Cd caused significant histological changes in the liver. Immunohistochemically, exposure to Cd caused an increase in the expressions of CD34, CD68, and CD3. On the other hand, the cotreatment of Cd and perga caused partial improvement in some histopathological changes. Compared to the Cd group, there was a decrease in CD34 and CD68 positivity in the Cd + perga group, while no significant difference was detected in the number of CD3-positive cells between the groups. The results revealed that the histopathological changes and inflammation in the rat liver could partially improve with perga supplementation.

A COMPARATIVE STUDY OF CLINICOHISTOPATHOLOGICAL CORRELATION IN PATIENTS OF PSORIASIS AND PSORIASIFORM LESIONS WITH KI67 AND CD34 IMMUNOHISTOCHEMICAL EXPRESSION

Objectives: Psoriasis, characterized by chronic inflammation of the skin, stands as a notable example of a psoriasiform tissue pattern. In dermatology, the term “psoriasiform dermatitis” frequently appears across various inflammatory skin conditions, presenting challenges for dermatologists and pathologists alike in accurate differentiation. Relying solely on clinical features may prove insufficient in distinguishing between psoriasis and other psoriasiform dermatoses. Therefore, comprehensive differentiation requires consideration of clinical, histopathological, and immunohistochemical factors. Our study is to compare the clinicohistopathological features of psoriasis and psoriasiform dermatitis and to evaluate the immunohistochemical expression of CD34 and Ki67 in psoriasis and psoriasiform dermatitis. Methods: This retrospective study was conducted at the Department of Pathology, Mediciti Institute of Medical Sciences, Ghanpur, focusing on cases between January 1, 2020, and December 31, 2022. Clinical histories were extracted from requisition forms submitted by the Department of Dermatology. The study analyzed paraffin blocks from 50 patients each diagnosed with psoriasis and psoriasiform dermatitis. Formalin-fixed paraffin-embedded tissue samples were processed into 4-micron sections and initially stained with hematoxylin and eosin. The immunohistochemical analysis included primary antibodies against Ki-67 and CD34, with positive controls sourced from strongly positive samples of squamous cell carcinoma and capillary hemangioma, respectively. Appropriate negative controls were employed to ensure the accuracy of our findings. Results: In our study, we analyzed a total of 100 cases, comprising 50 cases each of psoriasis and psoriasiform dermatitis. Among the psoriasis cases, there was a male predominance with 29 males and 21 females, while psoriasiform dermatitis also showed male predominance with 32 males. The mean age was 33.8 years for psoriasis and 34.8 years for psoriasiform dermatitis. The majority of psoriasis cases fell in the 21–30 years age range, whereas for psoriasiform dermatitis, it was between 31 and 40 years. Significantly, our immunohistochemical analysis revealed that the mean staining intensity of the two markers was notably higher in psoriasis compared to psoriasiform dermatitis. Conclusions: In our study, we observed that the expression levels of Ki-67 and CD34 biomarkers were significantly elevated in psoriasis compared to psoriasiform dermatitis. Notably, four cases of psoriasiform dermatitis demonstrated positivity for CD34 in our analysis. This finding suggests a potential avenue for further research to explore the implications of CD34 positivity in psoriasis.

Low Grade Extrauterine Endometrial Stromal Sarcoma Arising from Peritoneum Endometriosis: A Case Report and Literature Review

Introduction: Endometrial stromal sarcoma (ESS) is an uncommon condition that accounts for approximately 0.2% of all reproductive tract malignancies. Among the various subtypes of ESS, low-grade extrauterine endometrial stromal sarcoma (LG-EESS) is even rarer and has only been reported in a limited number of case studies. Case Presentation: We reported a case of LG-EESS in a 35-year-old woman with a five-year history of stage IV endometriosis. The patient presented with chronic abdominopelvic pain and dysmenorrhea. Transvaginal ultrasound showed bilateral tubo-ovarian complexes with multicystic structures, while MRI revealed solid lesions with T1 iso signal, T2 hypersignal, and diffusion restriction, indicating metastatic implantation extending to the peritoneum and subhepatic region. A core needle biopsy confirmed LG-EESS, and immunohistochemistry showed CD10 positivity, aiding in the diagnosis and distinguishing it from other tumors. Conclusions: Our case highlights the potential utility of preoperative diagnostic imaging, particularly MRI, in the evaluation of LG-EESS. Additionally, it emphasizes the importance of considering the possibility of extrauterine ESS, as this tumor exhibits histopathological features and clinical behavior similar to its uterine counterpart.