Diffuse CD34 Research Articles

Clinical relevance of subtyping CTNNB1‐mutated hepatocellular adenomas: Different risk patterns according to the mutation type

AbstractBackground and AimsBeta‐catenin‐activated hepatocellular adenomas (b‐HCA) with exon 3 (ex3) non‐S45, ex3 S45 or ex7/8 mutations display different glutamine synthetase (GS)‐immunostaining patterns; the latter two show a GS‐positive/CD34‐negative rim contrasting with diffuse CD34 in the HCA core. Our objective was to determine whether discriminating the three b‐HCA mutation subtypes is clinically relevant.MethodsWe analysed the clinicopathological data of the three b‐HCA subtypes (37 resected cases) and compared it with the corresponding subtypes of beta‐catenin‐activated inflammatory HCA (b‐IHCA, 40 cases).ResultsThe mean age of b‐HCA ex7/8 and ex3 S45 were 25.9 and 27.3 years respectively. Clinical bleeding occurred in 67% and 63%, including five cases of pregnant women; malignant transformation was not observed in these two subtypes. The mean age of the b‐HCA ex3 non‐S45 subtype (41 years) was significantly higher; clinical bleeding occurred in 14% while all cases contained malignancy. Such differences in age and clinical complications were not found in the b‐IHCA subtypes. Additionally, we found abnormal vessels in b‐HCA ex3 S45 and ex7/8, near the GS+/CD34− rim, which was not seen in ex3 non‐S45. These vessels can function as an adjunct to discriminate between the b‐HCA subgroups.ConclusionIn our series, b‐HCA ex7/8 and ex3 S45 patients are significantly younger and have higher clinical bleeding risk than b‐HCA ex3 non‐S45 patients who have a higher malignant risk. Hence, in b‐HCA, due to the differences in clinical complications, it is clinically relevant to identify all three subtypes individually.

Intra-Abdominal Epithelioid Neoplasm With EWSR1::CREB Fusions Involving the Kidney: A Clinicopathologic and Molecular Characterization With an Emphasis on Differential Diagnosis

Soft tissue neoplasms, harboring fusions between EWSR1 and FUS with genes encoding CREB transcription factors family (ATF1, CREB1, and CREM), are an emerging heterogeneous group of mesenchymal tumors that differ significantly in morphology, immunophenotypes, and behavior. Recently, EWSR1/FUS::CREB fusions have been recognized to define a group of aggressive neoplasms of epithelioid morphology with multiple growth patterns and a striking predilection for mesothelial-lined cavities. These neoplasms presenting as a primary neoplasm of intra-abdominal visceral organs are rare, which could elicit a wide range of differential diagnoses because of their diverse morphologies and immunohistochemical profiles. We report 3 cases of intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions involving the kidney. This study included 2 female patients and 1 male patient, with age at presentation ranging from 17 to 61 years (mean: 32 years). All the patients underwent radical nephrectomy without adjunctive therapies. Grossly, the tumors were large, and all were solitary masses with sizes ranging from 5.6 to 30.0 cm (mean: 14.5 cm). Histologically, the neoplasms showed infiltrating and indistinct borders and were composed predominantly of monomorphic round-to-epithelioid cells with variable amounts of pale-to-clear cytoplasm, arranged in cords, nests, and sheets and embedded in a sclerotic hyalinized stroma with variable lymphoid cuffing either intermixed or at the periphery. Notably, a hemangiopericytomatous growth pattern was commonly seen. Nuclear atypia was mild, and mitotic activity was scarce. Immunohistochemically, all 3 cases were at least focally positive for epithelial membrane antigen and keratin AE1/AE3, with 2 tumors showing focal MUC4 expression and 1 case displaying diffuse CD34 and focal CAIX positivity. Targeted RNA sequencing identified EWSR1::CREM fusion in 2 cases and EWSR1::ATF1 fusion in 1 case. Subsequent fluorescence in situ hybridization analysis confirmed the RNA sequencing results. On follow-up, 1 patient developed multiple spinal bone metastases 5 months after the surgery while the other 2 patients were free of disease 9 and 120 months after diagnosis, respectively. Our findings demonstrate that intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions may rarely occur primarily in the kidney and should be included in the differential diagnosis of primary renal epithelioid mesenchymal neoplasms.

Ultrastructural differences between synovial sarcoma and solitary fibrous tumor: comparative study in adult patients from the National Cancer Institute of Mexico

ABSTRACT Synovial sarcoma (SS) and solitary fibrous tumor (SFT) are entities with considerable morphological and immunohistochemical similarities that sometimes show a non-confirmatory profile (TLE1 negative, CD34 and focal or negative STAT6 and lack of specific fusion IHC markers), in which the utility ultrastructure is unknown. A cross-sectional, retrospective, analytical, nonexperimental study was carried out by the Department of Pathology of the National Cancer Institute of Mexico (INCan) e from January 1, 2009 to December 31, 2018. With 17 SFT cases with diffuse or focal CD34 and STAT6 positivity and 18 cases of SS with positive FISH molecular test t(X:18) breakapart were studied by electron microscopy of fresh glutaraldehyde fixed or paraffin-embedded tissue. The ultrastructural findings with a significant difference present in the SS were tandem tight junctions, desmosomes and abundance of dilated rough endoplasmic reticulum (RER) cisternae (p < 0.001, 0.003, and 0.001, respectively); while in the (SFT) the presence of abundant glycogen, basal lamina, long and slender cytoplasmic processes, pinocytic vesicles, hemidesmosomes, and/or dense plaques, collagen skein, and microvilli-like buds (p = 0.028, 0.005, and <0.001 for the last five). We then infer that the five distinctive markers of the SFT are the collagen skeins intermingled with cellular processes in a shape of “squid can,” and the pinocytic vesicles as they were not observed in any case of SS. Conversely, tandem junctions were not found in any SFT case. Although the presence of multivesicular buds in the SFT was not significant, it had not been previously described.

Dermatofibrosarcoma protuberans: Under the mask of scar

Dermatofibrosarcoma protuberans (Darier–Ferrand) is a rare mesenchymal tumor of fibrohistiocytic genesis with moderate malignancy and low incidence of metastasis, the pathogenesis and etiology of which remain unclear. The diagnosis is based on the clinical picture of a reddish-brown dense plaque or papule that gradually becomes a painful node with ulceration. Histological examination reveals the infiltrate with a moire pattern in the dermis in the form of fusiform cells with diffuse CD34+ staining during immunohistochemical analysis. Treatment of dermatofibrosarcoma protuberans (Darier–Ferrand) is a serious problem due to the high tendency for recurrence after removal. The methods described in the literature include extensive excision, Mohs surgery, chemotherapy, radiation therapy and targeted treatment with an anticancer protein-tyrosine kinase inhibitor.&#x0D; The authors present their own clinical observation of a patient with dermatofibrosarcoma protuberans (Darier–Ferrand) in whom a diagnostic error by only visual method and an incorrect treatment led to the worsening of skin process. The interest of this clinical observation lies in the difficulty of diagnosis during the initial visit, in the complexity of differential and morphological diagnosis.

Challenges in Diagnosis of Steatohepatitic Hepatocellular Carcinoma on a Biopsy Specimen

Abstract Introduction/Objective Hepatocellular carcinoma (HCC) is the most common primary liver tumor. Steatohepatitic hepatocellular carcinoma (SH-HCC) is a subtype that is associated with metabolic syndrome and alcoholic hepatitis. Diagnosing SH-HCC can be extremely challenging on a biopsy specimen, given that steatohepatitis-like changes can be seen in focal nodular hyperplasia and hepatic adenoma. Herein, we present a very challenging case of SH-HCC that was initially diagnosed as a well-differentiated lesion after multi-institutional consultations. Methods/Case Report A 54-year-old female with past medical history of diabetes and hypertension presented with flank pain and a 2.7 cm liver mass in a background of diffuse hepatic steatosis by CT scan, concerning for malignancy. Viral hepatitis serology workup was negative. Results (if a Case Study enter NA) The liver core biopsy reveals a well-differentiated hepatic lesion with areas of steatosis, fibrosis, and features of steatohepatitic changes including ballooning hepatocytes and Mallory-Denk bodies. No significant cytological atypia is identified. No definitive loss of reticulin is seen by reticulin stain. The cytological or architectural atypia was insufficient in isolation to diagnose HCC. The lesion cells are positive for HepPar-1 and Arginase-1, while negative for Glypican. Diffuse sinusoidal CD34 staining is present. Ki-67 proliferative index is approximately 2%. These changes did not permit a confident diagnosis of hepatic adenoma or hepatocellular carcinoma. The case was sent for consultation by multiple institutions with a consensus diagnosis of well-differentiated hepatic lesion/neoplasm. A follow-up liver wedge resection shows a hepatic neoplasm with areas of loss of reticulin staining. Focal stromal invasion is present. The neoplastic cells are positive for HepPar-1, Arginase-1, glutamine synthetase and Glypican (patchy). Final diagnose was rendered as SH-HCC. Conclusion The diagnosis of SH-HCC requires high level of suspicion on a biopsy specimen, especially in a background of steatohepatitis. A reticulin stain and immunohistochemical stains may not be helpful. Clinical- radiological correlation should always be considered.

Extranodal NK/T-Cell Lymphoma Predominantly Composed of Anaplastic Cells: A Frequently Misdiagnosed and Highly Aggressive Variant.

Extranodal NK/T-cell lymphoma (ENKTL) is a non-Hodgkin lymphoma associated with the Epstein-Barr virus that primarily affects individuals in East Asia and indigenous populations in Central and South America. Morphologically, ENKTL typically consists of medium-sized cells or a combination of small and large cells. This report presents 10 cases characterized by predominantly anaplastic cells with diffuse expression of CD30, resembling anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALK-negative ALCL) and demonstrating highly aggressive behavior. The cohort included 9 males and 1 female, ranging in age from 29 to 65 years (median age: 47y). Eight patients presented with nasal disease, while 2 had non-nasal disease. Five patients had stage I/II disease, and the remaining 5 had stage III/IV disease. Morphologically, necrosis was observed in 9 cases, angiocentric-angiodestructive growth in 3 cases, and pseudoepitheliomatous hyperplasia in 2 cases. Anaplastic cells predominated in all cases, with some displaying eccentric, horseshoe-shaped, or kidney-shaped nuclei (referred to as "Hallmark" cells). The morphology profile was monomorphic in 3 cases and polymorphic in 7 cases. Immunohistochemically, all cases tested positive for cytotoxic granule markers (TIA1 and granzymeB) and Epstein-Barr virus-encoded RNA. Cytoplasmic expression of CD3ε and CD56 was observed in 9 of 10 cases. Interestingly, most cases (7 of 8) exhibited variable expression of MuM1, ranging from 10% to 90%. All cases showed diffuse positivity for CD30 but were negative for ALK, resulting in 3 cases being initially misdiagnosed as ALK-negative ALCL. Compared with nonanaplastic cases, anaplastic cells predominant ENKTL had a significantly higher frequency of "B" symptoms, bone marrow involvement, hemophagocytic lymphohistiocytosis, and higher Ki67 proliferative index. These findings provide valuable information for pathologists, expanding their understanding of the cytologic spectrum of ENKTL. This rare variant of ENKTL, characterized by the predominance of anaplastic cells and diffuse CD30 expression, exhibits high aggressiveness and should be differentiated from ALK-negative ALCL. Awareness of this uncommon variant is crucial in preventing misdiagnosis and ensuring the timely initiation of therapy.

P20.02.B ELECTRO-CLINICAL, NEUROIMAGING FEATURES AND NEUROPATHOLOGICAL CHARACTERIZATION OF POLYMORPHOUS LOW-GRADE NEUROEPITHELIAL TUMOR OF THE YOUNG (PLNTY)

Abstract BACKGROUND Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) has been recently recognized by 2021 WHO Central nervous system classification. It is an epileptogenic tumor type, affecting mostly children and young adults, with peculiar radiological, and pathomolecular features. PLNTY is a very rare tumor, described in only 52 cases up to now. Herein, we describe 13 patients with electro-clinical and neuroimaging findings, associated to histopathological and molecular findings. MATERIAL AND METHODS We selected PLNTY patients from our Cancer Registry (Apr 2017-Dec 2022), and collected electro-clinical, radiological and histo-molecular data. Minimum follow-up was 6 months. Exams included EEG, long-term scalp video-EEG, pre-surgical brain computer tomography and Magnetic Brain Imaging (MRI). Immunohistochemistry included CD34, IDH1-R132H, GFAP, synaptophysin, ATRX, p53 and FGFR3. IDH1-2, BRAF (V600E) sequencing, Kiaa1549:BRAF, FGFR3:TACC3, FGFR2:kii1598 and FGFR2:CTNNA3 fusion analyses will be performed. RESULTS We describe 13 patients, median age 20.6 years (range 12.3-46.4). Most patients showed memory/executive impairment and had epilepsy, with an onset from 5 months-21 years before surgery. The main feature of seizures was a difficult localization and even lateralization, both semiologically and electrographically. Post-surgical seizure control was excellent.The tumors (n=11/13 temporal) presented as solid or solid-cystic cortical mass with no mass effect and unclear hedges. Calcifications were present in 4, and cysts in 6 cases. Microscopically the tumors showed infiltrative growth pattern, oligodendroglial-like cells, strong and often diffuse CD34 immunostaining, and frequent intra-tumoral calcifications. Malformation of cortical development, namely FCD type IIIB, was associated to PLNTY in 2 cases. Proliferation activity (MIB-1 LI) was very low (1%) in all cases except one (MIB-1 LI which reached 3%). CONCLUSION This study significantly extends the number of reported PLNTY associated to epilepsy, mostly characterized by bilateral interictal epileptiform discharges and difficult to lateralize seizures.The MRI features were heterogeneous and the differential diagnosis should include also dysplasia and glioneuronal tumors. PLNTY, despite its name, occurs also in adults, and electro-clinical and radiological diagnosis can be challenging. As recently described, PLNTY can show the MAPK pathway activating alterations, that are under investigation in our cohort to eventually clarify their role in the evolution of the disease. SUPPORT the study is partially supported by the Health Italian Minister (RC).

An unusual diffuse CD34 staining in an olfactory groove cellular schwannoma: Case report

Background: Intracranial schwannomas are benign lesions, expected to exhibit characteristic ultrastructural features and immunophenotypic profile, typically being S-100, SOX10 and collagen-IV positive, while other markers, including CD34, are not usually expressed and are employed in the diagnostic elimination process. Case presentation: A 51-year-old female presented with a rapidly deteriorating neurological status. MRI showed a heterogeneous enhancing neoplasm of the anterior fossa. Preoperative differential diagnosis predilected an esthesioneuroblastoma. A bifrontal craniotomy with total excision of the lesion was performed. Dural infiltration was present. There was no association with the olfactory system. Microscopic examination revealed a uniform population of spindled to slightly epithelioid cellular proliferation with no significant atypia, low mitotic activity, and foci of necrosis. Upon immunohistochemical investigation the tumor was consistent with cellular schwannoma. Diffuse positivity for CD34 was an unusual finding. Discussion: Cellular schwannoma should be considered in the presence of an anterior fossa tumefaction. Olfactory nerve is not directly associated with these lesions. Various theories have been proposed, with the meningeal trigeminal branches’ origin being the most probable. The characteristic ultrastructural Antoni formations may be scarce or even absent in cellular schwannomas creating potential diagnostic difficulties. Unusual diffuse CD34 positivity should not be employed for excluding the diagnosis.

CD30 expression in cutaneous B-cell lymphomas.

CD30 expression has been infrequently described in cutaneous B-cell lymphomas (CBCLs). We examined CD30 expression in reactive lymphoid hyperplasia (RLH) and CBCL and correlated expression with clinicopathologic features. CD30 was examined in 82 CBCL patients and 10 RLH patients that had been evaluated in our cutaneous lymphoma clinics. The CBCL patients included: primary cutaneous follicle center lymphoma (PCFCL), Grade 1/2 systemic/nodal follicular lymphoma (SFL); primary cutaneous marginal zone lymphoma/lymphoproliferative disorder (PCMZL/LPD); systemic marginal zone lymphoma (SMZL); primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT); and extracutaneous/systemic diffuse large B-cell lymphoma (eDLBCL). We scored CD30 expression for intensity and extent and related CD30 expression to age at first diagnosis, sex, site of biopsy, clinical appearance, extracutaneous involvement, multiple cutaneous lesions, B-symptoms, lymphadenopathy, positive positron emission tomography/computed tomography (PET/CT), elevated lactate dehydrogenase (LDH), and positive bone marrow biopsy. CD30 expression was identified in 35% of CBCL, ranging from few, weak, scattered cells to strong and diffuse expression. It was most common in PCFCL and was not expressed in PCDLBCL-LT. Rare PCFCL expressed strong, diffuse CD30. Some cases of PCMZL/LPD, SMZL, FL, and RLH showed scattered, strongly positive cells. CD30 expression in CBCL was associated with favorable clinical features: younger age, negative PET/CT, and an LDH within normal limits. CD30 may be expressed in CBCL, possibly causing diagnostic confusion. CD30 expression was most commonly identified in PCFCL and is associated with favorable clinical features. In cases with strong and diffuse expression, CD30 could be a therapeutic target.

Unusual presentation of Giant Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is an uncommon, soft tissue sarcoma with a low metastatic potential but high rate of recurrence after surgical intervention. This tumor is characterized by a long history of slow growth. DFSP usually occurs on trunk and proximal extremities but rarely touches distal extremities such as hands, fingers, or foot below knees. We present a case of giant DFSP of the distal extremity, with a post-traumatic onset in childhood and a very long course. A 45-year-old patient presented with a tumoral lesion of the foot, evolving since 35 years with an onset at the age of 10 years, after a strong trauma of the 3rd toe. Physical examination revealed a reddish purple polynodular neoplastic lesion with a firm consistency. One of these nodular masses was ulcerated with areas of necrosis. The CT scan did not detect any bone involvement. Magnetic resonance imaging revealed a heterogeneously enhancing mass lesion on the dorsal aspect of the left forefoot. In depth, this mass invaded the dorsal interosseous muscles. The histopathological study was in favor of DFSP, with evidence of spindle-shaped tumor cells arranged in a storiform pattern. On immunohistochemistry (IHC), the cells expressed intense and diffuse CD34 and were negative for Desmin and S-100. The localization or occurrence of DFSP after a long period of trauma should not mislead the diagnosis. A careful histological study with IHC should be carried out in order to set up an appropriate treatment.

Cryptic COL1A1-PDGFB fusion in dermatofibrosarcoma protuberans: a clinicopathological and genetic analysis

Objective: To investigate the clinicopathological and cytogenetic features of cryptic COL1A1-PDGFB fusion dermatofibrosarcoma protuberans (CC-DFSP). Methods: Three cases of CC-DFSP diagnosed in West China Hospital, Sichuan University, Chengdu, China from January 2021 to September 2021 were studied. Immunohistochemistry for CD34 and other markers, fluorescence in situ hybridization (FISH) for PDGFB, COL1A1-PDGFB and COL1A1, next-generation sequencing (NGS), reverse-transcriptase polymerase chain reaction (RT-PCR) and Sanger sequencing were performed. Results: There were three cases of CC-DFSP, including two females and one male. The patients were 29, 44 and 32 years old, respectively. The sites were abdominal wall, caruncle and scapula. Microscopically, they were poorly circumscribed. The spindle cells of the tumors infiltrated into the whole dermis or subcutaneous tissues, typically arranging in a storiform pattern. Immunohistochemically, the neoplastic cells exhibited diffuse CD34 expression, but were negative for S-100, SMA, and Myogenin. Loss of H3K27me3 was not observed in the tumor cells. The Ki-67 index was 10%-15%. The 3 cases were all negative for PDGFB rearrangement and COL1A1-PDGFB fusion, whereas showing unbalanced rearrangement for COL1A1. Case 1 showed a COL1A1 (exon 31)-PDGFB (exon 2) fusion using NGS, which was further validated through RT-PCR and Sanger sequencing. All patients underwent extended surgical resection. Except for case 3 with recurrence 2 years after surgical resection, the other 2 cases showed no recurrence or metastasis during the follow-up. Conclusions: FISH has shown its validity for detecting PDGFB rearrangement and COL1A1-PDGFB fusion and widely applied in clinical detection. However, for cases with negative routine FISH screening that were highly suspicious for DFSPs, supplementary NGS or at least COL1A1 break-apart FISH screening could be helpful to identify cryptic COL1A1-PDGFB fusions or other variant fusions.

Alveolar Adenoma With CD34 Diffusely Positive Stromal Cells: A Rare Case Report and Literature Review.

Alveolar adenoma (AA) is a rare type of pulmonary neoplasm showing proliferation of alveolar epithelium and septal mesenchyme. Clinically, AA is asymptomatic, benign, and usually diagnosed incidentally. Surgical excision is curative. The etiology of AA is controversial and the pathogenesis is unknown, but it is thought to stem from type II pneumocytes and fibroblasts or fibroblast-like cells. The stromal cells in AA may show rare staining for CD34. Diffuse CD34 positivity of the interstitial stromal cells has rarely been described and reviewed. Here, we report a case of AA with strong and diffuse CD34 staining in the stromal cells.

Dermatofibrosarcoma protuberans in dermatological practice. Case report

Dermatofibrosarcoma protuberans (DFSP) is a mesenchymal neoplasm of fibrohistiocytic origin of moderate malignancy. The pathogenesis of DFSP involves chromosomal translocation, which leads to the formation of a fusion protein that promotes tumor growth due to increased production of platelet growth factor (PDGF). Clinically, it begins with an asymptomatic fibrous papule or firm plaques, which gradually over the course of several years become enlarged with the formation of asymmetrical multi-nodular structure of purple or red-brown color. The standards of diagnosis is a histological examination with the detection of a poor limited infiltrate indermis of a storiform architecture consisting of monomorphic spindle cells and diffuse CD34+ staining during immunohistochemistry. Complete surgical excision is considered the gold standard of treatment. Clinical case: female patient, 35 years old with a lesion in the form of a dense plaque in right subclavian area was examined by a dermatologist. The primary diagnosis was made as "morphea". In a year a slight growth of the lesion and the appearance of small firm nodules asymmetrically along the periphery were noted. According to the results of histological and immunohistochemistry studies the diagnosis of DFSP was made, the patient was referred to an oncologist for complete tumor removal.

CD30+ Anaplastic Enteropathy-Associated T-cell Lymphoma Mimicking Crohn’s Disease

Abstract Introduction/Objective Enteropathy-associated T-cell lymphoma (EATL) is an aggressive peripheral T-cell lymphoma with a very poor prognosis. It is not uncommon for patients with EATL to present with intestinal obstruction or perforation, with the diagnosis made following surgical resection or autopsy. Although EATL is associated with celiac disease, this diagnosis may be made concomitant with EATL. The symptomology is often non-specific, particularly without a known history of celiac disease, and progression may be rapid. Methods/Case Report We describe the case of a 57 year old male who presented with several months of diarrhea, fatigue, night sweats, severe weight loss, and failure to thrive. Initial workup indicated positivity for Clostridium difficile and cryptosporidium, leading to antibiotic treatment. His symptoms persisted without significant improvement and a presumptive diagnosis of Crohn’s disease was made based on colonoscopy with biopsy and imaging that showed inflammatory changes with entero-enteric fistula formation. Further clinical decline necessitated exploratory laparotomy which revealed multiple enteric strictures, intra-loop abscesses, and necrotic ulceration necessitating segmental ileal resections. There was no associated lymphadenopathy. Microscopically, there was a dense, polymorphic lymphoid population within the bowel wall with associated mucosal ulceration and abundant necrosis. Striking anaplastic cytomorphology was present, with a heavy intratumoral eosinophilic infiltrate. Neoplastic lymphocytes were CD3+, CD30+ T cells with a CD7+, CD5-, CD4-, CD8-, CD56-, ALK- immunophenotype. The adjacent intestinal mucosa showed features of celiac disease (villous atrophy, intraepithelial lymphocytosis). Results (if a Case Study enter NA) NA Conclusion The prominent anaplastic morphology in combination with strong, diffuse CD30 expression prompted consideration of other T cell lymphomas, including anaplastic large cell lymphoma and peripheral T cell lymphoma, NOS, within the differential. The presence of coexisting histologic changes of celiac disease, dense eosinophilic infiltrate, and absence of lymphadenopathy were clues to the correct diagnosis. Notably, the frequency of CD30 expression in EATL is variable but common among cases manifesting large cell morphology.

CD34 EXPRESSION AS A SURROGATE MARKER FOR DIAGNOSIS OF INVASIVE DUCTAL CARCINOMA OF BREAST.

Background : The normal stroma of breast has enormous numbers of CD34+ brocytes therefore loss of CD34 expression in mesenchymal cells has been considered as signicant in malignant transformation and as such thought to be conclusive proof in IDC. This hypothesis leads to the identication of a new marker to diagnose cases of IDC. This study is aimed to establish the role of CD34 in diagnosis of IDC of breast. AIM: To establish the CD34 stromal expression as signicant immunohistochemical marker and to establish its efcacy as diagnostic tool to diagnose IDC. Result: A total of 50 cases of already diagnosed invasive ductal carcinoma of breast were selected and CD34 staining was performed on parafn section of all specimens. Most of the patients were in age group 35-50 years who presented with breast lumps. 50 cases of invasive ductal carcinoma were seen with 22 cases shows Lymphovascular and perineural involvement and 26 cases showed nipple areola involvement and 38 showed axillary lymph node metastasis. On histological grading of 50 malignant cases 06 cases were grade - III, 26 cases were grade- II and 18 were grade - I. Normal breast tissue was taken as internal control which show diffuse CD34 expression in stroma while there is loss of expression of CD34 in stroma in inltrating ductal carcinoma. Thereby conrms the loss of cell molecules adhesive property and signal transduction. Conclusion: There is obvious absence of expression of CD34 in malignant breast lesions. Therefore in this study we conclude that CD34 has potential to be used as surrogate diagnostic marker and management of IDC.

Predictive Patterns of Glutamine Synthetase Immunohistochemical Staining in CTNNB1-mutated Hepatocellular Adenomas.

Some hepatocellular adenoma (HCA) subtypes are characterized by different CTNNB1 mutations, leading to different beta-catenin activation levels, hence variable immunostaining patterns of glutamine synthetase (GS) expression, and different risks of malignant transformation. In a retrospective multicentric study of 63 resected inflammatory (n=33) and noninflammatory (n=30) molecularly confirmed CTNNB1-mutated b-(I)HCA, we investigated the predictive potential of 3 known GS patterns as markers for CTNNB1 exon 3, 7/8 mutations. Pattern 1 (diffuse homogenous) allowed recognition of 17/21 exon 3 non-S45 mutated b-(I)HCA. Pattern 2 (diffuse heterogenous) identified all b-(I)HCA harboring exon 3 S45 mutation (20/20). Pattern 3 (focal patchy) distinguished 12/22 b-(I)HCA with exon 7/8 mutations. In exon 3 S45 and 7/8 mutations, both b-HCA and b-IHCA showed a GS+/CD34- rim with diffuse CD34 positivity in the center of the lesion. Interobserver reproducibility was excellent for exon 3 mutations. Comparative analysis of GS patterns with molecular data showed 83% and 80% sensitivity (b-HCA/b-IHCA) and 100% specificity for exon 3 non-S45. For exon 3 S45, sensitivity was 100% for b-(I)HCA, and specificity 93% and 92% (b-HCA/b-IHCA). For exon 7/8, sensitivity was 55% for both subtypes and specificity 100% and 96% (b-HCA/b-IHCA). Preliminary data from 16 preoperative needle biopsies from the same patients suggest that this panel may also be applicable to small samples. In surgically resected HCA, 2 distinct GS patterns can reliably predict CTNNB1 exon 3 mutations, which are relevant because of the higher risk for malignant transformation. The third pattern, although specific, was less sensitive for the identification of exon 7/8 mutation, but the GS+/CD34- rim is a valuable aid to indicate either an exon 3 S45 or exon 7/8 mutation.

Characterization of Early Hepatocellular Carcinoma and High-Grade Dysplastic Nodules on Contrast-Enhanced Ultrasound: Correlation With Histopathologic Findings.

To explore the enhancement features of early hepatocellular carcinoma (HCC, including well-differentiated HCC and high-grade dysplastic nodules with a focus of HCC) and high-grade dysplastic nodules (HGDNs) on contrast-enhanced ultrasound (CEUS), correlated with the histopathologic findings. This retrospective study enrolled 81 patients with 85 pathologically confirmed hepatic lesions (69 early HCCs and 16 HGDNs). All of the hepatic lesions were examined by CEUS with SonoVue (Bracco SpA, Milan, Italy) before surgery or biopsy. The enhancement features of early HCCs and HGDNs were evaluated and compared with histopathologic findings. Thirty-eight (55.1%) early HCCs showed arterial-phase hyperenhancement (APHE). The major enhancement pattern of early HCCs was APHE without portal venous/late-phase wash-out (20 of 69 [29.0%]). Eight (11.6%) early HCCs manifested APHE. Wash-out was observed in 30 (43.5%) early HCCs. Sixteen (23.2%) early HCCs showed very-late wash-out (>120 seconds). Wash-out was not observed in all HGDNs. Of the 16 HGDNs, arterial-phase isoenhancement without portal venous/late-phase wash-out was the major enhancement pattern (n = 7 [43.8%]). The degree of CD34 expression of sinusoidal endothelial cells was more diffuse in early HCCs than in HGDNs (56.5% versus 12.5%; P = .001). Arterial-phase enhancement patterns of early HCCs on CEUS were correlated with the degree of CD34 expression (P = .039). Enhancement patterns were significantly different between early HCCs and HGDNs on CEUS. Diffuse CD34 expression of sinusoidal endothelial cells in early HCC was correlated with APHE on CEUS.

RARE-32. POLYMORPHOUS LOW-GRADE NEUROEPITHELIAL TUMOR OF THE YOUNG (PLNTY): GENETIC ANALYSIS CONFIRMS FREQUENT MAPK PATHWAY ACTIVATION

Abstract Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a recently described epileptogenic tumor characterized by oligodendroglioma-like components, aberrant CD34 expression, and genetic MAPK pathway activation through alterations such as BRAF V600E mutation, and FGFR2-KIAA1598/CTNNA3 and FGFR3-TACC3 fusions. We report the molecular profiling of PLNTY in 9 patients, 7 female: 2 male, median age at diagnosis of 16 years (range, 5–34). All tumors were supratentorial with diagnostic morphological features of PLNTY including oligodendroglioma-like areas and strong diffuse CD34 immunostaining. Four (of 9; 44%) tumors were positive for BRAF V600E immunostain, indicating the presence of a BRAF V600E mutation. The 6 cases evaluated for IDH status were negative by IDH1-R132H immunostain (n=5; 3 BRAF V600E-negative and 2 BRAF V600E-positive) or by NGS (n=1; BRAF V600E-negative). Oncoscan chromosomal microarray performed in 5 BRAF V600E-negative tumors showed recurrent copy number changes including gain of whole chromosomes 5, 7, 8, 9, 12, 18, 19, 20, 21 and X, and loss of chromosomes 1, 2, 10q, 13, 22 and Xq. The 10q losses (n=2) were highly suggestive of an FGFR2-KIAA1598 and of a potentially novel FGFR2 underlying fusion event in one case each. Custom targeted neuro-oncology DNA and RNA NGS panel performed in 2 cases revealed a fusion similar to fusions previously reported in pilocytic astrocytoma: one with a KIAA1549-BRAF (exon 15-exon 9) fusion associated with a 7q34 ~785 kilobase deletion rather than the characteristic ~2 megabase duplication seen in pilocytic astrocytoma, and another with a QKI-NTRK2 (exon 6-exon 15) fusion associated with a 9q21 ~191 kilobase duplication disrupting NTRK2. The KIAA1549-BRAF fusion-positive case also had a TP53 mutation with loss of whole chromosome 17, suggesting TP53 complete inactivation. This study confirms that PLNTY is a low-grade neuroepithelial tumor with frequent MAPK pathway activation and expands the spectrum of MAPK activating alterations observed in PLNTY.

Next generation sequencing for GNAS uncovers CD34 as a sensitive marker for intramuscular myxoma

BackgroundIntramuscular myxoma is a soft tissue myxoid tumor with a broad morphological differential diagnosis and recent developments have led to the identification of markers that can exclude some, but not all, differential diagnostic entities. However, a sensitive confirmatory marker for intramuscular myxoma has not been clearly identified. Since there is some evidence that mutations in the GNAS gene could be such a marker, we evaluated our results of next-generation sequencing testing for GNAS mutations performed in recent years on our series of intramuscular myxoma. Materials and methodsNext-generation sequencing was performed on 10 cases of intramuscular myxoma diagnosed between 2015 and 2019, using either the TruSight Tumor 26 panel or an in-house developed 97 cancer gene panel. Additionally, immunohistochemistry for CD34 was performed on all cases. ResultsAll intramuscular myxomas showed a diffuse and strong expression of CD34 and a GNAS mutation was found in 88% of cases, making this a very sensitive positive test for the diagnosis of intramuscular myxoma. ConclusionsUnder the condition that contemporary next-generation sequencing is applied as testing method, searching for GNAS mutations is a very sensitive confirmatory test for the diagnosis of intramuscular myxoma, obviating the necessity to perform tests that exclude other entities by the virtue of their negative result. The molecular tests results also identified strong and diffuse CD34 expression as a sensitive, albeit non-specific, marker for intramuscular myxoma.

Adamantinoma-Like Ewing’s Family Tumor of the Sino Nasal Region: A Case Report and a Brief Review of Literature

Ewing's sarcoma family of tumors (EFTs) are malignant mesenchymal tumors with a predilection for bone and soft tissue. They are characterized by their monomorphic small blue round cell morphology. However rare morphologic variants of EFTs can also show overt epithelial differentiation in the form of squamoid differentiation along with strong cytokeratin expression. This particular subset of EFTs are known as adamantinoma-like EFTs which can be difficult to differentiate from epithelial head and neck malignancies. Here we report a case of sinonasal adamantinoma-like EFT in an 18-year-old male patient. The lesion differed from a typical EFT by means of overt squamoid differentiation which showed a basaloid appearance with peripheral palisading. The immunohistochemistry was positive for pan-cytokeratin, p40, p63, ERG, FLI1, and CK5/6. It was negative for actin, desmin, and WT-1. Initial diagnosis of a basaloid squamous cell carcinoma was made. Further molecular studies were also done due to the complex presentation of the tumor. EWSR testing with break-apart analysis confirmed EWSR1 and FLI1 rearrangements. Further confirmation was done with RT-PCR. The case was found to be positive for EWS-FLI-1 translocation. The revised immunohistochemistry panel showed CD99, ERG, FLI1, and synaptophysin positivity. The lesion was reclassified as an adamantinoma-like ES. Our case reinforces the fact that a subset of EFTs can show histomorphologic and immunohistochemical features of aberrant epithelial differentiation. These cases are difficult to differentiate from usual epithelial malignancies which occur in this region. This diagnostic pitfall can be avoided by the inclusion of CD99 and/or FLI1 in the immunohistochemical assessment of any round cell malignancy at any anatomic location. A strong and diffuse CD99 positivity should prompt molecular testing for the presence of EWSR1 gene rearrangements.