The American Journal of Surgical Pathology最新文献

Although follicular lymphoma (FL) is usually graded as FL1-2, FL3A, and FL3B, some borderline cases can be observed and led us to investigate the clinicopathologic diversity of grade 3 FL (FL3). Among 2449 FL patients enrolled in Lymphoma Study Association (LYSA) trials, 1921 cases with sufficient material underwent a central pathologic review. The resulting diagnoses comprised 89.6% FL1-2 (n=1723), 7.2% FL3A (n=138), and 0.5% purely follicular FL3B (n=9). The remaining 51 unclassifiable cases (2.7%) exhibited high-grade features but did not meet WHO criteria for either FL3A or FL3B; and were considered as "unconventional" high-grade FL (FL3U). FL3U morphological pattern consisted of nodular proliferation of large cleaved cells or small-sized to medium-sized blast cells. Compared with FL3A, FL3U exhibited higher MUM1 and Ki67 expression, less BCL2 breaks and more BCL6 rearrangements, together with a higher number of cases without any BCL2, BCL6 or MYC rearrangement. FL3U harbored less frequent mutations in BCL2, KMT2D, KMT2B, and CREBBP than FL3A. MYC and BCL2 were less frequently mutated in FL3U than FL3B. Rituximab cyclophosphamide, doxorubicin, vincristine, and prednisone treated FL3U patients had a worse survival than FL1-2 patients with similar follicular lymphoma international prognostic index and treatment. These results suggest that high-grade FLs encompass a heterogeneous spectrum of tumors with variable morphology and genomic alterations, including FL3U cases that do not strictly fit WHO criteria for either FL3A or FL3B, and display a worse outcome than FL1-2. The distinction of FL3U may be useful to allow a better comprehension of high-grade FLs and to design clinical trials.

Locally advanced breast cancer is typically treated with neoadjuvant chemotherapy to decrease tumor size and optimize surgical results. Cases of pathologic complete response, are associated with favorable long-term outcomes. The American Joint Committee on Cancer (AJCC) defines pathologic complete response as a lack of residual invasive disease in the breast or lymph nodes or only residual ductal carcinoma in situ. Three studies have examined the unique pattern of postneoadjuvant pure or predominantly pure intralymphatic carcinoma. These studies are small and the prognosis associated with this disease pattern is still unclear. The current study aims to describe clinicopathologic findings associated with pure and predominantly pure intralymphatic carcinoma postneoadjuvant chemotherapy. Electronic medical records were searched to identify patients treated with postneoadjuvant mastectomy between 2010 and 2017. Cases were included if they met the previously defined definitions for pure or predominantly pure intralymphatic carcinoma. Of 479 postneoadjuvant mastectomies, 5 patients had pure intralymphatic carcinoma and 6 patients had predominantly pure. Overall, 50% (3/6) of patients with predominantly pure pattern died of metastatic disease within 14 months of mastectomy, whereas 1 patient with pure intralymphatic carcinoma (ypN0) died of metastatic disease 25 months postmastectomy, revealing a better prognosis associated with pure intralymphatic carcinoma when compared with predominantly pure. The diligent gross examination is required to identify patients with both patterns of residual disease. A standardized approach to incorporating lymphovascular invasion into postneoadjuvant staging may be useful from both a clinical and research perspective. The published case numbers remain small and understanding the true clinical significance still depends on additional studies.

Pyloric gland metaplasia (PGM) is a histopathologic change usually seen after inflammatory injury and, although described in association with inflammatory bowel disease (IBD) and particularly Crohn disease (CD), its significance is still debated. We evaluated long-term correlates of PGM in a large cohort of 601 intestinal specimens, 227 (37.8%) biopsies, and 374 (62.2%) resections, from 567 different patients, 328 (57.8%) male and 239 (42.2%) female, with a mean age of 43.4±15.8 years. During mean clinical follow-up of 83.5±48.1 months, 511 (90.1%) patients were diagnosed with IBD, 457 (89.4%) with CD, and 53 (10.4%) with ulcerative colitis. In multivariate analysis, IBD patients with PGM were younger (P<0.001) and more often had severely active inflammation (P=0.002) compared with non-IBD patients, whereas, among IBD patients, those with ulcerative colitis were more likely to have PGM in a biopsy (P<0.001) or in the colorectum (P=0.009), compared with CD patients. Kaplan-Meier analyses showed that incidental PGM in a biopsy was more likely to predict IBD in patients younger than 50 years (P<0.001) and those without a history of bowel surgery (P<0.001) and also more likely to signify CD in patients younger than 50 years (P=0.004), those without a history of bowel surgery (P=0.020), and when identified in the small intestine (P=0.032). In conclusion, intestinal PGM warrants a high suspicion for IBD and specifically CD, however, it should be interpreted with caution, especially in older patients or those with a history of prior intestinal surgery and in colorectal biopsies or specimens lacking severely active inflammation.

Distinguishing between poorly differentiated urothelial carcinoma and high-grade prostatic adenocarcinoma is a common challenge in genitourinary pathology, particularly when the tumor involves the bladder neck or prostatic urethra. Clinically, the distinction between these 2 tumors can also be difficult. Proper diagnosis in these patients is essential as they have differing prognoses and clinical management. GATA3 is thought to be a sensitive and relatively specific marker of urothelial carcinoma. However, there is scant data regarding GATA3 labeling of high-grade prostatic adenocarcinoma. The aim of this study is to describe rare cases with strong aberrant GATA3 staining in prostatic adenocarcinoma as a potential diagnostic pitfall. We identified 9 cases of prostatic adenocarcinoma with aberrant positive GATA3 staining from 2015 to 2020 as part of a large consultation service at our institution. All 9 cases were grade group 5, 8 had a Gleason score of 5+5=10 and 1 had a score of 4+5=9. Five of the cases were from the prostate, 3 from the urinary bladder, and 1 from the prostatic urethra. All cases were morphologically typical of high-grade prostatic adenocarcinoma, although were sent for consultation due to uncertainty in the diagnosis. GATA3 positivity was strong, diffuse in 4 cases; strong, patchy in 2 cases and strong, focal in 3 cases. All cases were positive for NKX3.1, 6 positive for p501s, and 6 positive for PSA, with 7/9 cases showing expression of at least 2 prostate-specific markers. The current study describes that rare cases of prostatic adenocarcinoma can show focal or diffuse strong staining for GATA3. In order to avoid this diagnostic pitfall, undifferentiated carcinomas involving the prostate, bladder neck, or trigone should be evaluated not only with GATA3 but also prostate-specific markers.

Since its original description in 1995, the concept of sclerosing epithelioid fibrosarcoma (SEF) as a distinctive tumor has evolved in the literature. Subsequent studies suggested that the presence of low grade fibromyxoid sarcoma (LGFMS)-like zones, occasional FUS gene rearrangements, and immunoreactivity for MUC4 all pointed to a close inter-relationship with LGFMS; however, more recent studies showed that SEF is genetically distinct from LGFMS with predominantly EWSR1-CREB3L1 fusion and complex secondary genomic alterations. To better understand the relationship between these tumors, we studied 51 cases of SEF, the largest reported series to date, and directly compared them to a previously published series of LGFMS from the same institution. The male-to-female ratio was 1.4:1 with a median age of 45 years. Tumors occurred primarily in the lower extremity (12), intra-abdominal area/visceral organs (9) and chest wall/paraspinal region (9) with a median size of 8.2 cm. The median follow-up was 49 months in 45 patients: 12 developed local recurrences and 36 developed metastases, mainly to lung and bone. Molecular studies showed EWSR1 gene rearrangement in 13 cases, 3' deletion of EWSR1 in 6, monosomy for EWSR1 in 2; FUS gene rearrangements in 3; EWSR1-CREB3L1 fusion in 7; EWSR1-CREB3L2 fusion in 1; and YAP1-KMT2A fusion in 2. Overall survival of SEF was significantly less compared with LGFMS (P≤0.0001). These results indicate that SEF is a distinct sarcoma that behaves more aggressively than LGFMS with a shorter survival, higher metastatic rate, and greater propensity to involve deep soft tissue and bone.

Lymphadenopathy is common in patients with immunoglobulin G4-related disease (IgG4-RD). However, the described histopathologic features of IgG4-related lymphadenopathy have been shown to be largely nonspecific. In an attempt to identify features specific for nodal IgG4-RD we examined the histopathologic features of lymph nodes from 41 patients with established IgG4-RD, with comparison to 60 lymph nodes from patients without known or subsequent development of IgG4-RD. An increase in immunoglobulin (Ig) G4-positive plasma cells >100/HPF and IgG4/IgG ratio >40% was identified in 51% of IgG4-RD cases and 20% of control cases. Localization of increased IgG4-positive plasma cells and IgG4/IgG ratio to extrafollicular zones was highly associated with IgG4-RD, particularly when identified in regions of nodal fibrosis (P<0.0001; specificity: 98.3%), or in the context of marked interfollicular expansion (P=0.022; specificity: 100%). Other features characteristic of IgG4-RD included frequent eosinophils associated with IgG4-positive plasma cells, phlebitis (P=0.06), and perifollicular granulomas (P=0.16). The presence of an isolated increase in intrafollicular IgG4-positive plasma cells and IgG4/IgG ratio was more frequently present in control cases than IgG4-RD (P<0.0001). This study confirms that increased IgG4-positive plasma cells and IgG4/IgG ratio are neither sensitive nor specific for the diagnosis of IgG4-related lymphadenopathy, and most described morphologic patterns are nonspecific. In contrast, nodal involvement by IgG4-rich fibrosis akin to extranodal IgG4-RD or diffuse interfollicular expansion by IgG4-positive plasma cells are highly specific features of true IgG4-related lymphadenopathy. Our findings provide for a clinically meaningful approach to the evaluation of lymph nodes that will assist pathologists in distinguishing IgG4-related lymphadenopathy from its mimics.

Postchemotherapy histiocyte-rich pseudotumor is a rare event in lymphoma patients and can cause elevated metabolic activity on positron emission tomography-computed tomography scan mimicking residual tumor. Here, we reported 11 lymphoma cases showing mass-like lesions with increased fluorodeoxyglucose uptake after chemotherapy. These postchemotherapy lesions occurred in various anatomic sites including spleen, mediastinum, lymph node, and other tissue locations, concerning for refractory or residual lymphoma. Their median size was 2.7 cm (range, 1.4 to 7.7 cm) and the median standardized uptake value on positron emission tomography-computed tomography was 10.6 (range, 5.2 to 13.8). Histologic examination of these lesions demonstrated reactive changes mainly composed of histiocyte-rich proliferation without viable lymphoma. Fat necrosis, cholesterol cleft, and calcium deposit were also commonly observed. After biopsies, 3 patients received additional chemotherapy, 2 had stem cell transplant with adjuvant chemotherapy or radiation, 1 had surgical excision, and the remaining 5 patients did not receive any further treatment. Follow-up imaging studies showed the resolved or decreased fluorodeoxyglucose activities in all patients including those without additional treatments, consistent with benign/reactive nature of these pseudotumor lesions. This study illustrates postchemotherapy mass-like lesions with elevated metabolic activity do not always represent residual disease and provides awareness of correlation between radiologic and histologic features of these lesions to avoid misinterpretation and overtreatment of lymphoma patients after chemotherapy.

CTNNB1 mutations and aberrant β-catenin expression have adverse prognosis in endometrial endometrioid carcinoma, and recent evidence suggests a prognostic role of β-catenin in ovarian endometrioid carcinoma. Thus, we aimed to determine the prognostic value of the CTNNB1 mutational status, and its correlation with β-catenin expression, in a well-annotated cohort of 51 ovarian endometrioid carcinomas. We performed immunohistochemistry for β-catenin and developed an 11-gene next-generation sequencing panel that included whole exome sequencing of CTNNB1 and TP53. Results were correlated with clinicopathologic variables including disease-free and disease-specific survival. Tumor recurrence was documented in 14 patients (27%), and cancer-related death in 8 patients (16%). CTNNB1 mutations were found in 22 cases (43%), and nuclear β-catenin in 26 cases (51%). CTNNB1 mutation highly correlated with nuclear β-catenin (P<0.05). Mutated CTNNB1 status was statistically associated with better disease-free survival (P=0.04, log-rank test) and approached significance for better disease-specific survival (P=0.07). It also correlated with earlier International Federation of Gynecology and Obstetrics stage (P<0.05). Nuclear β-catenin, TP53 mutations, age, ProMisE group, surface involvement, tumor grade and stage also correlated with disease-free survival. There was no association between membranous β-catenin expression and disease-free or disease-specific survival. CTNNB1 mutations and nuclear β-catenin expression are associated with better progression-free survival in patients with OEC. This relationship may be in part due to a trend of CTNNB1-mutated tumors to present at early stage. β-catenin immunohistochemistry may serve as a prognostic biomarker and a surrogate for CTNN1B mutations in the evaluation of patients with ovarian endometrioid neoplasia, particularly those in reproductive-age or found incidentally without upfront staging surgery.

Oncocytic mucoepidermoid carcinoma (OMEC) is a rare but diagnostically challenging variant of mucoepidermoid carcinoma (MEC). OMEC is notable for differential diagnostic considerations that are raised as a result of overlap with other benign and low-grade oncocytic salivary gland tumors. Diffuse and strong immunoreactivity of p63 protein may be useful in distinguishing OMEC from its mimics. However, focal p63 staining can be present in benign oncytomas. Presence of mucin-containing cells, mucinous cystic formation, and foci of extravasated mucin are considered a hallmark of MEC. True mucocytes may be, however, very few and hardly discernable in OMECs. Recent evidence has shown that most MECs harbor gene fusions involving MAML2. A retrospective review of archived pathology files and the authors' own files was conducted to search for "low-grade/uncertain oncocytic tumor," "oncocytoma," and "oncocytic carcinoma" in the period from 1996 to 2019. The tumors with IHC positivity for p63 and/or p40, and S100 negativity, irrespective of mucicarmine staining, were tested by next-generation sequencing using fusion-detecting panels to detect MAML2 gene rearrangements. Two index cases from consultation practice (A.S. and A.A.) of purely oncocytic low-grade neoplasms without discernible mucinous cells showed a CRTC1-MAML2 fusion using next-generation sequencing, and were reclassified as OMEC. In total, 22 cases of oncocytic tumors, retrieved from the authors' files, and from the Salivary Gland Tumor Registry, harbored the MAML2 gene rearrangements. Presence of mucocytes, the patterns of p63 and SOX10 immunopositivity, and mucicarmine staining were inconsistent findings. Distinguishing OMEC devoid of true mucinous cells from oncocytoma can be very challenging, but it is critical for proper clinical management. Diffuse and strong positivity for p63 and visualization of hidden mucocytes by mucicarmine staining may be misleading and does not always suffice for correct diagnosis. Our experience suggests that ancillary studies for the detection of MAML2 rearrangement may provide useful evidence in difficult cases.