Prostate-Specific Membrane Antigen (PSMA) Expression Predicts Need for Early Treatment in Prostate Cancer Patients Managed with Active Surveillance.

Metabolic dysregulation is an early event in carcinogenesis. Here, we examined the expression of enzymes involved in de novo lipogenesis (ATP-citrate lyase: ACLY), glucose uptake (Glucose Transporter 1: GLUT1), and folate-glutamate metabolism (Prostate-Specific Membrane Antigen: PSMA) as potential biomarkers of risk for early prostate cancer progression. Patients who were managed initially on active surveillance with a Gleason score of 6 or a low-volume Gleason score of 7 (3 + 4) were accrued from a prostate cancer diagnostic assessment program. Patients were asked to donate their baseline diagnostic biopsy tissues and permit access to their clinical data. PSMA, GLUT1, and ACLY expression were examined with immunohistochemistry (IHC) in baseline biopsies, quantitated by Histologic Score for expression in benign and malignant glands, and compared with patient time remaining on active surveillance (time-on-AS). All three markers showed trends for elevated expression in malignant compared to benign glands, which was statistically significant for ACLY. On univariate analysis, increased PSMA and GLUT1 expression in malignant glands was associated with shorter time-on-AS (HR: 5.06, [CI 95%: 1.83-13.94] and HR: 2.44, [CI 95%: 1.10-5.44], respectively). Malignant ACLY and benign gland PSMA and GLUT1 expression showed non-significant trends for such association. On multivariate analysis, overexpression of PSMA in malignant glands was an independent predictor of early PC progression (p = 0.006). This work suggests that the expression of metabolic enzymes determined by IHC on baseline diagnostic prostate biopsies may have value as biomarkers of risk for rapid PC progression. PSMA may be an independent predictor of risk for progression and should be investigated further in systematic studies.

18F-DCFPyL (PSMA) PET as a radiotherapy response assessment tool in metastatic prostate cancer.

Background: Prostate Specific Membrane Antigen (PSMA) - positron emission tomography (PET) guides metastasis-directed radiotherapy (MDRT) in prostate cancer (PrCa). However, its value as a treatment response assessment tool after MDRT remains unclear. Importantly, there is limited understanding of the potential of radiotherapy (RT) to alter PSMA gene (folate hydrolase 1; FOLH1) expression. Methodology: We reviewed a series of 11 men with oligo-metastatic PrCa (25 metastasis sites) treated with MDRT before re-staging with 18F-DCFPyL (PSMA) PET upon secondary recurrence. Acute effects of RT on PSMA protein and mRNA levels were examined with qPCR and immunoblotting in human wild-type androgen-sensitive (LNCap), castrate-resistant (22RV1) and castrate-resistant neuroendocrine (PC3 and DU145) PrCa cell lines. Xenograft tumors were analyzed with immunohistochemistry. Further, we examined PSMA expression in untreated and irradiated radio-resistant (RR) 22RV1 (22RV1-RR) and DU145 (DU145-RR) cells and xenografts selected for survival after high-dose RT. Results: The majority of MDRT-treated lesions showed lack of PSMA-PET/CT avidity, suggesting treatment response even after low biological effective dose (BED) MDRT. We observed similar high degree of heterogeneity of PSMA expression in both human specimens and in xenograft tumors. PSMA was highly expressed in LNCap and 22RV1 cells and tumors but not in the neuroendocrine PC3 and DU145 models. Single fraction RT caused detectable reduction in PSMA protein but not in mRNA levels in LNCap cells and did not significantly alter PSMA protein or mRNA levels in tissue culture or xenografts of the other cell lines. However, radio-resistant 22RV1-RR cells and tumors demonstrated marked decrease of PSMA transcript and protein expression over their parental counterparts. Conclusions: PSMA-PET may be a promising tool to assess RT response in oligo-metastatic PrCa. However, future systematic investigation of this concept should recognize the high degree of heterogeneity of PSMA expression within prostate tumors and the risk for loss of PSMA expression in tumor surviving curative courses of RT.

Desmoplastic small round cell tumor involving the uterine cervix: The first reported case in the literature, and brief review of gynecologic presentations.

Background: Desmoplastic small round cell tumors are exceedingly rare, usually involve abdominal organs and predominantly affect male patients. We describe the first reported case arising from the uterine cervix and provide a summary of 20 previously reported cases involving gynecologic organs. Case: A 54 year-old was diagnosed with a rapidly growing 13 cm desmoplastic small round cell tumor of the cervix. She was treated through a multimodal approach involving neoadjuvant chemotherapy and surgery. She subsequently recurred, and this was successfully treated with radiation therapy. She is well and without evidence of disease 22 months after initial diagnosis. Conclusion: We report successful treatment through multidisciplinary and multimodal management. This can guide management of future patients as no gold-standard treatment has yet been described.

Estrogen receptor-positive adenocarcinoma of the cervix presenting during pregnancy: Two case reports and review of the literature.

The incidence of adenocarcinoma of the cervix in pregnancy is exceptionally rare, and thus there is no consensus on its management. Here, we report two cases of adenocarcinoma of the cervix diagnosed in the context of pregnancy. In our first case, a patient referred to colposcopy for atypical glandular cells of undetermined significance was subsequently diagnosed with well differentiated endocervical adenocarcinoma on cone biopsy. Just prior to the cone biopsy, she was incidentally found to have a first trimester pregnancy loss. The patient subsequently underwent a radical hysterectomy and bilateral sentinel lymph node dissection. Final pathology revealed a stage 1B1 (FIGO 2009) well differentiated adenocarcinoma of the cervix. Interestingly, the tumour was positive for estrogen receptor, which is unusual for cervical adenocarcinoma. In our second case, a patient presented with a pedunculated, exophytic cervical neoplasm at 31 weeks GA with self-limiting antepartum hemorrhage. The primary lesion measured 52 mm in diameter on MRI and was amputated at the base during the patient's elective repeat cesarean section. Final pathology revealed a stage IB2 (FIGO 2009) mucinous adenocarcinoma of the cervix. The patient subsequently underwent a radical hysterectomy and bilateral pelvic lymph node dissection 17 weeks after initial presentation. The depth of invasion was 2.2 mm, restricted to the inner third of the cervical wall, and there was no lymphovascular space invasion in the surgical specimen. Surgical margins, parametria, and lymph nodes were all negative for adenocarcinoma. This tumour was also found to be estrogen receptor/progesterone receptor (ER/PR) positive, again unusual for cervical adenocarcinoma. P16 was strongly positive and HPV DNA studies were also positive for human papilloma virus 18. The patient received adjuvant external beam radiotherapy to the pelvis and currently remains in remission.

Breast implant-associated EBV-positive diffuse large B-cell lymphoma: Two case reports and literature review.

Lymphomas associated with breast implants are mostly of the T-cell type. They are predominantly anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALK-negative ALCL) characterized by CD30 positivity universally. Whilst the majority of primary breast lymphomas occurring in the absence of breast implants are of B-cell origin, there are few cases of implant-associated B-cell lymphomas reported to date in the literature, a subset of which are diffuse large B-cell lymphoma (DLBCL). Given the rarity of this entity, we describe two cases of breast implant-associated DLBCL. Both patients developed Epstein-Barr Virus (EBV)-positive large cell lymphoma of B-cell origin confined to the implant capsule with no evidence of systemic lymphoma. Considering the association with EBV, the activated B-cell phenotype and the presumed chronic inflammatory environment associated with the implant capsule, these might represent forms of DLBCL associated with chronic inflammation (DLBCL-CI) or fibrin-associated DLBCL (FA-DLBCL). Treatment included implant removal with total capsulectomy, and for one of the cases adjuvant systemic chemotherapy. Recognizing this rare type of breast implant-associated B-cell lymphoma could improve our understanding of this entity and hence develop appropriate management strategies.

An approach to small lymph node biopsies: pearls and pitfalls of reporting in the real world.

Recent advances in interventional radiology have resulted in the utilization of small lymph node biopsies, including fine-needle aspiration (FNA) and core needle biopsy (CNB) as an initial diagnostic tool in hematopathology. A major challenge to the utilization of FNA and CNB is the limited-to-scant tissue often available. We propose delegation of the task of handling biopsy specimens to the laboratory staff by the biopsy operators, in order to optimize the utilization of the specimen. Furthermore, in order to effectively diagnose hematolymphoid neoplasms a variety of ancillary tests including immunohistochemistry, flow cytometry, molecular analysis, florescence in situ hybridization (FISH) are necessary. We propose morphological evaluation coupled with careful utilization of ancillary studies along with clinical correlation to approach the correct diagnosis. Our morphological assessment considers the types of proliferating cell population: mainly small cells, sheets of large cells, or scattered large cells among small cells. This is followed by employment of the corresponding immunopanel to assess the differential diagnosis in each of the three categories. We also elaborate on the importance for pathologists to become proficient in understanding the limitations of small tissue biopsies as well as the differences in interpretation, and wording their reports to help clinicians and direct them to further investigate and/or to re-biopsy when necessary.

A BERT model generates diagnostically relevant semantic embeddings from pathology synopses with active learning.

Background: Pathology synopses consist of semi-structured or unstructured text summarizing visual information by observing human tissue. Experts write and interpret these synopses with high domain-specific knowledge to extract tissue semantics and formulate a diagnosis in the context of ancillary testing and clinical information. The limited number of specialists available to interpret pathology synopses restricts the utility of the inherent information. Deep learning offers a tool for information extraction and automatic feature generation from complex datasets. Methods: Using an active learning approach, we developed a set of semantic labels for bone marrow aspirate pathology synopses. We then trained a transformer-based deep-learning model to map these synopses to one or more semantic labels, and extracted learned embeddings (i.e., meaningful attributes) from the model's hidden layer. Results: Here we demonstrate that with a small amount of training data, a transformer-based natural language model can extract embeddings from pathology synopses that capture diagnostically relevant information. On average, these embeddings can be used to generate semantic labels mapping patients to probable diagnostic groups with a micro-average F1 score of 0.779 Â ± 0.025. Conclusions: We provide a generalizable deep learning model and approach to unlock the semantic information inherent in pathology synopses toward improved diagnostics, biodiscovery and AI-assisted computational pathology.

Low-grade serous carcinoma (LGSC): A Canadian multicenter review of practice patterns and patient outcomes.

OBJECTIVE: Patients with advanced low-grade serous carcinoma (LGSC) have poor long-term survival rates. As a rare histotype, there are uncertainties regarding the use of current therapies. Thus, we studied practice patterns and treatment outcomes as part of a national initiative to better understand and improve the care of women with advanced LGSC. METHODS: This retrospective cohort study was conducted in 5 Canadian referral institutions from 2000 to 2016. Data collection and pathology reporting were standardized. Outcome measures included overall survival (OS), progression-free survival (PFS), progression-free intervals (PFI), and time to next treatment (TTNT). Cox regression analysis was used to evaluate the effects of clinical and pathologic factors on outcomes and prognosis. RESULTS: There were 134 patients (stage II-IV) with a median follow-up of 32.4 months (range 1.6-228). Four primary treatments were compared across institutions: 1) surgery followed by chemotherapy (56%), 2) neoadjuvant chemotherapy (NACT) followed by surgery (27%), 3) surgery alone (9%), and 4) surgery followed by anti-hormone therapy (4%). Primary platinum/paclitaxel chemotherapy was used in 81%. Patients treated with NACT had worse PFS. Multivariable Cox regression analysis identified lesser residual disease, younger age, and primary peritoneal origin as variables significantly associated with better OS/PFS (p < 0.03). One institution had significantly better PFS than the others (p = 0.025), but this finding could be related to a higher frequency of primary peritoneal LGSC. PFI and TTNT intervals in patients with relapsed disease were not significantly different after the first relapse irrespective of treatment type. CONCLUSIONS: There are notable differences in practice patterns across Canada. This underscores the need for ongoing strategies to measure, evaluate and achieve optimal patient outcomes for women with advanced LGSC.

Interobserver Agreement for Mismatch Repair Protein Immunohistochemistry in Endometrial and Nonserous, Nonmucinous Ovarian Carcinomas.

Immunohistochemistry (IHC) for mismatch repair (MMR) proteins is an established test to identify Lynch syndrome (LS) in patients with colorectal cancer and is being increasingly used to identify LS in women with endometrial and/or nonserous ovarian cancer (OC). We assessed interobserver agreement in the interpretation of MMR-IHC on endometrial and ovarian carcinomas. The study consisted of 73 consecutive endometrial cancers (n=48) and nonserous, nonmucinous epithelial OCs (n=25). Six pathologists from 2 cancer centers, one with and the other without, previous experience in interpreting MMR-IHC, evaluated MLH1, MSH2, MSH6, and PMS2 stains. Before the study, an experienced pathologist led a review of 9 teaching cases. A decision tool was developed as a guide in MMR-IHC interpretation. Staining was interpreted as intact, deficient, or equivocal for each protein. Interobserver agreement for the patient MMR status was categorized as "almost perfect" with κ=0.919 (95% CI, 0.863-0.976). All observers were in agreement in 66 (92%) tumors. Four of the less experienced pathologists had at least 1 discrepant interpretation. There were 6 discordant cases: 3 MMR-deficient cases and 2 MMR-intact cases by majority opinion were called equivocal by at least 1 observer, and 1 MMR-deficient case by majority opinion was interpreted as MMR intact by 1 pathologist. Only the latter case (1/73 patients, 1.4%) had an unequivocal disagreement that could affect patient management. Issues associated with discordant interpretation included heterogeneous staining, intratumoral lymphocytes, regional reduced internal control tissue staining, and scattered absent/weak staining adjacent to tumor cells with strong nuclear staining.

Pulmonary Intravascular B-Cell Lymphoma with Angiotropism/Angioinvasion Mimicking Interstitial Lung Disease: A Clinical Dilemma and Potential Diagnostic Challenge.

Intravascular large B cell lymphoma (IVLBCL) is a rare type of extranodal diffuse large B-cell lymphoma. Patients typically present with nonspecific findings, particularly bizarre neurologic symptoms, fever, and skin lesions. IVLBCL with primary lung presentation is very rare and difficult to diagnose. The authors report a case of a 75-year-old male who presented with neurological symptoms and showed diffuse pulmonary ground glass opacities on computed tomography scan (CT scan). Surgical lung biopsy was performed. Light microscopic examination of the specimen showed diffuse alveolar septal widening caused by neoplastic lymphocytes, which were positive for CD20. These atypical lymphoid cells also demonstrated angiotropism/angioinvasion of the medium sized pulmonary vessels. The patient was diagnosed with IVLBCL and underwent chemotherapy. The patient is still alive 12 months after diagnosis.

Microsatellite Genotyping to Distinguish Somatic ß-HCG Secreting Carcinoma from Epithelioid Trophoblastic Tumor.

Objective. Morphologically, ß-HCG secreting somatic carcinoma can be difficult to distinguish from epithelioid trophoblastic tumors (ETT). However, their distinction is critical due to their potentially differing prognoses and choice of chemotherapy. Presence of biparental alleles in ETT can be identified with molecular testing. We describe a patient who presented with metastatic carcinoma and elevated serum ß-HCG and contrast this to an ETT in another patient. Data and Results. A 32-year-old female with recent possible miscarriage presented with pulmonary emboli and was found to have an increased serum ß-HCG, a retroduodenal mass, and multiple nodules in her lungs, liver, and para-aortic lymph nodes. Biopsy showed a ß-HCG and p63 positive epithelioid neoplasm with otherwise noncontributory immunohistochemistry. Molecular testing for biparental alleles in repeated length polymorphisms was negative, consistent with somatic origin. The second patient was a 35-year-old pregnant female with increased serum ß-HCG and a uterine epithelioid tumor positive for ß-HCG. Clinical and pathologic findings were characteristic of ETT and molecular testing was not required. These 2 cases illustrate that ß-HCG secreting tumors of different etiologies may have similar appearances, and when clinical and/or IHC findings are inconclusive, molecular testing may be useful.

Interobserver agreement for assessing invasion in stage 1A vulvar squamous cell carcinoma.

Invasive squamous cell carcinoma of the vulva with ≤1 mm stromal invasion is classified as stage 1A. Cancer staging systems state that the depth of invasion should be measured from the epithelial-stromal junction of the adjacent most superficial dermal papilla to the deepest point of the invasive tumor. Measurement of the depth of invasion guides patient management. Even though this measurement is critical, no studies have reported the reliability among pathologists for determining the cutoff point of ≤1 mm stromal invasion in vulvar cancer. We assessed agreement among pathologists for determining whether a vulvar tumor is invasive, for the depth of invasion, and for tumor thickness. Forty-five cases of vulvar squamous cell carcinoma with a depth of invasion of ≤5 mm were chosen. Eleven gynecologic pathologists independently reviewed the slides and, for a subset of cases, pictorially recorded measurements on photographs. The number of cases that were reported as invasive by the 11 pathologists ranged from 21 to 44. The number of cases that were reported as showing a depth of invasion of ≤1 mm ranged from 7 to 27. Eight pathologists provided measurements for all lesions reported as invasive, the remaining 3 pathologists stated that they were unable to measure 2, 7, and 16 lesions, respectively. Mean κ for diagnosing vulvar carcinoma as invasive was 0.24 and for measuring the depth of invasion and thickness was 0.51 and 0.49, respectively. There was only fair agreement in determining whether the lesion was invasive. In cases in which pathologists agreed upon the diagnosis of invasion, agreement on depth was moderate. When using the recommended cancer staging method, interpretation of the location of the most superficial dermal papilla varied among pathologists. Measuring thickness did not improve agreement. This is the first study that has assessed the reliability of the diagnosis of invasion in vulvar cancer among gynecologic pathologists, the interobserver agreement for reporting the critical 1 mm threshold of depth of stromal invasion, and the way in which the International Federation of Gynecology and Obstetrics method is used by pathologists.

Do deeper sections increase the frequency of detection of serous tubal intraepithelial carcinoma (STIC) in the "sectioning and extensively examining the FIMbriated end" (SEE-FIM) protocol?

Studies have suggested serous tubal intraepithelial carcinoma (STIC) of the fallopian tube to be a putative precursor to ovarian and peritoneal serous carcinoma. It has been recommended that resected fallopian tube specimens should be rigorously examined for STIC, especially in women at high risk of serous carcinoma, such as those with BRCA mutations or with a strong family history. The SEE-FIM protocol allows for the greatest surface area of the tube to be histologically assessed. There have been suggestions that multiple deeper sections should be examined if the initial hematoxylin and eosin (H&E) sections are negative; however, whether this identifies more cases of STIC has not rigorously examined. We examined deeper sections from 56 cases of pelvic carcinoma in which the initial H&E sections of the fallopian tubes were negative for STIC. All initial and deeper sections underwent consensus review by panel of experts in gynecologic pathology. These cases are part of a larger study in which we had examined 300 consecutive bilateral salpingectomies using the SEE-FIM protocol and a single-H&E section per block and had identified 68 cases of pelvic serous carcinoma, of which 12 were associated with STIC. We calculated the sensitivity of a single-H&E section to detect STIC, as compared with examination of multiple deeper sections, and reevaluated the clinicopathologic data of the parent study in light of the additional cases of STIC. In the 56 cases initially negative for STIC, 4 cases of STIC were identified after examination of multiple deeper sections of the fallopian tubes. The single-H&E section SEE-FIM approach therefore detected only 75% (95% confidence interval, 51%-90%) of STIC that was present. Three of these new cases were associated with primary ovarian serous carcinoma and 1 with primary peritoneal serous carcinoma. All 3 new cases associated with ovarian carcinoma were noted in women without neoadjuvant chemotherapy. In considering the data from the parent study, we calculated a statistically significant lower incidence of STIC in women with ovarian serous carcinoma who received neoadjuvant chemotherapy as compared with those who did not (P=0.042). Our study demonstrated that additional cases of STIC can be detected if deeper sections are examined. These additional cases also highlighted a statistically significant difference in the incidence of STIC associated with ovarian serous carcinoma who received neoadjuvant chemotherapy relative to those who did not. Consideration to this should be given in future studies of the prevalence of STIC and to routine examination of salpingectomy specimens from women at high risk for pelvic serous carcinoma.

Hemispheric extra-ventricular glioneurocytoma: a clinicopathological review with detailed immunohistochemical profile.

Glioneuronal tumors have recently been recognized in the WHO Classification of Tumors of the Central Nervous System, 2007 [14]. However, the entities included in this category do not encompass all the glioneuronal tumors encountered during practice. We characterize a new entity called glioneurocytoma (GNC) showing distinct morphology with glial and neuronal differentiation. We reviewed 10 cases of glioneurocytomas diagnosed in our department during 2003 and 2004, with emphasis on clinicopathological features, immunohistochemical profile, genetic aberrations and prognosis. The cases included in the study showed equal gender distribution and age range of 23-40 years and mean age of 34.4 years at the time of initial presentation. Most of the tumors were centered in the frontal lobe. In our study, GFAP was the most sensitive and relatively specific marker for glial differentiation and remains the marker of choice for glial differentiation. CD56 and S100 protein were sensitive but non-specific. Vimentin, CD57 and NF were non-contributory in the immunohistochemical work up of glioneurocytomas. We concluded that the diagnosis of glioneurocytomas requires attention to morphological details and proper immunohistochemical assessment, using a panel of both glial and neuronal markers. Particular attention is recommended to the existence of the intermediate neurocytic cells which may be unique for these tumors. Future implication with full molecular analysis for gene expression profiling is suggested for proper and accurate identifying this entity.

Frequency of serous tubal intraepithelial carcinoma in various gynecologic malignancies: a study of 300 consecutive cases.

Serous tubal intraepithelial carcinoma (STIC) has been implicated in the pathogenesis of pelvic serous carcinoma. We hypothesized that, if this is the case, the frequency of STIC should be substantially lower in endometrial serous carcinomas, in nonserous gynecologic malignancies, and in benign gynecologic neoplasms than in ovarian or peritoneal serous carcinomas. From 2007 to 2009 the fallopian tubes of 342 consecutive gynecologic cases were entirely submitted for histology using the Sectioning and Extensively Examining the FIMbriated end protocol. This study included 300 of these cases (277 TAH-BSO, 23 BSO) after exclusion. The hematoxylin and eosin-stained slides from the fallopian tubes were independently reviewed by 2 gynecologic pathologists who were blinded to all other findings; disagreements were resolved by a third pathologist. Among 46 cases of ovarian malignancies, STIC was identified in 6 (18.8%) of 32 cases of serous carcinoma, but not in any other subtype. Similarly, STIC coexisted in 4 (14.3%) of 28 cases of endometrial serous carcinoma; however, no STIC was identified in any of the 74 cases of nonserous endometrial malignancies. STIC was identified in 2 (28.6%) of 7 cases of peritoneal serous carcinoma. No STIC was identified among 15 nongynecologic malignancies, 90 cases of benign conditions, and 27 cases of other conditions including 4 cases of cervical adenocarcinoma in situ and high-grade cervical intraepithelial lesions, 8 cases of endometrial atypical complex hyperplasias, and 15 cases of ovarian borderline tumors. In conclusion, the fallopian tube may be the origin of some pelvic serous carcinomas. Other possibilities that may explain the origin of pelvic high-grade serous carcinoma are discussed. Given that STIC coexisted with 14% of endometrial serous carcinomas, a more unifying theory may be that gynecologic serous carcinomas and STIC are multifocal lesions.

Squamous lesions of the ovary.

The ovary shows an innate potential for markedly variable histogenesis, including squamous differentiation. Although not uncommon, squamous differentiation in ovarian lesions can be present in several diagnostic contexts, both benign and malignant. We present a review of the literature pertaining to squamous lesions of the ovary. In particular, we summarize the relevant clinical features, workup, gross findings and histopathologic features, differential diagnosis, treatment, and prognostic features of both the common and rare squamous entities found in the ovary.

Lymphoproliferative Lesions in the Setting of HIV Infection: A Five-Year Retrospective Case Series and Review.

A wide variety of noninfectious lesions have been identified in association with HIV infection. Many hematolymphoid lesions are possible in this patient group, both reactive and neoplastic. Epidemiologic data suggests that lymphoid malignancies are among the most common neoplasms in patients with HIV. We present a selective case series assembled over a 5-year period from the relatively low HIV-prevalence Hamilton Regional Laboratory Medicine Program (HRLMP), a tertiary care referral centre in Southern Ontario. This series serves to demonstrate the wide variety of lymphoid lesions that may be encountered in patients with HIV. In addition to outlining the pathologic work-up necessary in these cases, we discuss characteristics that distinguish the HIV-associated lesions from the pathobiologically similar non-HIV-associated lymphoid lesions.

Primary anaplastic large cell lymphoma of the breast arising in reconstruction mammoplasty capsule of saline filled breast implant after radical mastectomy for breast cancer: an unusual case presentation.

BACKGROUND: Primary non-Hodgkin lymphoma (NHL) of the breast represents 0.04-0.5% of malignant lesions of the breast and accounts for 1.7-2.2% of extra-nodal NHL. Most primary cases are of B-cell phenotype and only rare cases are of T-cell phenotype. Anaplastic large cell lymphoma (ALCL) is a rare T-cell lymphoma typically seen in children and young adults with the breast being one of the least common locations. There are a total of eleven cases of primary ALCL of the breast described in the literature. Eight of these cases occurred in proximity to breast implants, four in relation to silicone breast implant and three in relation to saline filled breast implant with three out of the eight implant related cases having previous history of breast cancer treated surgically. Adjuvant postoperative chemotherapy is given in only one case. Secondary hematological malignancies after breast cancer chemotherapy have been reported in literature. However in contrast to acute myeloid leukemia (AML), the association between lymphoma and administration of chemotherapy has never been clearly demonstrated. CASE PRESENTATION: In this report we present a case of primary ALCL of the breast arising in reconstruction mammoplasty capsule of saline filled breast implant after radical mastectomy for infiltrating ductal carcinoma followed by postoperative chemotherapy twelve years ago. CONCLUSION: Primary ALK negative ALCL arising at the site of saline filled breast implant is rare. It is still unclear whether chemotherapy and breast implantation increases risk of secondary hematological malignancies significantly. However, it is important to be aware of these complications and need for careful pathologic examination of tissue removed for implant related complications to make the correct diagnosis for further patient management and treatment. It is important to be aware of this entity at this site as it can be easily misdiagnosed on histologic grounds and to exclude sarcomatoid carcinoma, malignant melanoma and pleomorphic sarcoma by an appropriate panel of immunostains to arrive at the correct diagnosis of ALCL.

Cytokeratin positivity in myxopapillary ependymoma--a potential diagnostic pitfall.

BACKGROUND: Myxopapillary ependymomas (MPE) occur in the filum terminale of the spinal cord, but also present in extra-spinal locations such as subcutaneous tissue and brain. They are slow growing grade I gliomas. Areas of solid growth pattern with aggregates of cells with "epithelioid morphology" seen in MPE can mimic metastatic carcinoma. The presence of occasional cells with clear cytoplasm and morphology can resemble Chordoma. Diagnosis can be missed due to these morphological similarities, which could affect patient management and hence, long term survival. CASE PRESENTATION: We describe two cases of MPE with cytokeratin (AE1 AE3, CAM 5.2, Cytokeratin 7 and cytokeratin 20) expression. CONCLUSION: MPE can be positive for Cytokeratins (CAM 5.2, AE1 AE3, CK7) and focally for EMA, which could be misdiagnosed as metastatic carcinoma. In cases demonstrating epithelioid and clear cell morphology, the diagnosis of MPE should be made in conjunction with histology, proper immunohistochemical profile which includes co-expression of GFAP, S-100 protein and epithelial markers, radiologic findings and site. It is important to be aware of the cytokeratin profile in MPE to avoid erroneous diagnosis with other tumour entities.