Lydia Contis

Validating Whole Slide Imaging for Diagnostic Purposes in Pathology: Guideline from the College of American Pathologists Pathology and Laboratory Quality Center

CONTEXT There is increasing interest in using whole slide imaging (WSI) for diagnostic purposes (primary and/or consultation). An important consideration is whether WSI can safely replace conventional light microscopy as the method by which pathologists review histologic sections, cytology slides, and/or hematology slides to render diagnoses. Validation of WSI is crucial to ensure that diagnostic performance based on digitized slides is at least equivalent to that of glass slides and light microscopy. Currently, there are no standard guidelines regarding validation of WSI for diagnostic use. OBJECTIVE To recommend validation requirements for WSI systems to be used for diagnostic purposes. DESIGN The College of American Pathologists Pathology and Laboratory Quality Center convened a nonvendor panel from North America with expertise in digital pathology to develop these validation recommendations. A literature review was performed in which 767 international publications that met search term requirements were identified. Studies outside the scope of this effort and those related solely to technical elements, education, and image analysis were excluded. A total of 27 publications were graded and underwent data extraction for evidence evaluation. Recommendations were derived from the strength of evidence determined from 23 of these published studies, open comment feedback, and expert panel consensus. RESULTS Twelve guideline statements were established to help pathology laboratories validate their own WSI systems intended for clinical use. Validation of the entire WSI system, involving pathologists trained to use the system, should be performed in a manner that emulates the laboratorys actual clinical environment. It is recommended that such a validation study include at least 60 routine cases per application, comparing intraobserver diagnostic concordance between digitized and glass slides viewed at least 2 weeks apart. It is important that the validation process confirm that all material present on a glass slide to be scanned is included in the digital image. CONCLUSIONS Validation should demonstrate that the WSI system under review produces acceptable digital slides for diagnostic interpretation. The intention of validating WSI systems is to permit the clinical use of this technology in a manner that does not compromise patient care.

Salivary duct carcinoma

Salivary duct carcinoma (SDC) is a highly malignant tumor that is histologically similar to ductal carcinoma of the breast. This article presents the clinicopathologic features of 15 patients with SDC arising in the salivary glands. The majority of patients were male and aged 65 years or older. The tumor was most often located in the parotid gland. Pain, facial palsy, and presence of calcification in the CT scan were diagnostic features suggestive of SDC. Histologically, 27% of the tumors arose from pre-existing pleomorphic adenoma. Perineural and lymphatic invasion were common findings. There was an extensive cervical lymph node involvement (73%). Distant metastasis was the most common cause of failure. Although SDC exhibits an unpredictable clinical course, total parotidectomy with neck dissection and adjunctive radiation therapy appear to be appropriate for local and regional control of this aggressive neoplasm.

Basaloid squamous cell carcinoma of the head and neck: A clinicopathologic and flow cytometric study of 10 new cases with review of the English literature

INTRODUCTION We describe the clinicopathologic and flow cytometric features of 10 cases of basaloid squamous cell carcinoma (BSCC) of the head and neck to determine if DNA ploidy is a useful prognostic indicator. We also provide a review of 80 cases previously reported in the English language literature. MATERIALS AND METHODS The 10 cases were obtained from the surgical pathology files of Presbyterian University Hospital and The Eye and Ear Institute, Pittsburgh, PA (1987-1991). In all 10 cases, the microscopic slides and clinical data were reviewed. Flow cytometry was performed using the Hedley technique and formalin-fixed, paraffin-embedded tissue. RESULTS The mean age of patients with BSCC was 64 years (range, 49 to 75 years). Tumor involved the base of tongue (n = 5), hypopharynx-epiglottis (n = 3), and tonsil (n = 1). One case presented with cervical lymph node metastasis from an unknown primary site. Histologically, BSCC showed a biphasic pattern with basaloid-squamous elements, comedonecrosis, stromal hyalinization, surface dysplasia, and an in situ and/or invasive squamous cell carcinoma component. Flow cytometry revealed six diploid and four aneuploid tumors. Five of six patients with diploid and all four patients with aneuploid tumors developed early regional and/or distant metastases. Of the two patients who died of disease, one had a diploid and the other an aneuploid tumor. CONCLUSION Our study reaffirms the predilection of BSCC for the base of tongue, pyriform sinus, and supraglottic larynx, and its aggressive biologic behavior with a high incidence of cervical lymph node metastasis (64%), distant spread (44%), and death from disease (38% mortality at 17 months median follow-up). However, in contrast to previous reports, tumor ploidy by flow cytometry provided no additional prognostic information beyond that supplied by routine histologic evaluation.

Salivary duct carcinoma: Part II. Immunohistochemical evaluation of 13 cases for estrogen and progesterone receptors, cathepsin D, and c-erbB-2 protein

Salivary duct carcinoma is an infrequent highly aggressive salivary gland tumor that is histologically similar to ductal carcinoma of the breast. We studied 13 cases by immunohistochemistry for the presence of estrogen and progesterone receptors, cathepsin D, and c-erbB-2 protein to determine whether the similarity to breast carcinoma extended beyond the light microscope to the molecular level and, if so, whether these markers might have therapeutic or prognostic value. Twelve of 13 cases contained sufficient amounts of tumor tissue for evaluation. Of these 12 cases, one (8%) was positive for estrogen receptors, none was positive for progesterone receptors, five (42%) were positive for cathepsin D, and three (25%) were positive for c-erbB-2 protein. Expression of cathepsin D and c-erbB-2 protein does not appear to have prognostic significance in salivary duct carcinoma. The 8% incidence of immunopositivity for estrogen receptors and absence of progesterone receptors in salivary duct carcinoma is considerably less than that seen in breast cancer. Nevertheless, because the occurrence of systemic metastasis in salivary duct carcinoma is such an ominous development largely unresponsive to chemotherapy, antihormonal therapy, such as used in breast cancer, might be considered on a trial basis for those tumors that are estrogen receptor-positive when conventional therapeutic modalities fail.

Experience with multimodality telepathology at the University of Pittsburgh Medical Center

Several modes of telepathology exist including static (store-and-forward), dynamic (live video streaming or robotic microscopy), and hybrid technology involving whole slide imaging (WSI). Telepathology has been employed at the University of Pittsburgh Medical Center (UPMC) for over a decade at local, national, and international sites. All modes of telepathology have been successfully utilized to exploit our institutions subspecialty expertise and to compete for pathology services. This article discusses the experience garnered at UPMC with each of these teleconsultation methods. Static and WSI telepathology systems have been utilized for many years in transplant pathology using a private network and client-server architecture. Only minor clinically significant differences of opinion were documented. In hematopathology, the CellaVision® system is used to transmit, via email, static images of blood cells in peripheral blood smears for remote interpretation. While live video streaming has remained the mode of choice for providing immediate adequacy assessment of cytology specimens by telecytology, other methods such as robotic microscopy have been validated and shown to be effective. Robotic telepathology has been extensively used to remotely interpret intra-operative neuropathology consultations (frozen sections). Adoption of newer technology and increased pathologist experience has improved accuracy and deferral rates in teleneuropathology. A digital pathology consultation portal (https://pathconsult.upmc.com/) was recently created at our institution to facilitate digital pathology second opinion consults, especially for WSI. The success of this web-based tool is the ability to handle vendor agnostic, large image files of digitized slides, and ongoing user-friendly customization for clients and teleconsultants. It is evident that the practice of telepathology at our institution has evolved in concert with advances in technology and user experience. Early and continued adoption of telepathology has promoted additional digital pathology resources that are now being leveraged for other clinical, educational, and research purposes.

Near-tetraploidy in adult acute myelogenous leukemia

Tetraploidy and near-tetraploidy are observed infrequently in hematologic malignancies, most commonly seen in cases of childhood acute lymphoblastic leukemia, and are associated with large blast size. Four cases of adult acute myelogenous leukemia (AML) with tetraploid or near-tetra-ploid karyotypes are reported, along with review of the related literature. AML subtypes included M1, M1, M4, and M5b. Tetraploidy was determined cytogenetically and confirmed by image cytometry (DNA index 2.0). The subjective impression of large blast size was confirmed by image cytometry, demonstrating mean blast nuclear areas of 237, 177, 203, and 216 microns2, (mean 208 microns2) in the cases with tetraploidy, compared to a mean of 134 microns2 in 10 control cases of AML with diploid or near diploid chromosome patterns. The clinical course was variable in the four cases reported. When compared with previously published cases, the occurrence of tetraploidy or near-tetraploidy in adult AML, unlike childhood ALL, does not appear to define a distinct subgroup in terms of FAB classification or to carry prognostic implications.

Experience with CellaVision DM96 for peripheral blood differentials in a large multi-center academic hospital system

Context and Aims: Rapid, accurate peripheral blood differentials are essential to maintain standards of patient care. CellaVision DM96 (CellaVision AB, Lund, Sweden) (CV) is an automated digital morphology and informatics system used to locate, pre-classify, store and transmit images of platelets, red and white blood cells to a trained technologist who confirms or edits CV cell classification. We assessed our experience with CV by evaluating sensitivity, specificity, positive predictive value and negative predictive value for CV in three different patient populations. Materials and Methods: We analyzed classification accuracy of CV for white blood cells, erythroblasts, platelets and artefacts over six months for three different university hospitals using CV. Results: CV classified 211,218 events for the adult cancer center; 51,699 events for the adult general hospital; and 8,009 events for the children′s hospital with accuracy of CV being 93%, 87.3% and 95.4% respectively. Sensitivity and positive predictive value were <80% for immature granulocytes (band neutrophil, promyelocyte, myelocyte and metamyelocytes) (differences usually within one stage of maturation). Cell types comprising a lower frequency of the total events, including blasts, showed lower accuracy at some sites. Conclusions: The reduced immature granulocyte classification accuracy may be due in part to the subjectivity in classification of these cells, length of experience with the system and individual expertise of the technologist. Cells with low sensitivity and positive predictive value comprised a minority of the cells and should not significantly affect the technologist re-classification time. CV serves as a clinically useful instrument in performance of peripheral blood differentials.

De novo acute myeloid leukemia with Philadelphia chromosome (BCR-ABL) and inversion 16 (CBFB-MYH11): report of two cases and review of the literature.

Cytogenetic and molecular studies play a major role in myeloid disease subclassification and risk stratification. The 2008 World Health Organization (WHO) classification [1] recognizes several diseasedefining recurrent genetic abnormalities in acute myeloid leukemia (AML), one of which is inversion 16(p13q22) or t(16;16), which fuses the CBFB gene to the MYH11 gene, and is characteristically associated with myelomonocytic differentiation, abnormal eosinophils, and a good prognosis [2]. The hallmark of chronic myelogenous leukemia (CML) is the Philadelphia chromosome (Ph), formed as a result of the BCR–ABL translocation; however, the BCR–ABL abnormality is not specific to CML and may also be seen in precursor lymphoid neoplasms and rare cases of de novo AML [3,4]. Coexistence of Ph(BCR–ABL1) and inv(16)(CBFB–MYH11) is extremely uncommon, with only 30 cases reported in the literature. The majority of these cases represent the blast phase of CML (CML-BP), and have shown an aggressive clinical course with rapidly progressive disease and resistance to chemotherapy [5,6]. In contrast, the few reports regarding de novo Phþ inv(16)þ AML have suggested a more favorable prognosis [6–14]. We report the clinicopathologic features of two new cases of de novo AML with the Philadelphia chromosome and inversion 16 and review the literature. Case one is a 30-year-old female who presented with leukocytosis (white blood cell count [WBC] 47.96 10/L) with circulating blasts (7%), monocytosis (54%), and thrombocytopenia (1146 10/L). The bone marrow was nearly 100% cellular and normal marrow elements were replaced by a prominent myelomonocytic infiltrate, with manual differential counts showing increased blasts (9%), monocytic cells (28%), and eosinophils (18%) with abnormal, basophilic granulation. Flow cytometric analysis confirmed increased CD14þ monocytic cells and an aberrant myeloblast population, which was CD347CD117þCD33þ. Classical cytogenetic studies showed the following complex karyotype: 46,XX, t(9;22;17;19)(q34; q11.2; q25; p13.1), inv(16) (p13q22)[19]. Quantitative real-time (RT)-polymerase chain reaction (PCR) studies performed on the peripheral blood and bone marrow confirmed the presence of a BCR–ABL fusion transcript at the minor breakpoint cluster region (p190). Therapy included hydroxyurea, allopurinol, imatinib (600 mg/day), and high dose chemotherapy with busulfan and cyclophosphamide, followed by an allogeneic stem cell transplant. Although a complete clinical, cytogenetic, and molecular remission was initially attained, the patient relapsed 29, 53, 70, and 80 months after the initial diagnosis. The first three relapses were responsive to cytarabine-based

Neurologic immune-related adverse events associated with adjuvant ipilimumab: report of two cases

BackgroundPD-1 and CTLA-4 inhibitors are associated with several adverse events including a spectrum of immune-related adverse effects (irAEs). Neurologic irAEs are uncommon occurrences with varied presentations. We describe two separate cases of ipilimumab associated meningoencephalomyelitis and demyelinating polyneuropathy with unusual presentations.Case presentationTwo melanoma patients were treated with ipilimumab in the adjuvant setting. The first patient developed a meningoencephalitis following 3 doses of ipilimumab. MRI imaging of the brain confirmed leptomeningeal enhancement although cerebrospinal fluid (CSF) analyses were negative for malignant cells consistent with meningoencephalomyelitis. Although she initially improved following treatment with steroids and intravenous immunoglobulin, she subsequently relapsed. She was successfully treated with infliximab and made a complete neurological recovery. A second patient developed progressive lower extremity weakness following two doses of ipilimumab. MRI imaging of the spine confirmed diffuse nerve root enhancement consistent with acute inflammatory demyelinating polyneuropathy (AIDP). He was treated with high dose steroids with resolution of neurological symptoms. Both patients remain disease free.ConclusionsNeurological irAEs are uncommon adverse events in the context of CTLA-4 and/or PD-1 inhibitor therapy. Care must be taken to distinguish these from leptomeningeal disease. Early recognition of neurological irAEs is critical for the initiation of specific anti-inflammatory agents to prevent and potentially reverse neurological sequelae.