North American Journal of Medicine and Science
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Gastrointestinal Stromal Tumors: Clinicopathology and Advances in Molecular Pathogenesis
Get PDFGastrointestinal stromal tumors (GISTs) are common mesenchymal neoplasms in the gastrointestinal (GI) tract that need to be differentiated from other GI mesenchymal tumors. They often present with heterogeneous features based on the anatomic locations, histomorphology and gene mutation status, which may lead to diagnostic and treatment challenges. Over the past decade, numerous studies revealed that KIT and PDGFRα tyrosine kinase pathways play key roles in the molecular pathogenesis of GISTs. Subsequently, specific biomarkers, such as CD117 and DOG1, have been developed and greatly improved the diagnostic accuracy. Moreover, advances in understanding the molecular nature of GISTs also provide valuable therapeutic targets. Two tyrosine kinase inhibitors, Imatinib and Sunitinib, have currently been approved for treating patients with advanced and metastatic GISTs.
Cell Block Examination Is Critical for Sarcoidosis Diagnosis by Endobronchial Ultrasound-Guided Mediastinal Lymph Node Fine Needle Aspiration
Get PDFIntrathoracic sarcoidosis is often diagnosed by transbronchial lung parenchymal biopsy (TBBx), however, recent studies suggest endobronchial ultrasound-guided transbronchial fine needle aspiration of mediastinal lymph node (EBUS-FNA) is safer with superior diagnostic yield. We report our experience from 2008 to 2010 with combined EBUS-FNA and TBBx in 61 consecutive patients with clinical suspicion of sarcoidosis. One to three mediastinal lymph nodes (LN) in various locations were sampled using 21/22-gauge needles with on-site interpretation. Additional one to two specimens per site were collected in Normosol® for cell block preparations. A definitive diagnosis of sarcoidosis was made in 51 patients (84%) by EBUS-FNA/TBBx studies (46) and clinical information (5); alternative diagnoses were established in 8 patients (13 %); the last 2 patients remained suspicious for sarcoidosis without confirmatory tissue diagnosis. Of the 46 biopsy (EBUS-FNA and/or TBBx) confirmed cases, 37 (80.0%) were diagnosed by EBUS-FNA. Cell blocks prepared from all 37 patients contained diagnostic material, 10 (27.0%) were interpreted as such by on-site evaluations. The diagnostic yield of LNs at different locations varied, being 100, 68, 50 and 20% in R12, subcarinal, R4, and R11, respectively. A total of 36 patients had both EBUS-FNA and TBBx performed during the same visit. Diagnoses were identical in 15 patients (42 %). TBBx independently identified 9 cases of sarcoidosis. This study indicates that cell block preparation is valuable for EBUS-FNA diagnosis of sarcoidosis. EBUS-FNA and TBBx are effective and complimentary tools for intrathoracic sarcoidosis diagnosis.[N A J Med Sci. 2012;5(4):198-202.
Diagnosing Hypocellular Collagenized Spindle Cell Squamous Carcinoma of the Head and Neck: A Rare Subtype with Misleading Histologic Features
Get PDFSpindle cell squamous carcinoma of the head and neck (SCSCHN) is a high-grade variant of squamous cell carcinoma (SCC) that is histologically characterized by the presence of a conventional SCC and an associated malignant spindle cell stromal component. Typically, the spindle cell infiltrate expresses epithelial markers such as cytokeratin and is hypercellular and pleomorphic and readily identifiable as malignant. However, the stromal component in the hypocellular collagenized variant of SCSC is very hypocellular with prominent collagenization. In addition, cytokeratin immunoreactivity can be absent in up to 40% of cases of SCSC, and the conventional SCC component may be absent. These features create diagnostic challenges, and literatures addressing these issues are lacking. We describe the clinical, pathologic and immunohistochemical features of three cases of hypocellular collagenized SCSCHN and discuss major differential diagnoses that will allow for its proper identification.
Pathology Imaging Informatics for Clinical Practice and Investigative and Translational Research
Get PDFPathologists routinely interpret gross and microscopic specimens to render diagnoses and to engage in a broad spectrum of investigative research. Multiple studies have demonstrated that imaging technologies have progressed to a level at which properly digitized specimens provide sufficient quality comparable to the traditional glass slides examinations. Continued advancements in this area will have a profound impact on the manner in which pathology is conducted from this point on. Several leading institutions have already undertaken ambitious projects directed toward digitally imaging, archiving, and sharing pathology specimens. As a result of these advances, the use of informatics in diagnostic and investigative pathology applications is expanding rapidly. In addition, the advent of novel technologies such as multispectral imaging makes it possible to visualize and analyze imaged specimens using multiple wavelengths simultaneously. As these powerful technologies become increasingly accepted and adopted, the opportunities for gaining new insight into the underlying mechanisms of diseases as well as the potential for discriminating among subtypes of pathologies are growing accordingly.
Magnetic Resonance Spectroscopy of Adult Thalamic Glioblastoma Multiforme
Get PDFThalamic glioblastoma multiforme (GBM) is a rare malignant primary central nervous system (CNS) tumor. Here we report a case of adult unilateral GBM involving the right thalamus. The diagnosis of GBM was first indicated by a region of irregular enhancement with central necrosis in the thalamus, visualized with traditional magnetic resonance imaging (MRI) with contrast. Magnetic resonance spectroscopy (MRS), showing elevated lipid and lactate peaks, provided further evidence of GBM while rendering primary CNS lymphoma (PCNSL), anaplastic glioma, or metastasis less likely. The final diagnosis of GBM was confirmed by pathological examination of the tumor specimen. This report highlights the utility of combining MRS with other imaging modalities to facilitate the diagnosis of CNS lesions
Fatal Mycoplasma Pneumoniae Infection: Case Report and Review of the Literature
Get PDFMycoplasma pneumoniae (M. pneumoniae) infection is rarely fatal in young adults. Most patients have no symptoms or mild nonspecific symptoms or signs with infection. Up to 3-10% infected people may develop pneumonia. We herein report a fatal case of M. pneumoniae infection presenting with acute respiratory failure and brain death in a 27 year old female. Autopsy revealed that diffuse alveolar damage in the lungs and acute hemorrhagic leukoencephalopathy (AHLE), a hyperacute form of acute disseminated encephalomyelitis (ADEM) in the brain.
Clear Cell Papillary Renal Cell Carcinoma – A New Emerging Entity
Get PDFClear cell papillary renal cell carcinoma was initially reported in patients with end stage renal disease under name of “end stage renal disease-associated renal cell carcinoma”. However, subsequent studies show that the tumor is also seen in non-end stage settings with or without impaired renal function. Recent advances in molecular genetic techniques and immunohistochemical staining have showed that clear cell papillary renal cell carcinoma is a new distinct entity that has unique genetic, histomorphological and clinical characteristics. This review summarizes the most current views on clear cell papillary renal cell carcinoma with focus on histomorphological features, immunohistochemical profiles and molecular genetic characteristic of this new entity
Morphological Variants of Ameloblastoma and Their Mimickers
Get PDFAmeloblastoma is the second most common intraosseous benign odontogenic tumor. This tumor exhibits a locally aggressive behavior. A number of morphological variants of ameloblastoma have been documented in the literature and at times, may pose a diagnostic challenge to the pathologist. The purpose of this paper is to discuss the spectrum of histopathological variants of ameloblastoma. Recognition of the subtypes of ameloblastoma is important, as it has been documented that some subtypes may exhibit a more aggressive biological behavior than the so-called “conventional” ameloblastoma.
Novel Chromosomal Aberration as Evidence of Clonal Evolution in a Case of Relapsed Acute Myeloid Leukemia
Get PDFAcute myeloid leukemia (AML) is a heterogeneous group of diseases with a multitude of molecular genetic aberrations and variable clinical outcome. Clonal chromosomal abnormalities have been identified in over 50% of AML cases, and have been regarded as one of the most important prognostic markers. We present a case of a 28-year-old Caucasian woman with AML without maturation, diploid karyotype, that was resistant to multiple chemotherapies and relapsed after matched unrelated stem cell transplantation. Conventional cytogenetic analysis performed on bone marrow specimens revealed 46,XX,t(2;16)(p21;p11.2),t(11;14)(p13;p11.2). The t(11;14)(p13;p11.2) was confirmed by fluorescence in situ hybridization using a whole chromosome paint probe for chromosome 11. Morphologically, the bone marrow was hypercellular with trilineage hypoplasia and 84% blasts. Flow cytometry analysis showed that the blasts were of myeloid immunophenotype. Molecular studies detected internal tandem duplication of the FLT3 gene and a mutation in exon 12 of the NPM1 gene. The patient then received monotherapy with AC220, achieved a brief remission, and died of relapsed disease 23 months after initial diagnosis. This
Elastotic Changes in the Gastrointestinal Tract: A Review of Literature
Get PDFElastotic changes are benign lesions in the gastrointestinal tract that often appear as polyps and show histologically a remarkable increase in elastic fibers. Because of their hyaline and amorphous appearance in hematoxylin and eosin (H&E) stained slides, elastotic changes often resemble amyloidosis. However, they are negative in Congo red staining. Reviewing the literature we found 35 cases in 12 publications in the English and French literature since 1985. The results indicate that the patients’ age ranged from 24 to 88 years (mean 58.2, median 58) and presented a balanced gender ratio (M/F = 17/18). Usually the lesions presented as polyps or irregular mucosal areas. Mostly, they were found during endoscopic examination in the colon or rectum (16 cases), while six cases were located in the stomach and only two in the small bowel. Some authors consider the alterations to be a reactive process, e.g. within (gastric) ulcers, whereas others speculate about a connection with systemic diseases of the connective tissue (Ehlers-Danlos Syndrome, Pseudoxanthoma elasticum). Based on our observations we distinguished angioelastosis, showing a relation to submucosal vessels, as a separate entity from gastrointestinal elastofibroma, that presents the same histologic morphology as Elastofibroma dorsi. Conclusion: Elastofibromatous changes in the gastrointestinal tract are quite common benign findings and should be considered as a possible differential diagnosis in examining gastrointestinal specimens