Potential pitfalls of needle tract effects on repeat thyroid fine-needle aspiration.

BACKGROUND: Fine-needle aspiration (FNA) is a screening and diagnostic tool used in the evaluation of thyroid nodules. Its use has resulted in an increase in the ratio of malignant versus benign thyroid nodules undergoing surgical excision. However, the FNA procedure produces some histological and cytologic alterations, which may lead to misinterpretation on repeat FNA. The goal of the current study was to characterize FNA-induced morphological alterations and their potential influence on interpretations in repeat FNA specimens. METHOD: Thyroidectomy specimens that had benign histological diagnoses and for which previous FNA specimens were available were retrieved. The FNA-induced histological alterations were evaluated and grouped based on the interval between the FNA procedure and surgical excision. Repeat thyroid FNA specimens with a cytologic diagnosis of "atypical cells/follicular lesion" were reviewed. Worrisome cytologic features that might occur after the previous FNA procedure were discussed. RESULTS: Needle tracts were identified in 68 of the 96 thyroidectomy specimens studied. FNA-induced histological alterations included hemorrhage, granulation, exuberant fibroblastic reaction, reactive follicular cells, infarction, and scarring. The presence of plump endothelial cells, myofibroblasts, and, particularly, reactive follicular cells with nuclear grooving and nuclear clearing are potential pitfalls in repeat FNA and these changes are reported to peak within 20 to 40 days after the FNA procedure. Sixteen of 152 repeat FNA cases were diagnosed as atypical cells/follicular lesion, and FNA-induced changes might have contributed to the diagnosis in 2 of these 16 cases. CONCLUSIONS: Cytologists should be aware of atypical cellular changes caused by previous FNA procedures. Although uncommon, these changes may become potential pitfalls in the cytologic diagnosis of repeat thyroid FNA specimens.

Telecytopathology for immediate evaluation of fine-needle aspiration specimens.

BACKGROUND: On-site evaluation of fine-needle aspiration (FNA) specimens by a pathologist is essential to obtain adequate samples and provide a preliminary diagnosis. Distance from the laboratory can make this difficult. The authors present their experience with on-site evaluation using telecytopathology. METHODS: Dynamic images of cytology smears were captured and processed with a Nikon digital camera system for microscopy and transmitted via Ethernet. A pathologist accessed the real-time images on a computer and interpreted them while communicating with on-site operators over the telephone. Sample adequacy and accuracy of preliminary diagnosis were compared with those obtained by regular on-site evaluation. RESULTS: A total of 429 telecytopathology cases and 363 conventional on-site cases were compared. Specimens were mainly from the pancreas, gastrointestinal tract, liver, and lymph nodes. Adequacy rate was 94.0% for telecytopathology and 97.7% for conventional cases. Preliminary diagnoses of unsatisfactory, adequate (defer), negative/benign, atypical, neoplasm, suspicious, and positive for malignancy were 6.3%, 13.5%, 14.9%, 17.9%, 7.2%, 8.6%, and 31.5% for telecytopathology and 3.9%, 30.6%, 21.5%, 9.6%, 5.0%, 5.2%, and 24.2% for conventional cases. Preliminary and final diagnoses were discrepant in 7 (1.8%) of 371 telecytopathology cases, and in 8 (3.1%) of 252 conventional cases. Difficulty was encountered in some cases in distinguishing pancreatic endocrine neoplasm from lymphoid proliferations, and low grade pancreatic tumors from chronic pancreatitis via telecytopathology. CONCLUSIONS: On-site evaluation of FNA specimens via telecytopathology assures sample adequacy and accurate preliminary diagnosis compared with the conventional method. It allows pathologists to use their time more efficiently and makes on-site evaluations at remote locations possible.

Cytomorphologic features of primary anaplastic large cell lymphoma of the psoas muscle: a case report and literature review.

Ki-1 (CD30) positive anaplastic large cell lymphoma (ALCL) is an uncommon malignancy, which may present with nodal as well as extra-nodal disease. Primary skeletal muscle Ki-1 (CD30) positive ALCL is an even rarer event with few cases reported in the literature and only some with published cytomorphologic features. An 83-year-old woman underwent a fine needle aspiration (FNA) of a psoas muscle mass. Smears demonstrated a predominantly discohesive population of large pleomorphic cells. The nuclei were hypechromatic and lobulated, with often multinucleation. Nucleoli were prominent in a subset of cells. Cytoplasmic vacuolization was also present. No lymphoglandular bodies were identified. A cytodiagnosis of malignant cells favoring metastatic melanoma vs. poorly differentiated carcinoma was rendered. Morphologic and immunohistochemical features later revealed a primary psoas muscle Ki-1 (CD30) positive ALCL with negative staining for anaplastic large cell lymphoma kinase (ALK). Cytologic features of ALCL mimic epithelial neoplasms, sarcomas, melanoma and other lymphomas. Although rare, ALCL should be a diagnostic consideration when discohesive pleomorphic malignant cells are encountered on FNA of a muscle neoplasm.

Columnar cell lesions and pseudoangiomatous hyperplasia like stroma: is there an epithelial-stromal interaction?

The significance of association between cancer and its microenvironment has been increasingly recognized. It has been shown in animal models that interaction between neoplastic epithelial cells and adjacent stroma can modulate tumor behavior. Carcinoma associated stromal cells can transform normal epithelial cells into neoplastic cells. In breast, columnar cell lesions are non-obligate precursors of low grade ductal carcinoma in situ. Columnar cell lesions can be seen intimately associated with PASH-like-stroma, a lesion we termed as CCPLS. Our aim is to investigate epithelial-stromal interactions in CCPLS and compare them to PASH without columnar cell lesions in breast core needle biopsies. Normal terminal duct lobular unit (TDLU) epithelium was seen in association with columnar cell lesions as well as PASH. Eight (8) cases of each category were examined by a panel of immunostains: CD117 (C-kit), CD34, CD105, bFGF, AR, ER-beta, MIB-1. We observed a markedly decreased expression of c-kit in columnar cell lesions compared to TDLU-epithelium. CD105 showed a quantitative increase in activated vessels in CCPLS compared to PASH. A subset of CCPLS and PASH were androgen receptor positive. A strong nuclear positivity for ER-beta is observed in the epithelium and stroma of all CCPLS cases. We conclude that (1) activated blood vessels predominate in CCPLS; (2) A molecular alteration is signified by c-kit loss in columnar cell lesions; (3) ER-beta and androgen receptor positivity indicate CCPLS are hormonally responsive lesions. Our study suggests an intimate vascular and hormone dependent epithelial-stromal interaction exists in CCPLS lesions.

Utility of a dual immunostain cocktail comprising of p53 and CK20 to aid in the diagnosis of non-neoplastic and neoplastic bladder biopsies.

BACKGROUND: Distinction between non-neoplastic and neoplastic bladder lesions is therapeutically and prognostically important. Our objective is to describe the use of double immunohistochemistry (DIHC) for p53+CK20 as a tool for diagnosing neoplasia in bladder biopsies. METHODS: p53+CK20 DIHC were examined in 38 reactive atypia, 10 dysplasia, 9 carcinoma in situ (CIS) and 7 invasive carcinoma (IC) cases. CK20 was evaluated according to distribution extent and degree of intensity whereas percentage of positive cells together with staining intensity was taken into account in the evaluation of p53. RESULTS: 92% of reactive cases were either CK20(-) or (+) only in the upper 1/3 urothelium. In dysplastic cases CK20 staining distribution was as follows: 60% in 2/3 of the urothelium, 30% full thickness, 10% in the upper 1/3 urothelium. Among CIS cases, 89% had full thickness CK20 positivity, of which 62% were p53(+). 71% of IC cases exhibited strong and full thickness dual staining. CONCLUSION: This is the first study in the literature to use DIHC of p53+CK20 in distinction of non-neoplastic and neoplastic bladder lesions. Dual staining by p53+CK20 cocktail allows for histologic correlation and diminishes the risk of losing the area of interest in limited biopsy specimens.

[Microscopic colitis: pathogenesis]. / Colítis microscópica: patogénesis.

INTRODUCTION: Microscopic colitis (MC) is a chronic inflammatory process observed in colon biopsies of patients with chronic aqueous diarrhea. It is called microscopic because diagnosis is determined by histological studies since the microscopic characteristics of the colon endoscopy are normal. Two patterns exist: Lymphocytic Microscopic Colitis and Collagenous Microscopic Colitis. Etiology is unknown, and the proposed pathogenic mechanisms indicate an immunological phenomenon. Based on this, the authors of this study hypothesize that lymphocytic infiltration of the lamina propria could be related to cytotoxic lymphocytes CD8 as causative agents of colon tissue damage. OBJECTIVES: Prove hypothesis of immunological pathogenesis of MC. APPARATUS AND METHODS: Thirty eight (38) patients with diagnosed MC were recruited for the last four years in the Pathology Laboratory at Ricardo Palma University. Twenty two (22) colon biopsies with the most severe histological lesions were selected. These biopsies were obtained from 17 patients: 5 patients had 2 biopsies in 2 colonoscopy sessions. Biopsies were fixed in neutral formaldehyde, processed through the paraffin inclusion method, and stained with hematoxiline-eosine and Masson trichromic to distinguish collagenous tissue. Immunohistochemistry was conducted in 4- or 5-micron-thick histological sections processed through the immunoperoxidase method. RESULTS: Nineteen (19) biopsies corresponded to Lymphocytic MC and 3 to Collagenous MC. Lymphocytic MC showed intraepithelial lymphocytosis, dystrophic epithelial damage in the areas of lymphocytic infiltration, lamina propria inflammation with lymphocytes and plasma cells, and normal basement membrane. Collagenous MC showed thickened basement membrane due to the presence of a collagenous band, mild to moderate intraepithelial lymphocytosis, vacuolization,and frequent detachment of protective epithelium. Twenty two (22) biopsies were positive in the immunohistochemical studies.

Colitis microscópica: Patogénesis / Microscopic colitis: Pathogenesis

Introducción: Colitis microscópica (CM) es el proceso inflamatorio crónico observado en biopsias del colon de pacientes con diarrea crónica acuosa. Se denomina microscópica porque el diagnóstico es histológico ya que las características microscópicas de la endoscopía del colon son normales. Incluye 2 patrones: Colitis microscópica Linfocítica y la Colítis microscópica Colagenosa. La causa es desconocida y los mecanismos patógenos propuestos señalan un fenómeno inmunológico; de acuerdo a este concepto los autores del presente estudio suponemos que la infiltración linfocítica en la lámina propia podrían corresponder a linfocitos citotóxicos CD8 como ejecutores del daño tisular colónico. Objetivos: Probar la hipótesis de la patogénesis inmunológica de la CM. Material y Método: 38 pacientes con diagnóstico de CM reclutados durante los 4 últimos años en el laboratorio de patología Clínica Ricardo Palma. Se seleccionaron 22 biopsias de colon con lesiones histológicas más severas, correspondientes a 17 pacientes, 5 de ellos tuvieron 2 biopsias en 2 sesiones colonoscópicas, las biopsias fueron fijadas en formol neutro. Y procesadas por el método de inclusión en parafina, tenidas con hematoxilina y eosina y tricrómica de Masson para tejido colágeno. La inmunohistoquímica se hizo en secciones histológicas de 4 y 5 micras de espesor precesadas por el método de la Inmunopereoxidasa. Resultados: 19 biopsias correspondieron a CM Linfocítica y 3 a CM Colagenosa. El CM Linfocítica mostró linfocitosis intraepitelial, daño epitelial distrófico en las áreas de infiltración linfocítica, inflamación de la lámina propia con linfocitos y célula plasmática, membrana basal normal. La CM Colagenosa mostró membrana basal engrosada por la presencia de una banda colágena, linfocitos Intra epiteal leve a moderado vacuolización y frecuente desprendimiento del epitelio cobertor. Los estudios de Inmunohistoquímica fueron positivos en las 22 biopsias estudiadas.

Introduction: Microscopic colitis (MC) is a chronic inflammatory process observed in colon biopsies of patients with chronic aqueous diarrhea. It is called microscopic because diagnosis is determined by histological studies since the microscopic characteristics of the colon endoscopy are normal. Two patterns exist: Lymphocytic Microscopic Colitis and Collagenous Microscopic Colitis. Etiology is unknown, and the proposed pathogenic mechanisms indicate an immunological phenomenon. Based on this, the authors of this study hypothesize that lymphocytic infiltration of the lamina propria could be related to cytotoxic lymphocytes CD8 as causative agents of colon tissue damage. OBJECTIVES: Prove hypothesis of immunological pathogenesis of MC. Apparatus and Methods: Thirty eight (38) patients with diagnosed MC were recruited for the last four years in the Pathology Laboratory at Ricardo Palma University. Twenty two (22) colon biopsies with the most severe histological lesions were selected. Thesebiopsies were obtained from 17 patients: 5 patients had 2 biopsies in 2 colonoscopy sessions. Biopsies were fixed in neutral formaldehyde, processed through the paraffin inclusion method, and stained with hematoxiline-eosine and Masson trichromic to distinguish collagenous tissue. Immunohistochemistry was conducted in 4- or 5-micron-thick histological sectionsprocessed through the immunoperoxidase method. RESULTS: Nineteen (19) biopsies corresponded to Lymphocytic MC and 3 to Collagenous MC. Lymphocytic MC showed intraepithelial lymphocytosis, dystrophic epithelial damage in the areas of lymphocytic infiltration, lamina propria inflammation with lymphocytesand plasma cells, and normal basement membrane. Collagenous MC showed thickened basement membrane due to the presence of a collagenous band, mild to moderate intraepithelial lymphocytosis, vacuolization, and frequent detachment of protective epithelium. Twenty two (22) biopsies were positive in the immunohistochemical...

Lipomatous hypertrophy of the interatrial septum: an overview.

Lipomatous hypertrophy of the interatrial septum is a rare, but increasingly recognized, anomalous developmental or neoplastic lesion of the heart. This entity was first described in 1964 at autopsy and is identified before death based on its distinctive characteristics on echocardiography, computed tomography, and magnetic resonance imaging. Although it is often asymptomatic, the mass has been associated with supraventricular arrhythmias and sudden death. In rare patients who experience intractable symptoms, surgical excision of the lesion may provide relief. Therefore, lipomatous hypertrophy of the interatrial septum is of interest to the pathologist when a cardiac mass is received for evaluation or at autopsy when a patient has experienced sudden death from an unknown cause.