AN UPDATE IN IMMUNOHISTOCHEMISTRY (PART I and II)

This 2-part special issue features 14 review articles with an attempt to cover IHC automation, standardization of diagnostic IHC, and the role of IHC in diagnosing tumors in major organs and tumors of unknown primary. This series begins with an article emphasizing standardization of diagnostic IHC in the preanalytic, analytic, and postanalytic phases, with a specific focus on (1) newly proposed guidelines on antibody validation from the College of American Pathologists Pathology and Laboratory Quality Center, (2) testing/optimizing a new antibody and troubleshooting, (3) interpreting and reporting IHC assay results, (4) continuing quality improvement programs, and (5) developing and implementing the concept of best practices in IHC.

from Fan Lin (2014) Evolving Practices of Diagnostic Immunohistochemistry. Archives of Pathology & Laboratory Medicine: December 2014, Vol. 138, No. 12, pp. 1561-1563.

PART I

Standardization of Diagnostic Immunohistochemistry: Literature Review and Geisinger Experience

Overview of Automated Immunohistochemistry

Immunohistochemistry in Undifferentiated Neoplasm/Tumor of Uncertain Origin

Utility of Immunohistochemistry in the Diagnosis of Pleuropulmonary and Mediastinal Cancers: A Review and Update

Application of Immunohistochemistry in Breast Pathology: A Review and Update

The Application of Immunohistochemical Biomarkers in Urologic Surgical Pathology

New Immunohistochemistry for B-Cell Lymphoma and Hodgkin Lymphoma

PART II

Application of Immunohistochemistry in Gastrointestinal and Liver Neoplasms: New Markers and Evolving Practice

Utility of Immunohistochemistry in the Pancreatobiliary Tract

The Utility of Immunohistochemistry in the Differential Diagnosis of Gynecologic Disorders

Review and Updates of Immunohistochemistry in Selected Salivary Gland and Head and Neck Tumors

Application of Immunohistochemistry in Thyroid Pathology

Immunohistochemistry in Dermatopathology

An Update on the Application of Newly Described Immunohistochemical Markers in Soft Tissue Pathology

Lepidic, a Canadian Neologism

In the new classification of adenocarcinomas, the term lepidic is defined as tumor cells proliferating along the surface of intact alveolar walls without stromal or vascular invasion.

[...] This word is a neologism, a new word invented in Canada in the early 1900s [by] John George Adami, MD. [...] After studying in Manchester, Cambridge, Breslau, and Paris, Dr Adami arrived at McGill University in Montreal, Canada, in 1892. Adami was a prolific writer, and he first used the term lepidic in an address to the Toronto Pathological Society on January 4, 1902. In his lecture titled ‘‘Original Communication on the Classification of Tumors,’’ he proposed 2 new terms that would be used to classify all neoplasms. The term lepidic (from greek meaning a rind, skin, or membrane) was applied to tumors that appeared to be derived from surface-lining cells. The term hylic (from greek meaning crude undifferentiated material) was applied to tumors that appeared to be derived from connective tissues. [...]

[...] The terms lepidic and hylic underwent a subtle change in meaning. In Herbert Spencer’s Pathology of the Lung,6 published in 1962, he stated that tumors may grow into the surrounding alveoli ‘‘either filling them with a solid mass of malignant cells (a hilic [sic] growth) or lining their walls (a lepidic growth).’’ This is a minor alteration in definition; however, this is where the modern definition of tumor growth along intact alveolar septa arose. [...]

In the early 1990s the erroneous belief that the term lepidic came from the etymologic origin ‘‘butterfly’’ became prevalent. [...] Soon the term was stated to mean, ‘‘like a butterfly resting on a branch,’’ ‘‘resembling butterflies sitting on a fence,’’  ‘‘butterflies alighting on shrubbery,’’ ‘‘vague resemblance in cross-section to a butterfly,’’ and a reference ‘‘to the scales of the butterfly wing.’’  While these colorful and useful metaphors evoked both the microscopic morphologic appearance and the possible aerogenous mode of dissemination, they were unrelated to the source of the term. Lepidic did not have an entomologic etymology.

John George Adami (left) first chair of pathology at McGill University (Montreal, Canada) and creator of the term lepidic. Lepidic pattern of adenocarcinoma, characterized by noninvasive surface alveolar growth of tumor cells (right).

Jones KD. Whence Lepidic? Arch Pathol Lab Med. 2013 Aug 12. 

(seen on http://timallenmdjd.blogspot.it/ via Twitter)

NSCLC Subtyping on Cytology – Meeting the Challenge

La necessità di sottotipizzare il carcinoma non a piccole cellule del polmone è divenuta ormai fondamentale per la scelta delle strategie terapeutiche più appropriate. In particolare, l' avvento delle terapie con farmaci anti tirosina chinasi specifici per i pazienti con adenocarcinoma ed EGFR mutato, ha reso indispensabile l' istotipizzazione anche sui "small tissue samples", che in oncologia polmonare sono molto spesso i soli campioni disponibili a causa dell' inoperabilità della maggior parte dei pazienti. La citopatologia può affrontare questa sfida perchè unisce ad una preservazione della citomorfologia superiore al campione bioptico, la possibilità di effettuare tecniche ancillari immunoistochimiche su cell block. Come mostrato efficacemente in da Cunha Santos et al. grazie alla correlazione cito-istologica in 602 aspirati polmonari con follow-up chirurgico (1), la diagnosi di istotipo è possibile, nella maggior parte dei casi, esclusivamente grazie alla citomorfologia. Infatti in questo lavoro si dimostra che, dopo revisione morfologica, solo il 17% dei NSCLC rimane non classificabile, necessitando di integrazione immunocitochimica. Ma anche per quest' ultima, contrariamente a quanto ci si potrebbe attendere, non si è osservato, nell' esperienza degli autori, un significativo incremento nemmeno in seguito alla introduzione della terapia targeted. Questo rinforza la conclusione per la quale (quasi) sempre la morfologia è in grado di assicurare una corretta sottotipizzazione, così da ottimizzare l' utilizzo del materiale aspirato per la biologia molecolare.

Gilda da Cunha Santos del dipartimento di Medicina di Laboratorio e Biopatologia dell' Università di Toronto, insieme ad altri ospiti italiani ed internazionali, interverrà giovedì 27 Settembre nel corso del III Molecular Cytopathology Meeting, presso il Centro Congressi Federico II in Via Partenope. Accorrete numerosi!  (per informazioni clicca QUI)

Bibliografia:

1) da Cunha Santos et al, Cyto-histologic agreement in pathologic subtyping of non small cell lung carcinoma: Review of 602 fine needle aspirates with follow-up surgical specimens over a nine year period and analysis of factors underlying failure to subtype. Lung Cancer. 2012 Sep;77(3):501-6.

Alterazioni del gene ALK nel carcinoma polmonare non a piccole cellule.

Il dott. Renato Franco si congratula per il nostro blog e mette a disposizione il pdf del suo interessante seminario.

Handout R.Franco

Travis WD, et al. International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinaryclassification of lung adenocarcinoma. J Thorac Oncol. 2011 Feb;6(2):244-85.