Thoracics Flashcards
Architectural patterns of lung adenocarcinoma. Which have poorer prognosis?
Lepidic
Acinar
Papillary
Micropapillary*
Solid*
Complex gladular*
Diagnostic criteria and clinical significance for micropapillary adenocarcinoma of the lung
Tumor cells grow in papillary tuft lacking fibrovascular cores, appearing to float within the alveolar septae
Must be distinguished from STAS
Micropapillary subtype is poor prognosis for overall survival and recurrence
Significance of TTF1 in lung cancer
Poorly differentiated CA: TTF1+ favours adenocarcinoma
AdenoCA: TTF1+ favours lung origin
Neuroendocrine: TTF1+ favours high grade neuroendocrine carcinoma. Usually neg in carcinoids
Definition and clinical significance of STAS
Free-floating tumor cell clusters or single tumor cells that are present in air spaces in surrounding lung parenchyma beyond edge of tumor
Represents aerogenous spread and is considered a pattern of invasion. Associated with increased rate of locoregional recurrence for pts who undergo sublobar resection
Main subtypes of SCC
Keratinizing
Nonkeratinizing
Basaloid
IHC positive in SCC as opposed to AdenoCA
HMWK eg CK5/6, p63, p40
DDx for lung SCC
Metastatic SCC
Metastatic urothelial CA
Thymic SCC
Squamous metaplasia
Main histologic features of basaloid SCC
Solid and trabecular growth, peripheral palisading, possible rosettes
Abrupt keratinization
Small monomorphic cells, hyperchromatic nuclei, absent/small nucleoli
High mitotic rate
Comedo-type necrosis
Called basaloid SCC if >50% basaloid component
DDx of basaloid SCC
High grade Neuroendocrine carcinomas
Poorly diff SCC or adenoCA
Adenoid cystic CA
NUT carcinoma
AIS vs MIS
AIS - solitary tumor with pure lepidic growth
- </= 3cm
- No invasion or STAS
- 100% disease free survival if lesion completely resected
MIA - solitary tumor with predominant lepidic growth
- Size </= 3cm
- invasive component </=0.5cm
- Exclusion criteria: invasion of vessels, air spaces, or pleura, tumor necrosis, STAS
- 100% disease free survival if lesion completely resected
Diagnostic criteria for SCCis
Full thickness of epithelium, without maturation
Large cells with marked anisokaryosis and pleomorphism are present
Increased NC ratio, coarse chromatin, nuclear angulations/folding
Mitotic figures present throughout full thickness
Diagnostic criteria and clinical significance of DIPNECH
Generalized proliferation of pulmonary neuroendocrine cells present in mucosa of airways
Lesions may be incidental or associated with chronic respiratory symptoms
Slowly progressive disease - may form tumorlets or carcinoid tumors
Diagnostic criteria of 4 main neuroendocrine tumors
Typical carcinoid: <2mits/2mm^3, no necrosis
Atypical carcinoid: 2-10mits/2mm^3 and/or foci of necrosis
Large cell neuroendocrine carcinoma: neuroendocrine morph and IHC
Small cell CA: small cells, poorly defined cell border, fine chromatin, nuclear molding, absent/inconspicuous nucleoli etc
Define combined small cell carcinoma
Admixture of small cell carcinoma with components of any type of NSCLC
For combined small cell and large cell, large ells at least 10% of cells present
Differentiate Large cell neuroendocrine carcinoma, NSCLC with neuroendocrine differentiation, large cell carcinoma with neuroendocrine morphology
Large cell neuroendocrine: NSCLC that shows neuroendocrine morphology and expresses NE IHC
NSCLC with neuroendocrine diff: NSCLC without NE morphology but + NE IHC
Large cell carcinoma with neuroendocrine morphology: morphology but neg IHC
Diagnostic criteria for neuroendocrine cell hyperplasia, tumorlet, and carcinoid
Neuroendocrine cell hyperplasia: prolif of NE cells confined to epithelium of airways without penetration through basement membrane
Tumorlet: prolif of neuroendocrine cells in bronchioles extending into surrounding tissue, </=0.5cm in size
Carcinoid: prolif of NE cells that forms nodule >0.5cm
NE immunostains, localization and utility
Chromogranin: cytoplasmic, specific but not sensitive for Ne cells. More sensitive in benign than HG tumors
Synaptophysin: cytoplasmic staining, good specificity
CD56: membranous, most sensitive, least specific
INSM1: nuclear, highest sensitivity and spec
Define large cell carcinoma
Undifferentiated NCSLC waste basket
Diagnosis of exclusion - it lacks architectural, cytologic immunohistochemical features of SCLC, adenoCA and SCC
Requires resected tumors
Diagnostic criteria of adenocaquamous
Admixture of adeno and SCC components
Each component at least 10% of tumor
May be suggested on small specimen but diagnosis requires resected tumors
Pleomorphic CA vs carcinosarcoma
Pleomorphic CA: poorly diff CA composed of any type of NSCLC that contains at least 10% spindle and/or giant cells, or a carcinoma consisting only of spindle or giant cells. Expression of epithelial markers helps establish diagnosis. Aggressive tumors, often high stage and associated with poor prognosis
Carcinosarcoma - consists of mixture of NSCLC and sarcoma-containing heterologous elements. Prognosis usually poor
Classic features of pulmonary blastoma
Biphasic pattern - primitive epithelial component resembling fetal bronchioles embedded in sarcomatous mesenchyme with embryonic appearance
Tubules lined by pseudostratified, nonciliated columnar cells and have subnuclear or supranuclear vacuoles
Histologic features of lymphoepithelioma-like carcinoma and it’s clinical significance
Poorly diff CA with syncytial pattern of growth, large tumor cells with prominent nucleoli, marked lymphocytic infiltrate and pushing borders (sounds like medullary)
IHC squamous
Presence of EBV
Better survival than other carcinomas
Define NUT carcinoma and described it’s clinical, histological, and genetic features
Aggressive, poorly diff CA associated with rearrangement in NUT gene
Clinical: large midline mass extending into hilar structures
Histo: sheets and nest of monomorphic cells with prominent nucleoli. Focally abrupt keratinization may be seen, infiltrating neutrophils
IHC: Variable with epithelial markers, SCC more often than TTF1 or NE markers. Diffuse nuclear staining present with NUT antibody
Genetic: translocation NUTM1-BRD3/4
List salivary gland type tumors occuring in the lung
Mucoepidermoid CA
Adenoid cystic CA
Epithelial-myoepithelial CA
Pleomorphic adenoma