HK Society of Cytology Seminar

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HK Society of CytologySeminar Workshop, 22
June 2002FNA OF LIVERDiagnostic problems

Dr. Wilson MS Tsui Dr. May FY Cheng Caritas
Medical Centre
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Why FNA of Liver, not Bx?

• Limitations
• Sample small
• Architecture lost
• Tumor typing problematic
• False negative
• Dx must be made within the known clinical context

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FNA of Liver - Advantages

• Small ? screening program
• Safe
• Multiple sampling
• Immediate microscopic assessment
• Adequate specimen guaranteed
• Treatment simultaneously

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Diagnostic Problems

• Very well-differentiated hepatocellular lesions
• - benign vs malignant
• Poorly differentiated neoplasms
• - typing primary vs metastatic
• Unusual tumors

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Clinical Information of importance

• Serum AFP Hepatitis viral markers
• - AFP gt1000 ng/ml highly suggestive of HCC
• - 80 HCC HBsAgve
• Presence or absence of cirrhosis
• - 85 HCC cirrhotic
• Size of lesion / Radiographic appearance
• - DN gt2cm (in cirrhosis) mostly malignant
• Sex / Age

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Usefulness of Cell Block

• Does not add to the detection (if obtained during
  the same pass), but helpful for confirming nature
  and cell type
• Trabeculae formation and cell plate thickness
• Evaluate reticulin framework
• Identify pigments
• Immunohistochemistry

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NORMAL LIVER

• Hepatocytes
• Small cores, forming multilayered chunks with
  rounded or squared edges
• Monolayered sheets, small clusters, single cells,
  naked nuclei
• Polygonal cell with abundant granular well
  defined cytoplasm
• Cytoplasmic fat, MH, bile, iron, lipochrome
• Round but variably sized nuclei, ?small nucleoli
• Intranuclear inclusions or vacuoles
• Single or double cell plates
• Preserved reticulin framework

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NORMAL LIVER

• Bile duct cells
• Small clusters or flat sheets with honeycomb
  pattern
• Small monotonous cells with uniform round nuclei
  and micronucleoli
• Cytoplasm scanty, columnar appearance
• Kupffer cells Endothelial cells
• Not easy to identify with certainty
• Mesothelial cells

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REACTIVE CONDITIONS and REGENERATIVE NODULES IN
CIRRHOSIS

• Hepatocytes may be either larger or smaller than
  normal cells
• Anisokaryosis, nuclei may be larger with more
  prominent nucleoli (large cell dysplasia)
• Dissociation may be very prominent
• Binucleate or even multinucleated cells
• àRisk of overdiagnosing malignancy

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HEPATOCELLULAR CARCINOMA Architectural patterns

• Trabecular (most common, 70-80)
• tight cohesive geographic island groups
• peripheral pattern and central pattern
• Pseudoglandular
• central clearing acinar or tubular arrangement
• Dispersed cell, with naked nuclei
• Combination of above

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HEPATOCELLULAR CARCINOMA Cytological features

• Cellular smear
• Polygonal cells resembling hepatocytes with
  increased N/C ratio and prominent nucleoli
• Pleomorphic or spindle cells (uncommon)

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HEPATOCELLULAR CARCINOMAMalignant features

• Excessive cellularity
• Trabeculae/cords/sheets of gt3 cells in width
• Obvious glandular pattern
• Loss of cell cohesion, atypical naked nuclei
• Usual nuclear features of malignancy nuclear
  pleomorphism, coarse chromatin, eosinophilic
  macronucleoli
• Smaller cell size with increased N/C ratio (can
  be large cell) nuclear crowding
• Cellular monomorphism
• Occasional large multinucleated hepatocytes
• Frequent mitosis

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HEPATOCELLULAR CARCINOMA Malignant features

• Negative findings
• No hemosiderin/lipofuschin pigment
• No normal hepatocytes within tumor cell clusters
• No bile duct epithelium in a cellular smear
• Not helpful
• Fat, Mallorys hyaline, bile
• Ancillary studies
• uLoss of reticulin framework
• uImmuno CD-34, Ki-67 / PCNA

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HEPATOCELLULAR CARCINOMAMalignant features

• Cohen Bottles. AJCP 199195125-130
• Step-wise logistic regression analysis of 10
  cytologic features
• (52 HCC vs 30 non-neoplastic)
• Key criteria
• Increased N/C ratio 71 vs 3
• Trabecular pattern 65 vs 10
• Atypical naked nuclei 73 vs 3
• à81 HCC had 2 or 3 criteria 29 all 3 only 1
  non-HCC had 2 sensitivity 100 specificity only
  87
• Secondary criteria
• Irregular granular chromatin 73 vs 13
• Uniformly prominent nucleoli in gt50 cells 60
  vs 20
• Multiple nucleoli 54 vs 7

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HEPATOCELLULAR CARCINOMAMalignant features

• Spain gp. Acta Cytol 199337309-316
• Stepwise logistic regression analysis of 28
  cytologic features
• (102 HCC vs 28 non-neoplastic)
• Most predictive criteria
• Irregular arrangement with nuclear crowding 82
  vs 14
• Irregular chromatin pattern 37 vs 0
• Uniformly smaller cytoplasm 29 vs 0
• àhighest sensitivity 84.3 specificity 100

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HEPATOCELLULAR CARCINOMAMalignant features

• French gp. Acta Cytol 200044515-523
• Stepwise logistic regression analysis of 39
  cytologic features
• (50 WD-HCC vs 50 MRN)
• Main criteria
• Increased N/C ratio 95 vs 0
• Cellular monomorphism 79
• Nuclear crowding 71
• Loss of bile duct cells 73 vs 7
• àoverall sensitivity 75 specificity 100

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HEPATOCELLULAR CARCINOMA Immuno predicting
malignancy

• CD34 (Acta Cytol 199842691-696
  200044218-222)
• Diffuse sinusoidal reactivity (capillarization)
  in linear or peripheral pattern ? 9/9,14/17 HCC
  cell block
• Pitfall gt50 sinusoidal staining in adenoma
  (5/7), FNH (4/9)
• UEA1 F VIII less sensitive, CD31 not helpful
• Proliferative markers
• KI-67 gt10 ve nuclei in HCC lt5 in MRN
• PCNA gt15 ve nuclei in HCC lt5 in MRN
• Pitfall patchy staining, count 1000 cells

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BENIGN HEPATOCELLULAR LESIONS

• Benign hepatocytes with cell plates ?3 cells
  thick and preserved reticulin
• Possibilities
• False negative (sampling error) or true negative
  (eg focal fatty change)
• Macroregenerative nodule / Dysplastic nodule
• Adenoma
• Focal nodular hyperplasia
• Partial nodular transformation (rare)
• àNeedle biopsy

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Cytologic Criteria for Dx of MRN, DN and wd
HCC French gp. Acta Cytol 200044515-523
N normal, ? slightly increased, ? ?
markedly increased.
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DYSPLASTIC NODULE Low grade

• Clinical setting ?1 cm nodule in cirrhosis
• Large cell dysplasia or normal cytology
• Dx NEOM, but a low grade DN cannot be excluded
• àNeedle core biopsy, not just cell block

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DYSPLASTIC NODULE High grade

• Clinical setting ?1 cm nodule in cirrhosis
• Irregular cell plates up to 3 cell thick
• Small cell dysplasia featuring smaller cell with
  increased N/C ratio and cellular monomorphism
• àNeedle core biopsy, not just cell block
• Intact or focal decreased reticulin framework
• Lack of diffuse CD34 sinusoidal staining

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Imaging-guided FNA
Clinically SOL / HCC
note Size of tumour Any cirrhosis
Large HCC
Small HCCMacroregenerative nodule (³ 1cm)
Cytology Cell block
Cytology Cell block
inadequate
adequate smear
adequate
Repeat Aspirate
Equivocal(DN vs HCC)
DefinitiveHCC
Inadequate
Core Biopsy
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FNA OF LIVER

• Primary Vs Metastatic
• Typing of Tumor

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HCC vs Metastatic Carcinoma

• Frequent site of metastasis
• Easy with known primary, of medium-sized and
  small cells
• Difficult when the liver mass is the only lesion
• Especially when poorly differentiated and of
  large polygonal cells

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HEPATOCELLULAR CARCINOMA Hepatocellular
differentiation

• Malignant tumor clusters separated
  (transgressing) or surrounded (peripherally-wrappi
  ng) by endothelial cells sinusoidal trabecular
  pattern
• Polygonal cells with central nuclei and well
  defined eosinophilic granular occasionally
  vacuolated cytoplasm
• Bile plugs between tumour cells / in cytoplasm
• Intranuclear cytoplasmic inclusions
• Immuno Heppar-1, CK pattern, CEA, AFP

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HEPATOCELLULAR CARCINOMA Hepatocellular
differentiation

• Bottles Cohen. Cancer 198862558-563
• Step-wise logistic regression analysis(35 HCC vs
  74 metastatic CA)
• Key criteria
• Polygonal cells with centrally placed nuclei 94
  vs 15
• Malignant cells separated by sinusoidal
  capillaries 94 vs 20
• Bile 34 vs 0
• à97 HCC had 2 or 3 criteria 26 all 3 criteria
• 0 metastatic CA had 2 or 3 criteria 35 had
  1 criterion
• Secondary criteria
• Endothelial cells surrounding tumour cell
  clusters 77 vs 5
• Intranuclear cytoplasmic inclusions 71 vs 16

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HEPATOCELLULAR CARCINOMA Hepatocellular
differentiation

• Some help
• Granular well defined cytoplasm 91 vs 18
• Basophilic intracytoplasmic inclusions 11 vs
  0
• Not helpful
• Large nucleoli
• Multinucleated giant cells
• Small and large cytoplasmic vacuoles
• Eosinophilic intracytoplasmic inclusions
• Polymorphs

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HEPATOCELLULAR CARCINOMAImmuno indicating
hepatocellular differentiation

• 1980s
• AFP, A1AT
• 1990s
• CK pattern, pCEA, AFP
• 2000s
• HepPar-1, albumin mRNA,
• CK pattern, pCEA, AFP (serum)

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Primary Biliary Tumors

• Cholangiocarcinoma
• Mucinous cystadenocarcinoma
• Biliary papillomatosis

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CHOLANGIOCARCINOMAWell differentiated

• Sheets and clusters of cells resembling normal
  bile duct epithelium with some single cells
• But more abundant and broader sheets than
  expected in N
• Some nuclear enlargement, mild pleomorphism and
  subtle nuclear membrane irregularities
• Microglandular arrangement and nuclear crowding

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CHOLANGIOCARCINOMA Poorly differentiated

• Indistinguishable from other adenoca
• Particularly from those of pancreatic origin
• CK pattern
• CK7 CK20
• Cholangiocarcinoma -
• Colonic carcinoma -
• usually indistinguishable from those of
  extrahepatic biliary and pancreatic origin.

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Cholangiocarcinoma vs Metastatic ca

• Necrotic debris more common in metastasis,
  especially colonic ca
• Colonic adenoca usually columnar or cuboidal in
  shape and arranged in glands or in palisaded-like
  arrangement
• Signet ring cells in breast lobular ca / gastric
  ca

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Origin of Metastatic Cancer

• Challenging with occult primary outside liver
• First step is to identify and classify tumor
  cells in broad categories, eg adenoca, SCC,
  sarcoma, lymphoma, etc.
• Not very difficult in the majority of the cases
• Distinction between primary and metastasis
  adenoca is difficult and impossible in many cases

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Metastatic Adenoca

• Most common metastatic lesion
• Usually arises in GI tract or other abdominal
  organs
• Necrotic debris is more common
• Especially in metastases from colon

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Colon

• Usually columnar or cuboidal in shape
• Arranged in glands or a palisaded-like pattern
• Presence of mucus is a strong criterion for
  metastasis
• Not specific of any type of adenoca

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Breast(Ductal carcinoma)

• Singly and in clusters
• Round or oval, of varying sizes
• Fair amount of pink cytoplasm
• Nucleoli are often multiple and in eccentric
  location

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Breast(Lobular carcinoma)

• Indian file
• Small signet-ring cells, containing mucous
  cytoplasmic inclusions
• Signet-ring cells also seen in other adenoca

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Squamous cell carcinoma

• Round, tadpole-shaped, oval, spindle, or bizarre
  cells may occur
• Cytoplasm is dense and well demarcated
• Keratin-forming cells are common
• Angular nuclear outline
• Hyperchromatic and coarse chromatin
• Necrosis is common

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Melanoma

• Large cells, abundant cytoplasm brown granules
  of melanin
• Nuclei are large, single, or multiple
• Prominent nucleoli, intranuclear cytoplasmic
  inclusions
• Polygonal cells with centrally placed nuclei
  and nuclear inclusion also in HCC
• HMB-45 and CK recommended

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Small cell carcinoma

• Often not pyknotic and fairly well preserved
• Necrotic debris and smaller pyknotic nuclei can
  be found
• Cells are very fragile and non-cohesive with
  scanty cytoplasm
• Nuclear chromatin are frequently crushed

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Small cell carcinoma

• Round to cuboidal nuclear with irregular contour
  and coarse chromatin
• Nuclear moulding
• Inconspicious or absent nucleoli
• Mitotic activity usually absent

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Carcinoid tumor

• Smaller, more cohesive fairly uniform cells with
  slightly more abundant, intact cytoplasm than
  small cell carcinoma
• Necrosis usually absent
• Finely stippled chromatin
• Small nucleoli
• No mitotic activity

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Carcinoid tumor

• Spindle cells in spindle variant
• Atypical carcinoid may show features of both
  carcinoid and small cell carcinoma
• EM and immunostaining may be needed
• DDx Lymphoma, small cell carcinoma and other
  small cells neoplasm

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FNA OF LIVER

• UNUSUAL TUMORS

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HEPATOCELLULAR CARCINOMA

• Clear cell HCC
• Diffuse clear cell change as abundant pale finely
  vacuolated cytoplasm
• Nuclei tend to be eccentric
• àClear cell HCC or adenoma not normal
• Dx Renal cell ca, adrenocortical ca,
• ovarian clear cell ca

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HEPATOCELLULAR CARCINOMA

• Fibrolamellar HCC
• Discohesive cells, isolated or arranged in small
  groups and clusters, rather than in trabeculae
• Abundant oncocytic cytoplasm
• Markedly enlarged hepatocytes (3-4xN) with much
  enlarged nuclei
• Extremely prominent nucleoli
• Intracytoplasmic hyaline globules
• Well delineated pale bodies
• Lamellar fibrous stroma (as parallel bands of
  fibrous tissue and fibrocytes) may not be
  obvious require cell block or biopsy

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HEPATIC STEM CELL MALIGNANCIES Theise N,Tsui
W,... et al. AJSP (in press)

• HCC with stem cell components
• Malignant hepatocytes with clear cytoplasm
  arranged in trabecular and clusters
• Small undifferentiated cells with scanty
  basophilic cytoplasm and high N/C ratio, in
  clumps and tubules
• Intermixed or rimming

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COMBINED HCC / CCA

• Malignant hepatocytes arranged in trabecular and
  clusters, with well defined cell margins,
  granular cytoplasm, central nuclei, coarse
  chromatin and prominent nucleoli
• Cohesive columnar cells displaying nuclear
  palisading forming acini/papillary structures,
  with ovoid basal nuclei, less dense cytoplasm,
  fine chromatin and indistinct nucleoli
• Intermediate cells with hybrid/polymorphic
  features
• Mucin secretion, immuno characteristics

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HEPATOBLASTOMA

• Cohesive clusters, trabeculae and rosette/acini,
  as well as single cells and naked nuclei
• Fetal cells abundant granular or clear
  cytoplasm, little pleomorphism
• Embryonal cells high N/C ratio, round
  hyperchromatic nuclei with single inconspicuous
  nucleolus
• Extramedullary haemopoiesis
• Problems
• Predominantly fetal type component
• àresemble normal liver, adenoma
• Abundant embryonal or small-cell component
• àddx from other small cell tumors of childhood
• Macrotrabecular component
• àmimicking trabecular HCC

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BILIARY PAPILLOMATOSIS Tsui W, Lam P, Mak C, Pay
KH. Diagn Cytopathol 200022293-298

• Hypercellular smear
• Very broad and often double-cell layered sheets
  of biliary ductal columnar epithelium
• Papillary configuration
• Preserved honeycomb pattern with nuclear spacing
• Dysplasia but not frankly malignant nuclear
  features
• DDx
• Adenocarcinoma, primary or metastatic
• Papillary adenocarcinoma
• Dysplastic ductal epithelium

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MUCINOUS CYSTADENOCARCINOMA

• Suggested by radiologic cytologic findings
• Clusters of carcinoma cells in a mucinous
  background
• Indistinguishable from metastatic adenoca
• CK immunohistochemistry is often needed to
  confirm a primary liver origin

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HEMANGIOMA

• Quick rush of blood
• Paucicellular, endothelial cells seldom seen
• Fibrous septa occasionally tissue fragments of
  bland spindle cells arranged in a streaming /
  swirling pattern, 3-D arcades around empty spaces
• FNA contraindicated only if superficial and large

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ANGIOSARCOMA

• Highly cellular or diluted with blood
• Large fragments, loose clusters, and single cells
• Fragments of spindle cells forming
  interconnecting networks of tubular vessels
• Spindle cells with oblong hyperchromatic nuclei,
  lacy and ill-defined cytoplasm, variable N/C
  ratio and nucleoli
• Epithelioid cells in irregular clusters with
  abundant cytoplasm, vesicular nuclei and
  prominent nucleoli
• Large bizarre cells
• Intracytoplasmic hemosiderin common, and
  erythrophagocytosis characteristic

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EPITHELIOID HEMANGIOENDOTHELIOMA

• Non-bloody, hypocellular
• Polymorphic cells dispersed in a single cell
  pattern and occasional gland-like formation
• Folded nuclear contours, bi- and multinucleation
  common
• Delicate and hematophilic cytoplasm

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ANGIOMYOLIPOMA Ma T, Tse MK, Tsui W, Yuen KT.
Acta Cytol 199438257-260 Cha I, et al. Cancer
19998725-30

• Clusters of cells with arborizing transgressing
  endothelium but no peripherally wrapping
  endothelium
• Smooth muscle cells with fibrillary cytoplasm and
  indistinct cell borders
• Fat can be absent or scanty
• Hemopoietic cells may be present
• Intranuclear inclusions, nucleoli, and large
  atypical cells (?HCC) no mitosis
• Exaggerated trabecular arrangement in cell block
• àImmuno - HMB45, actin, etc

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CYSTIC MASS

• Infective cysts
• abscess, parasite
• Developmental cysts
• solitary cyst, polycystic disease, Carolis
  disease
• Cystic neoplasms
• cystadenoma/ca, teratoma, mesenchymal hamartoma
• cystic degeneration in 1? or 2? tumors, eg SCCa
• Miscellaneous
• multiple hilar cysts, traumatic

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SOLITARY NECROTIC NODULE Tsui W, Yuen R, Chow
L, Tse C. J Clin Pathol 199245975-978 De Luca
M, et al. J Surg Oncol 200074219-222

• Necrotic ghost cells
• Fibrosclerotic tissue capsule
• Must exclude necrotic tumor
• àCore biopsy - reticulin

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FNA of Liver

• Updated reviews
• 1.Guy CD, Ballo MS. Fine needle aspiration biopsy
  of the liver. Adv Anat Pathol 19996303-316
• 2.Tsui WMS, Cheng FY, Lee YW. Fine needle
  aspiration cytology of liver tumors. Annuals of
  Contemporary Diagnostic Pathology 1998, Volume 2,
  pp.79-93