USCAP Specialty Evening Conference:

Cytopathology“New and recent Developments in Cytopathology: A case based approach”

Sara E. Monaco, MDAssociate ProfessorProgram Director, UPMC Cytopathology FellowshipDirector of FNA Biopsy Service & Clinic, Children’s Hospital of Pittsburgh & UPMC-Shadyside HospitalUniversity of Pittsburgh Medical Center (UPMC)Pittsburgh, PA

ACCME/DisclosuresThe USCAP requires that anyone in a position to influence or control the

content of CME disclose any relevant financial relationship WITH COMMERCIAL INTERESTS which they or their spouse/partner have, or have had, within the past 12 months, which relates to the content of this

educational activity and creates a conflict of interest.

Dr. Sara Monaco declares she has no conflict(s) of interest to disclose.

Why did Dina choose me?• Even out the gender ratio

• 2 Female : 2 Male • Even out the geographical representation

• 1 West Coast (CA)• 1 Mid West (OH)• 1 South (TX)• 1 Northeast/East Coast (PA)

• Even out the political party representation • 2 Red (TX, OH) : 2 Blue (CA, PA)

• All the other female cytopathologists from Democratic Northeastern states said “NO”

Whatever the reason, I’m honored to be here!

Clinical History

• 40-year-old woman with history of inflammatory skin lesions diagnosed 2 years prior, now found to have a 4.6 cm soft tissue mass near the right psoas muscle, and FDG-avid sclerotic bone lesions.

• CT-guided FNA and Core biopsy with touch preparation performed of the soft tissue mass.

FNA smear, DQ, high power FNA smear, DQ, high power

FNA smear, DQ, medium & high power FNA smear, Pap, medium & high powerFNA smear, Pap, medium & high power

Questions you are thinking…..

• Is this really all there is?• Why is Dr. Monaco showing an

unsatisfactory cytology case at USCAP?• Did Dr. Monaco go on-site to determine if

the FNA was adequate?• If she was on-site, why didn’t Dr. Monaco

ask for a core biopsy?

Touch prep, DQ, high power

Touch prep, DQ, high power Core Biopsy, H&E, high power

Core Biopsy, H&E, high power

What type of cells are these?

Metastatic Renal Cell Carcinoma Adenocarcinoma

Granular cell tumorLiposarcoma Resolving hematoma

Granulomas

Fat necrosis

Benign Pleural Fluid

Factor XIIIa CD1a, Langerin, S100, CK

CD68 BRAF VE1

Dendritic cellsRole: Ag presentation

IHC: + S100, +CD1a

Langerhans cells in skin and bronchial epithelium

Interdigitating and dendritic reticulum cells in LN and spleen

Monocyte/MacrophagesRole: Phagocytic cells

IHC: +CD68, +FXIIIa

Tissue macrophagesOsteoclasts

MicrogliaKupffer cells

Circulating monocytes

Histiocytic Disorders

LCH Non-LCH

More Clinical History• 40-year-old woman with history of single system, cutaneous Langerhans

cell histiocytosis diagnosed two years prior to current case (No systemic dz).

• Then developed multiple papules on her extremity which were found to be +BRAFV600E and with different IHC profile, suggestive of a non-LCH.

• Upon imaging for further work-up, patient was found to have:• FDG-avid (SUV= 7.8) calcified thyroid nodule • 4.6cm soft tissue mass antero-medial to right psoas muscle at level L5-S1 with moderate FDG

uptake (SUV=3.8)• Multiple mildly FDG-avid sclerotic lesions in axial skeleton (L1, sacral ala) measuring 1.7cm in

greatest dimension (SUV 2.5)• Diffuse hyperdensity of bone marrow in bilateral femur, tibia, and fibula with increased FDG

uptake (SUV 2.5-2.9)

Final Pathological Diagnosis• Soft tissue infiltrate, Pelvic, CT-guided Fine Needle Aspiration:

• Less than optimal- scant cellularity.• Atypical cells present.• Atypical histiocytic proliferation.

• Soft tissue infiltrate, Pelvic, CT-guided Core Biopsy with TP:• Histiocytic proliferation/neoplasm, compatible with Erdheim-Chester

Disease.

Initial Presentation (LCH) Later Presentation (non-LCH)

Johnson WT et al, J Cutan Pathol, 2015

CD1a

Langerin BRAF VE1

BRAF VE1Langerin

CD68

Thyroid Nodule in Patient with ECDFNA suspicious for PTC.  +BRAF V600E

Thyroid Nodule in Patient with ECDHistology:  +PTC with involvement by Histiocytosis

Final Impression & Follow-up

• Young woman with the following 3 entities (all + BRAFV600E):• Cutaneous Langerhans cell histiocytosis• Erdheim Chester Disease• Papillary thyroid carcinoma

• Follow-up: Treated with methotrexate and Imuran (Azathioprine) with partial clinical resolution of skin lesions and bone lesions, but required stenting of ureter due to fibrosis

Erdheim-Chester Disease (ECD)• Non-Langerhans cell histiocytosis• Polyostotic sclerosing histiocytosis• Onset: Middle adult age (approximately 50 years of age)• Clinical symptoms: Bone pain (most frequent), Back pain, Renal

pain/dysfunction, Exophthalmos with yellow bumps on eyelids, problems with coordinated movements, skin lesions

• Locations: bone, retroperitoneum (“hairy kidney”), & CNS• Disease course: Ranges from single system disease (focal lesions, bone

only) to multisystemic & fatal disease (multiple visceral organ involvement)• Prognosis appears to be worse than other histiocytoses, so

important to diagnose

ECD: Clinical presentation• Osteosclerotic bone

lesions• Bilateral, symmetrical

involvement of long bones

• metaphysis & diaphysis• sparing epiphyses

• >50% have extraskeletal component

• kidney, skin, brain, lung

Volpicelli ER et al, J Cutan Pathol, 2011

ECD: Historical Aspects• First 2 cases of ECD reported by Jakob Erdheim (Austrian

pathologist) & William Chester (American pathologist) in 1930• Referred to the disease as a distinctive form of lipoid granulomatosis

with bony disease• Third case later reported by Dr. Ronald Jaffe (UPMC), who

coined the term ECDFig.: Professor Jakob Erdheim in the Vienna Municipal Hospital MorgueReferences: Romm S (1987) Jakob Erdheim: Eminent Pathologist of Vienna.American Journal of dermatopathology 9: 447-450• Professor Jakob Erdheim an eminent Austrian pathologist• Beside other complex syndromes, the craniopharyngioma, was originallynamed after him - "Erdheim Tumor".

ECD: Cytological Findings• Cytology:

• Lipid-laden foamy histiocytes • Touton-type giant cells• Bland spindle cells/fibrosis• No nuclear grooves• No eosinophils• No Birbeck granules on EM• No cytological/nuclear atypia

Purgina B et al, Cytojournal 2011

ECD: Histological Findings

ECD: xanthogranulomatous & fibrotic histology

CD68

• Histology: • Xanthogranulomatous infiltrate• Marked fibrosis

ECD: Immunohistochemical Findings• Positive IHC: + CD68, CD163, Factor XIIIa, fascin (+/- S100)

• Xanthogranuloma phenotype CD163/CD68/CD14/fascin/FXIIIa

• Negative IHC: - CD1a, Langerin, CK (usually S100)

IHC of Histiocytic/Dendritic TumorsTumor LCA CD68 S100 CD21/35 CD1a Other

Rosai-Dorfman disease + ± + - -Langerhans cell

histiocytosis/sarcoma± ± + - + Langerin (CD207), BRAF VE1

Erdheim Chester Disease ± + ± - - CD163, CD14, Fascin, FXIIIa,BRAF VE1

FDC sarcoma - - 10% + - D2-40, clusterin, EMAIDC sarcoma ± ± + - -

NOTE:Same IHC

profile as JXG, but clinical

presentation and age differ.

ECD: Molecular Findings• Molecular: BRAF V600E mutations occur in 57-69%

patients with isolated LCH and in 54-82% patients with isolated ECD

• BRAF Mutation occurs in LCH & ECD • Similar molecular signature (activating mutations in MAPK pathway genes)• May impact future classification (inflammatory myeloid neoplasms)• “Mixed Histiocytosis” cases do exist: cases with overlap between LCH/ECD

• No BRAF mutation in other non-LCH histiocytosis• e.g. Rosai-Dorfman disease, cutaneous juvenile xanthogranuloma, histiocytic sarcomas, xanthoma

disseminatum, interdigitating dendritic cell sarcoma, & necrobiotic xanthogranuloma

Neoplasms that are positive forBRAF V600E

Metanephric adenoma of the kidneyPapillary craniopharyngioma

Pleomorphic xanthoastrocytomaAmeloblastoma

Langerhans cell histiocytosisErdheim Chester Disease

Hairy cell leukemia-classic (Not in HCL-variant)

Papillary thyroid carcinomaColonic adenocarcinoma

Malignant Melanoma

BRAF Testing• IHC (BRAF immunostain VE1)

• Monoclonal Ab (VE1) to detect mutant BRAF V600E protein expression

• Faster & cheaper• High specificity & sensitivity• Pitfall: Heterogeneity in BRAF expression• Positive result: strong cytoplasmic staining

• PCR• Sanger Sequencing• Next generation sequencing (NGS)

Busam KJ et al, Am J Surg Pathol 2013

BRAF VE1 IHC (control)

BRAF VE1 IHC (our case)

ECD: Treatment

• Cutaneous• Treatment aimed at systemic dz

• Systemic• Interferon-alpha• Systemic chemotherapy• Glucocorticoids• Radiotherapy• Vemurafenib (BRAF inhibitor)

Hyman DM et al, NEJM, 2015

ECD & LCH Overlap (“Mixed Histiocytosis”) • Rare, but can occur• Middle age onset (median age 43 yo)• 48% concurrent, 52% present with LCH that develops to ECD• Cutaneous lesions: more common in LCH

• LCH: 40%; plaques• ECD: 25%; xanthelasma and reddish papules

• Bone lesions: bilateral sclerotic bone involvement in ECD (95%) and at least 1 other organ system involved, including retroperitoneal fibrosis

Age comparison in Histiocytoses:

50s: ECD40s: Mixed30s: LCH

Comparison of Systemic Histiocytic DisordersECD, LCH, RDD

Diamond EL et al, Blood 2014

ECD LCH RDDImmunoprofile

CD68 & CD163CD1a & Langerin

S100FXIIIa

+-

- or weakly ++

+++-

+-+-

HistologyTouton giant cells

Xanthomatous infiltrateFibrosis

Emperipolesis

+++-

----

---+

Birbeck granules on EM - + -BRAF V600E mutation + + -Organs affected Long bones (femur,

tibia),Perinephric or

Retroperitoneal, Xanthelasma or

yellow skin plaques

Lung, craniofacial bones, scaly erythematous

patches on skin

Lymphadenopathy, firm papules of skin

ECD: Differential Diagnosis• Non-diagnostic/non-specific findings• Non-neoplastic xanthogranulomatous proliferation• Fat necrosis• Malakoplakia• Hemophagocytic syndromes• Other Histiocytoses

• LCH• Non-Langerhans cell histiocytosis

• Clear cell type neoplasms (e.g., Metastatic RCC)• Sarcoma (e.g., Liposarcoma)• Spindle cell proliferation (e.g., Fibromatosis)

Langerhans cell histiocytosis

CD1a

Rosai‐Dorfman Disease 

Dendritic Cell Sarcoma

Images courtesy of Dr. Liron Pantanowitz

CD21

Granular Cell Tumor

S100 PAS

Xanthogranulomatous Pyelonephritis

Images courtesy of Dr. Walid Khalbuss

Malakoplakia

Atypical Mycobacterial Infection AFB Desmoid‐type Fibromatosis Actin

Beta‐catenin

Take Home Messages• Histiocytic lesions/neoplasms can be challenging

• Correct classification requires correlation with the clinical features• Xanthogranulomatous lesions with fibrosis may be scant on

FNA/TP or mistaken as normal on nonDx findings on CNB• The presence of the BRAFV600E mutation in any XG-type lesion

should prompt a work-up for ECD

• Utility of ancillary testing• Molecular studies or IHC for BRAF mutations or mutated protein• Exclude other types of histiocytoses and non-histiocytic neoplasms

(e.g. granular cell tumors & mimics)

Diagnostic Challenges• Small biopsies and cytology specimens from histiocytic

& fibrotic lesions may be a challenge

• Acquisition Challenges• Sampling issues due to focal or patchy disease • Need to correlate pathology findings with radiology

• Interpretation Challenges• Be careful not to dismiss findings as NonDx or Negative• Need to have suspicion in order to initiate IHC panel• Histiocytic markers can be challenging to interpret

Cautionary Note• Histiocytic markers can be tough to interpret• Best to use a panel

Metastatic Adenocarcinoma in Pleural Fluid CD68 MOC31

Cautionary Note• Don’t fight with the radiologist/clinician!• There really may be something in the CNB if TP is scant.