ECP 2017 - Abstract Book

Although these lesions were considered as of fibrohistiocytic origin, their

histogenesis is yet to be clarified. A case has been presented diagnosed

with this rare and underrecognized entity.

Method:

A nodular lesion of 3,5 cm in diameter, covered with normal

appearing skin was observed in an amputation material from a 54 year old

female patient, resected because of a mass localized at left first toe

’

s plantar

side.

Results:

Histopathological examination revealed a nodular lesion localized at

subcutaneous tissue, infiltrating bone and involving distal interphalangeal

joint was seen. Lesion was consisting of plump spindle cells arranged in short

strands or storiform pattern, accompanied by inflammatory response.

Conclusion:

Evaluated as a variant of malignant fibrous histiocytoma

initially, PFHT is reclassified as a fibrohistiocytic tumour of intermediate

malignant potential by World Health Organization. The entity has high

local recurrence rates, though metastases are rare. No recurrence has been

observed in our case after the operation.

PS-23-039

Periostin expression in chondroid tumour

J. Y. Jeong

, D. Kim, H.-J. Kim, W. Jeong

Kyungpook National University, Pathology, Daegu, Republic of Korea

Objective:

Periostin is a secreted extracellular matrix protein that is

consisted by 4 fasciclin-1 domains. Periostin is secreted by osteoblast

and exists on periosteum. It is involved in bone formation as a key reg-

ulator of bone microarchitecture, strength and mass. Periostin is secreted

from fibroblasts in some carcinoma and metastatic lung. It is also reported

that periostin is expressed in osteosarcoma and its expression level is

correlated with tumour angiogenesis and poor prognosis in osteosarcoma.

However, periostin expression on chondroid tumour has not reported yet.

The differential diagnosis of low grade chondrosarcoma from

enchondroma is important, however it is not easy. Periostin expression

in chondroid tumour was analyzed in this study.

Method:

Immunohistochemical stain for periostin was performed

on 61 cases of chondroid tumour, including 28 enchondromas and

33 low grade chondrosarcomas. 13 cases of normal cartilage were

also included as a control group. Percentage and area of positive

staining were evaluated. The area was subdivided as nucleus,

cytoplasm, and extracellular matrix.

Results:

In contrast to all normal cartilage tissue was negative for

periostin, 60 cases (98.4 %) of chondroid tumour showed positivity for

periostin in any area. Considering a strong and diffuse stain pattern in

most of the tumour cells achieved the best results in diagnosis of

chondroid tumour (sensitivity 97.0 %, specificity 96.4 %)

Conclusion:

In this study, we show the expression of periostin in

chondrosarcoma and enchondroma. We suggest periostin is a novel bio-

marker of chondrosarcoma to distinguish with enchondroma.

PS-23-040

Diagnostic pitfalls in telangiectatic osteosarcoma

B. Doganavsargil

, B. Kececi, B. Ozcanyuz, M. Sezak, M. Argin, H.

Ozdemir, F. Oztop

Ege University, Dept. of Pathology, Izmir, Turkey

Objective:

Telangiectatic osteosarcoma (TelOS) is a rare subtype, account-

ing 3

–

10 % of osteosarcomas. It is characterised with large, nonsclerotic-lytic,

destructive tumours with blood-filled cystic cavities lined by atleast focally

osteoid producing neoplastic cells. Resemblance to aneurysmal bone cyst

(ABC) is diagnostically concerning.

Method:

We reviewed 37 specimens of 11 TelOSs and 10 TelOS-

mimicking cases evaluated between 2000 and 2016. TelOS-mimickers

were defined as cases with ABC-like features or extensive hemorrhage;

notable TelOS-like component in biopsy specimens which is focal/

lacking in resections or cases with cystic changes in postchemotherapy

resections.

Results:

The median age for TelOSs were 16 ± 9.3 years-old (Range:6

–

43 years), were more frequent in males (82 %), mostly located in proxymal

tibia (46 %), humerus (36.4 %), distal femur (18.2 %), significantly involved

epiphysis (83.3 %,

= 0.06, chi-square), with a median diameter of 10.2 ± 5

(Range: 5

–

17 cm). Neoadjuvant chemotherapy responce was divergent

(Huvos grade I-III), however difficult to interpret for extensive cytic nature

of lesion. Three cases presented with pathological fracture (28%), two (18%)

with satellit tumours, two with accompanying ABCs. Re-biopsy/open biopsy

was done in 3 cases (28 %). For other osteosarcomas with TelOS-like areas

(23.8 %), metaphyseal involvement were more frequent (%60) and median

age was higher (21 ± 11.6).

Conclusion:

Paucity of neoplastic tissue in biopsies due to cystic nature of

tumours or so-called

“

Hemorrhagic-necrotic variant

”

of TelOS with sparse

osteoid production are the major pitfalls in trucut biopsies. More-confusing,

conventional osteosarcomas may present with ABC/ABC-like/TelOS-like

component which needs further evaluation with their affect on diagnostic

outcome.

PS-23-041

Comparative analysis between growth factors of epiphyseal plate

(SOX-9,Runx-2,Ihh,PTH-rP) and BCL-2 in benign and malignant

cartilaginous tumours. Correlation with clinical and morphological

findings

E. Amstalden

, A. Nascimento, F. Cintra

UNICAMP, Dept. of Pathology, Campinas, Brazil

Objective:

To evaluate the expression of the growth factors of

epiphyseal plate (SOX-9, Runx-2,Ihh, PTH-rP) and BCL-2 in car-

tilaginous tumours, correlating with histological grade and clinical

outcome.

Method:

27 enchondromas, 55 conventional chondrosarcomas (CSs: 24 low

grade-CS1; 31 high grade-CS2 + 3), 4 clear cell chondrosarcomas and 3

mesenchymal chondrosarcomas were evaluated. Immunostaining was ap-

plied and a score, according to Zhu

et.al,

2013 (modified), was used for

analysis.

Results:

Poor outcome was associated with high grade CSs,

chondrosarcomas developing in flat bone and with SOX-9 over-expression.

Higher levels of SOX-9 and Runx2 were found on cartilaginous tumours with

similar morphology to growth plate. PTH-rP and Ihh higher expression levels

were seen more often in enchondromas then in CSs, including when com-

paring with CS1, however, there was no difference of patients

’

outcome.

BCL-2 expression levels showed no differences either in histological grade

or in patients

’

prognosis.

Conclusion:

SOX-9 may help to predict patients

’

outcome with these carti-

laginous tumours. PTH-rP and Ihh overexpression could be useful in

distinguishing enchondroma from CS1. Expression of epiphyseal plate tran-

scription factors SOX-9 and Runx-2, in cartilaginous tumours with morphol-

ogy similar to the growth plate, may suggest a possible participation of these

molecules in the pathogenesis of these neoplasms. Grant:FAPESP-2015/

06639-9.

PS-24-001

Diagnosis of thymoma by bronchoscopic biopsy

E. Bozkurtlar

, I. S. Isgör, D. Kocakaya, S. Olgun Yildizeli, R. A.

Ahiskali

Marmara University, Istanbul, Turkey

Wednesday, 6 September 2017, 09:30

–

10:30, Hall 3

PS-24 Thymic and Mediastinal Pathology

Virchows Arch

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2017

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