Traps in the Immunohistochemical Work-up of Spindle Cell Tumours

Transcription

1 BRENDAN C. DICKSON BA, BSc, MD, MSc, FCAP, FRCPC Staff Pathologist Head, Section of Immunohistochemistry Pathology and Laboratory Medicine Mount Sinai Hospital Assistant Professor Laboratory Medicine and Pathobiology University of Toronto Traps in the Immunohistochemical Work-up of Spindle Cell Tumours

2 DISCLOSURE I have no actual, or poten al, conflicts of interest in rela on to this presenta on to disclose

3 OUTLINE Goal Approach to avoid common immunohistochemistryrelated pi alls in the evalua on of spindle cell neoplasms Introduc on Three cases Case presenta on Differen al diagnosis audience par cipa on Discussion of pi alls and pearls Summary

4 INTRODUCTION Spindle cell Descrip ve term deno ng a bipolar cell with tapered ends

5 INTRODUCTION Architecture Cells Nuclei Fascicular Plump Round-ovoid-elongated Storiform Elongated Monomorphic-pleomorphic Herringbone Colour of cytoplasm Wavy Pa ernless Inclusions Ends: blunt, tapered, asymmetric Plexiform Nucleoli Mito c ac vity (incl. atypical figures) Ancillary findings Margins: circumscribed-infiltra ve Necrosis Vascular pa ern Inflamma on Extracellular matrix / stroma

6 INTRODUCTION Clinical history Diagnos c imaging Pathology Morphology Does it look like sarcoma, carcinoma, melanoma? Immunohistochemistry Addi onal ancillary studies Electron microscopy Molecular and cytogene cs

7 INTRODUCTION Basic spindle cell immunohistochemistry panel: Desmin Smooth muscle ac n CD34 S100 Kera n (AE1/AE3) Supplement & swap based on clinical context, morphologic impression, differen al diagnosis and/or need for redundancy

8 CASE 1 96 M. Excision right facial tumor. Spindle cell tumour, probable recurrent melanoma.

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15 CASE 1 Differen al diagnosis a) Desmoplas c / spindle cell melanoma b) Squamous cell carcinoma, spindle cell variant c) Atypical fibroxanthoma, spindle cell variant d) Pleomorphic dermal sarcoma e) I do not know, and require a panel of immunohistochemistry

16 S100 (original lab)

17 panmel (original lab)

18 Keratin (AE1/AE3) (original lab)

19 Smooth muscle actin (original lab)

20 Desmin (original lab)

21 CD34 (original lab)

22 Vimentin (original lab)

23 CASE 1 Differen al diagnosis a) Desmoplas c / spindle cell melanoma b) Squamous cell carcinoma, spindle cell variant c) Atypical fibroxanthoma, spindle cell variant d) Pleomorphic dermal sarcoma e) I STILL do not know, and require ANOTHER panel of immunohistochemistry

24 SOX10

25 Keratin (AE1/AE3)

26 p63

27 CASE 1 Differen al diagnosis a) Desmoplas c / spindle cell melanoma b) Squamous cell carcinoma, spindle cell variant c) Atypical fibroxanthoma, spindle cell variant d) Pleomorphic dermal sarcoma

28 CASE 1 Squamous cell carcinoma, spindle cell variant Pi alls: Loss of kera n(> 30%); NB: controls O en posi ve for vimen n, smooth muscle ac n Infiltra ng S100 posi ve dendri c cells Pearls: CK5/6 more sensi ve that AE1/AE3 p63 posi ve in majority (83-100%) p40 sensi vity, may be more specific Gleason BC, Calder KB, Cibull TL et al. J Cutan Pathol. 2009;36(5): Henderson SA, Torres-Cabala CA, Curry JL et al. Am J Surg Pathol. 2014;38(8): Ha Lan TT, Chen SJ, Arps DP et al. J Cutan Pathol. 2014;41(11):831-8.

29 CASE 1 Differen al diagnosis a) Desmoplas c / spindle cell melanoma b) Squamous cell carcinoma, spindle cell variant c) Atypical fibroxanthoma, spindle cell variant d) Pleomorphic dermal sarcoma

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32 S100

33 SOX10

34 HMB45

35 MART-1

36 CASE 1 Desmoplas c / spindle cell melanoma Pi alls: Loss of HMB45, MART-1 MiTF not sensi ve / specific Gain of smooth muscle ac n (30%), CD56 (50%) Vimen n posi ve Pearls: O en accompanied by lymphoplasmacy c inflamma on S100 and SOX10 typically robust Presently limited role for molecular Shain AH, Garrido M, Bo on T et al. Nat Genet. 2015;47(10): Hu enbach Y, Prieto VG, Reed JA. J Cutan Pathol. 2002;29(9): Longacre TA, Egbert BM, Rouse RV. Am J Surg Pathol. 1996;20(12):

37 CASE 1 Differen al diagnosis a) Desmoplas c / spindle cell melanoma b) Squamous cell carcinoma, spindle cell variant c) Atypical fibroxanthoma, spindle cell variant d) Pleomorphic dermal sarcoma

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42 Smooth muscle actin

43 CASE 1 Atypical fibroxanthoma, spindle cell variant Pi alls: Diagnosis of exclusion Pearls: Be skep cal outside prototypic clinical context Should not see kera n Moot point? Controversy as to whether represents dedifferen ated squamous cell carcinoma Calonje E, Wadden C, Wilson-Jones E, Fletcher CD. Histopathology. 1993;22(3): Gru AA, Santa Cruz DJ. Semin Diagn Pathol. 2013;30(1):4-12.

44 CASE 1 Differen al diagnosis a) Desmoplas c / spindle cell melanoma b) Squamous cell carcinoma, spindle cell variant c) Atypical fibroxanthoma, spindle cell variant d) Pleomorphic dermal sarcoma

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49 Smooth muscle actin

50 CASE 1 Pleomorphic dermal sarcoma Pi alls: Smooth muscle ac n o en posi ve (70%) CD31 o en posi ve (48%) Pearls: Deep, necrosis, LVI, perineural invasion may be present Miller K, Goodlad JR, Brenn T. Am J Surg Pathol. 2012;36(9):

51 CASE 2 32 M. Right arm mass involving brachial plexus

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56 CASE 2 Differen al diagnosis a) Malignant peripheral nerve sheath tumour b) Dermatofibrosarcoma, fibrosarcomatous variant c) Synovial sarcoma, monophasic d) Desmoid-type fibromatosis e) I do not know, and require a panel of immunohistochemistry

57 Desmin

58 Smooth muscle actin

59 CD34

60 S100

61 Keratin (AE1/AE3)

62 CASE 2 Differen al diagnosis a) Malignant peripheral nerve sheath tumour b) Dermatofibrosarcoma, fibrosarcomatous variant c) Synovial sarcoma, monophasic d) Desmoid-type fibromatosis e) I STILL do not know, and require ANOTHER panel of immunohistochemistry AND/OR molecular

63 CASE 2 Differen al diagnosis a) Malignant peripheral nerve sheath tumour b) Dermatofibrosarcoma, fibrosarcomatous variant c) Synovial sarcoma, monophasic d) Desmoid-type fibromatosis

64 CASE 2 Synovial sarcoma, monophasic variant Pi alls: Kera n (AE1/AE3) may be lost (30%) or focal S100 (38%), smooth muscle ac n (21%), CD117 (11%) Pearls: Dystrophic calcifica on; wiry collagen Plump overlapping nuclei EMA more sensi ve than panck (near 100%) TLE1 is a robust biomarker May show decreased INI-1 Pelmus M, Guillou L, Hostein I et al. Am J Surg Pathol. 2002;26(11): Terry J, Saito T, Subramanian S et al. Am J Surg Pathol. 2007;31(2):240-6.

65 CASE 2 Differen al diagnosis a) Malignant peripheral nerve sheath tumour b) Dermatofibrosarcoma, fibrosarcomatous variant c) Synovial sarcoma, monophasic d) Desmoid-type fibromatosis

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70 S100

71 SOX10

72 CASE 2 Malignant peripheral nerve sheath tumour Pi alls: S100 (30-67% of tumours), may be focal SOX10 (40-67% of tumours), may be weak/focal Heterologous smooth muscle, rhabdomyoblas c and epithelial differen a on Pearls: Clinical history occasionally points to NF1 Radiology / OR report may point to nerve origin Kang Y, Pekmezci M, Folpe AL et al. Mod Pathol. 2014;27(1): Nonaka D, Chiriboga L, Rubin BP. Am J Surg Pathol Sep;32(9): Karamchandani JR, Nielsen TO, van de Rijn M, West RB. Appl Immunohistochem Mol Morphol. 2012;20(5):

73 CASE 2 Differen al diagnosis a) Malignant peripheral nerve sheath tumour b) Dermatofibrosarcoma, fibrosarcomatous variant c) Synovial sarcoma, monophasic d) Desmoid-type fibromatosis

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75 CD34

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78 Smooth muscle actin

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80 CASE 2 Dermatofibrosarcoma protuberans, fibrosarcomatous variant Pi alls: Loss of storiform pa ern Loss of CD34 (19%) Myoid / myofibroblas c differen a on Pearls: Transloca on immutable Abbo JJ, Oliveira AM, Nascimento AG. Am J Surg Pathol. 2006;30(4): O'Connell JX, Tro er MJ. Mod Pathol. 1996;9(3): Calonje E, Fletcher CD. J Cutan Pathol. 1996;23(1):30-6.

81 CASE 2 Differen al diagnosis a) Malignant peripheral nerve sheath tumour b) Dermatofibrosarcoma, fibrosarcomatous variant c) Synovial sarcoma, monophasic d) Desmoid-type fibromatosis

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86 Desmin

87 Smooth muscle actin

88 Beta-catenin

89 CASE 2 Desmoid-type fibromatosis Pi alls: Entrapped skeletal muscle (myogenin and desmin may be misinterpreted as RMS or LGmyofibrosarcoma) Desmin may be focally posi ve Focal smooth muscle ac n O en nega ve for beta-catenin (~70% nuclear; lower in sporadic) Pearls: Early lesions may be myxoid +/- keloid-like collagen Late lesions have dense sclero c collagen Carlson JW, Fletcher CD. Histopathology. 2007;51(4): Ng TL, Gown AM, Barry T et al. Mod Pathol. 2005;18(1):68-74.

90 CASE 3 63 F. Two mesenteric masses

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94 CASE 3 Differen al diagnosis a) Dedifferen ated liposarcoma b) Leiomyosarcoma c) Mesothelioma, sarcomatoid variant d) Gastrointes nal stromal cell tumour, spindle cell variant e) I do not know, and require a panel of immunohistochemistry

95 H-caldesmon

96 CD34

97 CD117

98 DOG1

99 CASE 3 Differen al diagnosis a) Dedifferen ated liposarcoma b) Leiomyosarcoma c) Mesothelioma, sarcomatoid variant d) Gastrointes nal stromal cell tumour, spindle cell variant e) I STILL do not know, and require ANOTHER panel of immunohistochemistry AND/OR molecular

100 CASE 3 Differen al diagnosis a) Dedifferen ated liposarcoma b) Leiomyosarcoma c) Mesothelioma, sarcomatoid variant d) Gastrointes nal stromal cell tumour, spindle cell variant

101 CASE 3 Gastrointes nal stromal tumour, spindle cell variant Pi alls: 5% may be nega ve for CD117 O en posi ve for smooth muscle markers, including H- caldesmon (80%) Pearls: Pleomorphism is rare CD34 frequently posi ve (par cularly in spindle cell variant) In contrast to smooth muscle tumours, smooth muscle ac n and desmin are rarely diffuse Molecular o en reassuring Mie nen M, Lasota J. Arch Pathol Lab Med. 2006;130(10):

102 CASE 3 Differen al diagnosis a) Dedifferen ated liposarcoma b) Leiomyosarcoma c) Mesothelioma, sarcomatoid variant d) Gastrointes nal stromal cell tumour, spindle cell variant

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107 Desmin

108 Smooth muscle actin

109 CD34

110 S100

111 MDM2

112 in situ hybridization

113 CASE 3 Dedifferen ated liposarcoma Pi alls: Nonsensical immunoprofile (may express desmin, smooth muscle ac n, CD34, S100, others) Heterologous differen a on (may show: smooth muscle, rhabdomyoblas c, osteosarcomatous, others) Pearls: Search surrounding fat for atypia Recogni on of enlarged polygonal cells with dense eosinophilic cytoplasm MDM2 (IHC / FISH)

114 CASE 3 Differen al diagnosis a) Dedifferen ated liposarcoma b) Leiomyosarcoma c) Mesothelioma, sarcomatoid variant d) Gastrointes nal stromal cell tumour, spindle cell variant

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118 Desmin

119 Smooth muscle actin

120 H-caldesmon

121 DOG1

122 CASE 3 Leiomyosarcoma Pi alls: Differing criteria (gynecologic vs so ssue [M vs F in retroperitoneum]) Dedifferen ated leiomyosarcoma may show loss of typical immunophenotype May express CD117 (11.5% uterine LMS), and DOG1 (27% uterine LMS) Pearls: Perinuclear cytoplasmic vacuoles o en present H-caldesmon generally helpful Hormone receptors occasionally relevant Chen E, O'Connell F, Fletcher CD. Histopathology. 2011;59(6): Sah SP, McCluggage WG. J Clin Pathol. 2013;66(1):40-3

123 CASE 3 Differen al diagnosis a) Dedifferen ated liposarcoma b) Leiomyosarcoma c) Mesothelioma, sarcomatoid variant d) Gastrointes nal stromal cell tumour, spindle cell variant

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128 Keratin (AE1/AE3)

129 Calretinin

130 D2-40

131 CASE 3 Mesothelioma, sarcomatoid variant Pi alls: May have decreased expression of tradi onal markers: kera n (93%), D240 (79%), WT-1 (46%), calre nin (31%), Vimen n (91%) and SMA (60%) o en posi ve Pearls: Clinical History/ Radiology o en essen al to correct diagnosis Search for epithelioid cells / biphasic component Klebe S, Brownlee NA, Mahar A et al. Mod Pathol. 2010;23(3): Padge DM, Cathro HP, Wick MR, Mills SE. Am J Surg Pathol. 2008;32(1):123-7.

132 SUMMARY Technique Rigorous immunohistochemistry standards, including on-slide posi ve controls impera ve Interpreta on Tumours may aberrantly over / under express markers Review controls (including endogenous) Synthesize clinical informa on, diagnos c imaging and pathology findings; flesh-out immunohistochemical incongrui es Beware of morphologic mimics and employ redundancy in immunohistochemical panels Draw on literature for unexpected findings

133 Carlson JW, Fletcher CD. Histopathology. 2007;51(4): Ng TL, Gown AM, Barry T et al. Mod Pathol. 2005;18(1):68-74.