Armed Forces Institute of PathologyWashington, DC

MEDICAL FOREIGN BODIES: MEDICAL FOREIGN BODIES: A review of histopathologic and A review of histopathologic and

spectroscopic findingsspectroscopic findings

Michael R. LewinMichael R. Lewin--Smith, MB, BSSmith, MB, BSChief, Division of Environmental PathologyChief, Division of Environmental Pathology

Department of Environmental & Infectious Disease Sciences,Department of Environmental & Infectious Disease Sciences,Armed Forces Institute of PathologyArmed Forces Institute of Pathology

Disclaimer

The opinions or assertions contained herein are the private views of the presenter and are not to be construed as official or as reflecting the views of the US Department of the Army, the Department of Defense, or the Department of Veterans Affairs.

INTRODUCTION 1

• Medical exogenous or “foreign” materials are found in many types of anatomic pathology specimens.

• Most are incidental findings seen in histological or cytological material removed for other purposes, (e.g. dermal suture granulomas, lubricant in Pap smears).

• Some are removed because they are the cause of an undiagnosed lesion, (e.g. remote nylon suture placement), or are mimicking a pathologic condition (e.g. dental amalgam tattoo mimicking malignant melanoma).

INTRODUCTION 2

• Many medical foreign bodies are easily recognized by routine light microscopy, and do not pose a diagnostic problem for the pathologist.

• However, on occasion a fuller characterization becomes important especially to rule out other entities, such as infectious organisms, or endogenousmaterials, (e.g. melanin vs. dental amalgam), and in some instances can confirm the diagnosis, (e.g. cutaneous deposits of silver in argyria).

INTRODUCTION 3

Medical materials may be found in tissue:-1. As an expected result of the therapeutic or

diagnostic intent, (e.g. suture granuloma)2. As an unexpected result of therapeutic or

diagnostic intent, (e.g. barium sulfate aspiration)3. As a result of unintended use or misuse of the

material, (e.g. constituents of oral medication within blood vessels of IVDUs)

4. As an artifact, (e.g. transport of biopsy on gauze)

INTRODUCTION 4

• The pathologist’s task of characterizing medical foreign bodies may be hampered by:-

1. Lack of relevant clinical history2. Lack of familiarity with morphological

features, (esp. recently introduced materials)3. Lack of familiarity with, and access to

additional studies and methods for characterization

INTRODUCTION 5

• Medical uses of exogenous materials are widespread, and will likely increase.

• New medical materials and devices will continue to appear in pathology specimens.

• Infrared spectroscopy, Raman laser spectroscopy, and scanning electron microscopy with energy dispersive X-ray analysis are non-destructive techniques that can help to characterize medical “foreign bodies” in pathology specimens, even when very limited material is available.

Scanning Electron Microscopy with Energy Dispersive X-ray Analysis

(SEM/EDXA)● First introduced in the 1960s● Is a method for determining the elemental composition of a

particle that can be localized in a tissue section● Generally provides qualitative information, but methods for

quantitative SEM/EDXA are available particularly for materials for which laboratory standards of known composition are available

● Elements with atomic numbers less than 6 (carbon), are not detectable without special adaptations. (5 B, 4 Be, 3 Li, 2 He, 1 H).

SEM/EDXA Samples

● Routinely we place an unstained 5µm section on a carbon disc, and place the adjacent section from the paraffin block on a glass slide for H&E staining.

● Localize area of interest on H&E and compare to the carbon disc

● No coating necessary, but background contains carbon (C)

SEM/EDXA Samples [cont.]

• If only an original stained section is available on glass, SEM/EDXA can still be useful, (e.g. for silver in argyria) .

• Remove coverslip • Background glass examined away from the

specimen, will contain elements in glass, (usually Si, O, Ca). (Na, Mg, Al, Cl, K, variably present).

• Occasionally a stained section can be transferred to a carbon disk.

• Consider possibilities of stain artifacts, (High mag)

Electron gun

(SEM)Energy Dispersive X-Ray Spectroscopy (EDX)• Electron beam causes inner-shell electron to be ejected

• As outer electrons “fill-in”, X-rays emitted

• Energies of X-rays are characteristic

• Elemental composition

Emitted X-rays

Electron beam

specimen

Energy Diagram Spectrum

C

O

SiP

Energy (keV)

Argyria: Scanning electron microscopy

5 µm

Argyria: SEM/EDXA demonstrates presence of silver (Ag), sulfur (S) and selenium (Se).

5 µm

Argyria: SEM/EDXA mapping for sulfur (S), silver (Ag), and selenium (Se).

Infrared and Raman Laser Spectroscopy (IR) & (Raman)

• Became available in 1940s (IR), 1960s (Raman), with subsequent developments

• Gives a molecular “fingerprint” that can be compared to reference spectra

• Unstained 5µm section adjacent to H&E stained section or carbon disc section placed on aluminum coated (reflective) glass slide or semi-reflective slide (more expensive)

Vibrational Microspectroscopy:(Infrared and Raman laser)

• Advantages– Rapid– Non-destructive– High-quality spectra– Identification

• Limitations– Spatial resolution

10µm (IR), 0.5µm (Raman)

– Sample thickness– Special slide material

Infrared Spectroscopy• Absorption of infrared light

• Probes energies of molecular vibrations (and rotations)

• Molecular “fingerprint”

• Non-destructive

• 10-µm spatial resolution

Light source

Energy Level Diagram Spectrum (%T or %R)

ν1ν2ν3

ν3

ν2

ν1∆ν3 ∆ν2 ∆ν1 Absorption

Eo

Silicone infrared spectroscopy (I.R.)

Silicone infrared spectroscopy (I.R.)

∆ννο+∆ν

∆ννο-∆ν

0νο

Anti-Stokes (I)Stokes (III)

Rayleigh (II)

virtual states E1

Eο

ν1

ν2

∆ν

νο I II IIIPhoton

absorbedPhotonemitted

Energy Level Diagram

hνο

RayleighScattering

(II)hνο

Anti-Stokes

Scattering (I)

h(νο+∆νο)Stokes

Scattering (III)

h(νο-∆νο)

LASER

Raman Spectroscopy• Inelastic scattering phenomenon• Laser based technique• Probes energy of molecular

vibrations• Molecular “fingerprint”• Low light effect• 0.5-µm spatial resolution

Nylon Raman Microspectroscopy

(two excitation wavelengths)

MATERIALS

• Silicone, Cellulose, Nylon, Polypropylene• Polylactic/polyglycolic acid copolymer• Dental amalgam• Acrylic polyamide plastic embolization material• Barium sulfate• Silver (Argyria)• Polystyrene sulfonate, Crospovidone (PVP)• Talc

Silicone ((poly)dimethylsiloxane)

• Silicon: Si, element• Silica: SiO2, inorganic (mineral) form of Si• Silicone: R2SiO, an organic form of silicon• Medical silicone: poly(dimethylsiloxane)• Oil, gel, rubber/elastomer

Medical Uses of Silicone

• Implants: breast, testis, others• Coating for needles, sutures, syringes, pacemakers • Antifoams for gastric bloating/flatulence• Maxillofacial reconstruction (elastomer)• Post vitrectomy (proliferative retinopathy)• Tubing, G.I., I.V., and intra-arterial• Hydrocephalus shunts• Arthroplastic implants, hand and foot• Other

Silicone: Breast implant histopathology

• LOCAL:• Fibrous capsule, may become mineralized.• Inflammatory cells: Macrophages, T-cells,

giant cells, occasional plasma cells• “Pseudosynovium”: Ultrastructurally contains

macrophage-like and secretory cells, no basal lamina, few cell junctions

Silicone: Breast implant histopathology

• SILICONE MIGRATION:• RUPTURED IMPLANTS: Breast (silicone

granuloma), lymph nodes, lung, pleural cavity, kidney, liver, ovary, adrenals, pancreas, brain, skin & joints

• NON-RUPTURED IMPLANTS: Capsule, lymph nodes, skin, scar, synovium, alveolar macrophages, spleen, liver (Kupffer cells)

Silicone: identification in tissue

• By light microscopy, refractile, colorless, non-staining, non-birefringent (“non-polarizable”), gel-like substance

• Found within phagocyte vacuoles or extra-cellularly, especially lining partially “washed-out” spaces

• More easily seen in thicker sections, lowering condenser, (finger under the condenser), phase contrast or darkfield microscopy

• Identification by infrared (I.R.) and/or Raman spectroscopy

Breast capsule “pseudosynovium”: H&E

Refractilematerial in capsule; H&E

Perivascular silicone, near breast prosthesis, H&E

Silicone infrared spectroscopy (I.R.)

Silicone (short arrows) in giant cell with asteroid body (long arrow); H&E (lymph node)

Silicone in giant cell with asteroid bodies; (lymph node), H&E

Silicone: Axillary lymph node

Cellulose

• Present in tissue as cotton, wood splinter, food particles (aspiration), IVDU (microcrystalline cellulose from oral medications), contaminants

• Does not stain well with H&E• Birefringent under polarized light• GMS +• Unmodified cellulose is PAS +• Esters e.g. cellulose acetate may be PAS -

Cellulose (cont.)

• Generally Sirius red +, (use amyloid procedure); stains pink to red

• Other direct cotton dyes that have been suggested are Congo red & Bismarck brown.

• Identification by Infrared Spectroscopy

Cellulose, subcutaneous tissue : fibro-adipose tissue, acute inflammation (H&E)

Cellulose, birefringent under polarized light (H&E)

Sirius red (a modified cotton dye)

For connective tissue For amyloid

CellulosePAS : GMS

IR Spectroscopy: Characteristic of cellulose

Adjacent tissue

Birefringent material

Gauze (cellulose)

Wood splinter (H&E)

CELLULOSE H&E : Polarized

CELLULOSE

Sirius red GMS PAS

NYLON

• Sutures, (instruments, wound dressings)• Circular, elliptical or cylindrical structures• Colorless to brownish in H&E sections• Brightly birefringent under polarized light• Identification by infrared spectroscopy,

(Because of C-N linkage, IR spectrum is close to tissue protein, but peaks narrower; area examined needs optical localization)

Subcutaneous Nylon suture granuloma

Nylon suture granuloma, H&E, (polarized right)

Nylon infrared spectroscopy

Nylon Raman Microspectroscopy

(two excitation wavelengths)

Nylon suture granuloma H&E

Nylon

Silicone

Silicone infrared spectroscopy (I.R.)

Polypropylene

• Non-absorbable meshes for hernia repair, (Marlex®, Prolene®, Surgipro®)

• Emergency abdominal wall reconstruction• Non-absorbable sutures; Prolene®• Colorless rounded structures on H&E• Brightly birefringent under polarized light• Will stain with 72 hour Oil red O• Identification by infrared spectroscopy (IR)

Polypropylene mesh, inguinal hernia repair, (H&E)

Polypropylene mesh H&E; polarized

Polypropylene mesh H&E; polarized

Polypropylene mesh 72hr. Oil red O, polarized (right)

Polypropylene infrared spectroscopy

Polypropylene

Birefringent material

Poly-L-lactic acid and Polyglycolic acid copolymers

Poly-L-lactic acid and polyglycolic acid copolymers (PLLA/PGA) have been investigated as resorbable surgical fixation devices, (and are used in resorbable sutures).

Case example: 8 months prior to biopsy, pt. underwent mandibular surgery with reconstruction using PLLA/PGA screws & plates. By light microscopy, weakly eosinophilic to grey irregularly shaped fragments of material with variable birefringence were seen.

Mandibular biopsy, PLLA/PGA, 8 months post-op: H&E

Mandibular biopsy, PLLA/PGA, 8 months post-op ; H&E Polarized light

Infrared Spectra: (I.R.) mandibular biopsy at 8 months post-op

PLLA/PGA

PLLA/PGA screw Raman spectra

500

1000

1500

2000

2500

3000

Int

10000

20000

30000

40000

50000

60000

70000

Int

500 1000 1500 2000 2500 3000 3500 Raman shift (cm-1)

Mandible biopsy

Plastic material

Polylactic acid - Polyglycolic acid screw

Specimen X-ray: Mandibular biopsy;

25 months post-operatively

Remodelledbone in former PLLA/PGAscrew hole

Bone biopsy : 25 months

post-operatively:

H&E

Remodelledbone in former

PLLA/PGA screw hole

Dental amalgam

• Dental amalgam is a multiphasic material containing silver (Ag), tin (Sn), mercury (Hg), and lesser amounts of copper (Cu).

• Incidental tattooing of buccal mucosa may occur during dental procedures.

• Prolonged tissue implantation leads to loss of mercury, (and tin), and persistence of silver with sulfur (S) and selenium (Se) deposition.

Amalgam Tattoo

• Black/brown mucosal discoloration• May be of clinical concern (r/o melanoma)• In H&E sections, black granular material in

submucosa, (not removed by melanin bleach)• Identification by SEM/EDXA

Dental amalgam tattoo (Photograph courtesy of the Department of Oral & Maxillofacial Pathology, AFIP)

Dental amalgam tattoo, buccal biopsy, (H&E)

Dental amalgam tattoo, buccal biopsy (H&E)

Amalgam tattoo melanin bleach

Amalgam tattoo SEM/EDXA(glass slide) silver, sulfur and selenium

Amalgam tattoo SEM/EDXABackground (glass slide), carbon, oxygen,

sodium, silicon, calcium

Acrylic polyamide plastic embolization material

• Embolization microspheres have been developed for tumor embolization and treatment of vascular malformations.

• Uterine artery embolization for treatment of fibroids• Several materials have been used, (polyvinyl alcohol,

collagen, dextran, and trisacryl-co-polymer crosslinked with gelatin).

• The latter has the IR spectral characteristics of acrylic polyamide plastic.

Acrylic polyamide plastic embolization product

• Acrylic polyamide plastic embolization particles, appear as rounded often folded circular eosinophilic to weakly basophilic objects usually in an intravascular location.

• May have “Venetian blind effect”• Diameter depends on product used, and plane of

section, but in our tissue examples <700µm• Partial birefringence when stained with Sirius red,

but not in other stained sections• Oil red O, AMP, PAS negative• Mucicarmine and Sirius red positive

Intravascular acrylic polyamide plastic, (uterus), (H&E)

Acrylic polyamide plastic with “foreign body” giant cell reaction (H&E)

Intravascular acrylic polyamide plastric, uterus, (Movat)

Acrylic polyamide plastic with “Venetian blind” effect ? Pseudo-parasite (H&E)

Acrylic polyamide plastic with “Venetian blind” effect, (Trichrome)

Acrylic polyamide plastic embolization microspheres, SEM

SEM of authentic example of trisacryl-polymer-gelatin embolization product selected for IR

spectroscopy comparison

100µm

Acrylic polyamide plastic (embolization microsphere) infrared spectroscopy

Trisacryl-co-polymer with gelatin

Intravascularmaterial

Modern Pathology (2006) 19, 922-930

Barium sulfate

• Radiologic contrast medium, especially for G.I. tract imaging

• Aspiration into lung as a complication of upper G.I. studies

• Birefringent granular crystalline material may appear pale brownish/green in H&E-stained sections, often within macrophages

• (“Micropulverized BaSO4” non-birefringent)• Identification by SEM/EDXA

Barium sulfate aspiration (longstanding),canine lung, (autopsy), (H&E)

Barium sulfate aspiration, canine lung, (H&E), polarized (right)

Radiohistology as a New Diagnostic Method for Barium Granuloma

• De Mascarel A, Merlio JP, Goussot JF, Coindre JM. Arch. Pathol. Lab Med. 1988;112:634-636.

• 4 cases lower G.I. barium granulomas• Hx.s of barium enema 3 weeks to 20

months before bx.• Gastroenterologists suspected carcinoma

in 2 of 4

Barium sulfate “Radiohistology”

Barium sulfate: Scanning electron microscopy/energy dispersive X-Ray analysis (SEM/EDXA)

Barium sulfate: Infrared spectroscopy (IR)

0

5

10

15

20

25

30

35

40%

Ref

lect

ance

40

50

60

70

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90

100

110

%R

efle

ctan

ce

10001500200025003000 3500

Wavenumbers (cm-1)

Lung tissue – foreign material

(canine)

Barium sulfate - reference

Tissue protein

Argyria

• “A permanent ashen-gray discoloration of the skin, conjunctiva, and internal organs that results from long-continued use of silver salts” Dorland’s Illustrated Medical Dictionary 28th Edition

• A rare dermatosis due to avoidance of silver-containing medicinals and decreased occupational exposure.

• New cases do still arise• Attempts at chelation Rx. generally unsuccessful• May be localized, (e.g. site of occupational injury)

Argyria (cont.)

• Most prominent clinical manifestation cosmetic• Skin pigmentation is due to silver deposits and

stimulation of melanocytes.• In H&E sections, black grains with preferential

deposition along basement membranes, elastic fibers, (and in macrophages within organs).

• Identification by SEM/EDXA • Often sulfur and selenium collocate with silver.

Argyria, skin punch biopsy, H&E

Argyria; dermo-epidermal junction (H&E)

Argyria; Eccrine gland, (H&E)

Argyria; Subcutaneous blood vessel (H&E)

Argyria; Sebaceous gland (SEM fields brown) (H&E)

Argyria; SEM on glass slide

12 µm

Argyria: SEM/EDXA glass slide

Argyria; SEM/EDXA silver granule with sulfur on glass slide

Ag

Argyria: Scanning electron microscopy carbon disc

5 microns

Argyria: SEM/EDXA demonstrates presence of silver (Ag), sulfur (S) and selenium (Se).

5 mircons

Argyria: SEM/EDXA mapping for sulfur (S), silver (Ag), and selenium (Se).

Polystyrene sulfonate

• Sodium polystyrene sulfonate (Kayexalate)• Cation-exchange resin, prepared in the sodium

phase• Sodium ions released in exchange for

potassium ions mainly in the colon• Used in the Rx. of hyperkalemia• Admin. orally (suspension) or by enema

Polystyrene sulfonate [cont.]

• In H&E sections; basophilic sheets with linear markings

• Very weakly birefringent• In a study of pediatric cases material was

present within air spaces without eliciting an inflammatory response

• Identification by infrared spectroscopy

Polystyrene sulfonate, pediatric lung, aluminized slide, (unstained)

for IR spectroscopy

Polystyrene sulfonate infrared spectra

10

20

30

40

50

60

%T

2

4

6

8

10

%T

1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)

LUNG BIOPSY

POLYSTYRENE

SULFONATE

Polystyrene sulfonate Raman spectra (dispersive and FT)

Polystyrene sulfonate: Adult Lung: (H&E)

Polystyrene sulfonate within giant cell : Adult lung: H&E

CROSPOVIDONE (poly[N-vinyl-2-pyrrolidone])

• Crospovidone is a form of polyvinylpyrrolidone (PVP) formed by “pop-corn polymerization”.

• Used in oral medications as a disintegrant• Basophilic, “coral-like”, non-birefringent

particles on H&E• Not widely metabolized

CROSPOVIDONE [cont.]

• PAS negative, Mucicarmine positiveMucicarmine positive• Stains with Congo Red• Pale brown to grey with GMS• Alcian blue stains red, blue in giant cells• Movat yellow-orange, blue-green in giant cells• Identification by infrared spectroscopy =

Polyvinylpyrrolidone (PVP)

Polyvinylpyrrolidone Pathology(Non-Crospovidone)

• Subcutaneous pseudosarcomatous PVP granuloma

• Thesaurosis (hair sprayer’s lung)• Mucicarminophilic histiocytosis•• Source of errorSource of error signet ring cell gastric

adenocarcinoma

Pulmonary vessel, with “foreign-body” giant cell reaction to cellulose (A) and crospovidone (B&C) (H&E)

Infrared spectra

Crospovidone in tissue

Crospovidone in tissue

Cellulose in tissue

Cellulose, (birefringent) and crospovidone (non-birefringent) Lung, (H&E), polarized (left)

Modern Pathology 2003;16 (4): 286-292.

Crospovidone powder, H&E (x480)

Crospovidone powder: Infrared spectrum

Crospovidone powder; PASD (x100)

Crospovidone, lung, intravascular, PASD (x100)

Crospovidone powder ; Mucicarmine, (x100)

Crospovidone, lung; Mucicarmine (x50)

Crospovidone & cellulose, lung,polarized : GMS (x57)

Pulmonary pathology of I.V. administration of oral tablet suspensions

•• Pulmonary Pulmonary angiothromboticangiothrombotic granulomatosisgranulomatosiscaused by talc, cornstarch and/or microcrystalline cellulose has been widely reported.

• The development of subsequent fatal pulmonary hypertension and cor pulmonale has been emphasized.

• Ordinary illicit heroin reportedly doesn’t contain enough insoluble crystalline debris to cause extensive pulmonary angiothrombosis.

TALC (MgSiO4)

• Pleurodesis, talcosis, operative sites, inactive ingredient in medications, IVDU

• Micaceous, colorless and birefringent• Oil red O stain may be positive• Identification SEM/EDXA as containing

magnesium, silicon and oxygen• Infrared spectroscopy characteristic

Birefringent pieces of talc (MgSi04) in breast tissue of implant patient

Talc infrared spectroscopy

Talc, Pleura, (H&E)

Talc, pleura, (H&E), polarized (right)

Talc, pleura, PAS, polarized (right)

Talc, Pleura, (SEM)

Talc, (MgSiO4), pleuraSEM : EDXA

Talc energy dispersive X-ray analysis (EDXA) elemental maps

OxygenCarbon

Magnesium Silicon

Summary

• Many types of medical “foreign bodies” may be present in histopathology specimens.

• Familiarity with these materials may help pathologists avoid possible sources of diagnostic error.

• Adequate clinical history is extremely helpful.• Close collaboration with expert spectroscopists and

toxicologists, helps characterize many materials .• Accurate characterization can benefit patents,

clinicians, regulatory agencies, and other interested parties.

Acknowledgements

• VF Kalasinsky, Ph.D.• The late FB Johnson, M.D.• FG Mullick, M.D., Sc.D.• JF Tomashefski, M.D.• CS Specht M.D., LA Murakata, M.D.• Mr. A. Shirley, Mr. D. Landry• AFIP Staff, colleagues, and contributors