LINGUISTIC INVENTORY OF THE
JOHNS HOPKINS SURGICAL PATHOLOGY DATABASE.

G. William Moore, MD, PhD [1,2,3],
Robert E. Miller, MD [1].
From: Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, MD [1].
Department of Pathology, Baltimore VA Maryland Health Care System [2], Baltimore, MD [2].
Department of Pathology, University of Maryland School of Medicine, Baltimore, MD [3].

U. S. Government Work, published in:
the Johns Hopkins Autopsy Resource,
www.netautopsy.org



TABLE OF CONTENTS.


1. ABSTRACT.
2. PATIENT DEMOGRAPHICS.
3. DISTRIBUTION OF ORGAN SYSTEMS.
4. RAW WORD COUNTS.
5. UMLS PART-OF-SPEECH LIST.
6. HISTORY OF COMPUTATIONAL LINGUISTICS.
7. DISCOVERY METHODS.
8. BACKUS NAUR PARSING MODEL.
9. FREQUENCY DISTRIBUTION OF BARRIER WORS.
10. FREQUENCY DISTRIBUTION OF COLLOCATIONS.
11. ZIPF GRAMMAR.
12. ZIPF DISTRIBUTION OF BACKUS NAUR FORMS.
13. CONCLUSION.
14. REFERENCES.



1. ABSTRACT.

LINGUISTIC INVENTORY OF THE
JOHNS HOPKINS SURGICAL PATHOLOGY DATABASE.


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G. William Moore, MD, PhD [1,2,3],
Robert E. Miller, MD [1].
From: Departments of Pathology, The Johns Hopkins Medical Institutions [1], Baltimore, MD.
Baltimore VA Maryland Health Care System [2], Baltimore, MD.
University of Maryland School of Medicine, Baltimore, MD [3].

Background. There is increasing interest in encoding free-text surgical pathology reports for data-mining applications, including tissue-archival and epidemiologic studies. A useful first step is to conduct a linguistic inventory of the database.

Design. The linguistic content of the Johns Hopkins Surgical Pathology (JHSP) database was tabulated by machine translation and natural language processing methods. The database spans sixteen years, from March, 1984, to the present, with patient identifiers, accession and release dates, a free-text brief clinical history, and a free-text surgical pathology diagnosis.

Results. On June 1, 2000, the JHSP database contained 159,071 patients with surgical pathology cases, 361,957 surgical pathology cases, and 694,443 surgical pathology specimens. Age/sex demographics were complete for 99.3% of patients, including 60.1% females and 39.2% males. Organ-systems in the database included: gastrointestinal, 28.7%; lymphoreticular, 15.1%; gynecologic, 14.0%; bone, 7.1%; breast, 5.8%. There were 9,004,337 words, 27,139 distinct words and 15,589 multiply-occurring words. Words ranged in frequency from 222,175 occurrences of the word 'and' to the 11,550 singly-occurring words, with an estimated 0.1% misspelling rate. Common parts-of-speech included: nouns, 4,458,102; adjectives, 2,187,808; prepositions, 709,617; noun-or-verbs, 275,683; conjunctions, 262,589. Common multiple word terms (collocations) included: chronic inflammation, 38,401; lymph nodes, 20,328; soft tissue, 16,104; bone marrow, 14,456. Among correctly spelled words, there were 8,406,088 (93.5%) exact or approximate matches to UMLS concept unique identifiers. In a pilot study, 82.8% of 2,302,366 sentences could be parsed, using the Backus-Naur linguistic model.

Conclusion. Results suggest that short sentences in free-text surgical pathology reports with a low misspelling rate can be parsed and pointed to UMLS codes, for pathology informatics studies.



2. PATIENT DEMOGRAPHICS.


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  • JUNE 1, 2000: DEMOGRAPHIC AND LINGUISTIC CONTENT
    OF JOHNS HOPKINS SURGICAL PATHOLOGY (JH-SP) DATABASE.
                      FEMALE       MALE    UNKNOWN     TOTAL  % PATIENTS
        0-9 years      3,763      5,906         13     9,682        6.1%
      10-19 years      6,409      2,841          7     9,257        5.8%
      20-29 years     17,318      3,341         16    20,675       13.0%
      30-39 years     18,743      5,618         13    24,374       15.3%
      40-49 years     15,149      7,405         26    22,580       14.2%
      50-59 years     12,269     11,057         18    23,344       14.7%
      60-69 years     10,873     14,501         26    25,400       16.0%
      70-79 years      8,198      9,377         14    17,589       11.1%
      80-89 years      2,650      2,239          9     4,898        3.1%
      90-99 years        225        121          0       346        0.2%
    100-109 years          5          2          0         7        0.0%
      Unknown age                              919       919        0.6%
            Total     95,602     62,408      1,061   159,071      100.1%
                       60.1%      39.2%       0.7%
    




    3. DISTRIBUTION OF ORGAN SYSTEMS.


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          ORGAN-SYSTEMS REPRESENTED AMONG 361,957 CASES:
         ORGAN SYSTEM        CASES  PERCENT
     Gastrointestinal      103,819    28.7%
      Lymphoreticular       54,597    15.1%
          Gynecologic       50,579    14.0%
                 Bone       25,578     7.1%
               Breast       20,939     5.8%
         Dermatologic       20,747     5.7%
            Obstetric       19,167     5.3%
        Genitourinary       18,916     5.2%
                Blood       17,787     4.9%
               Marrow       16,576     4.6%
                Heart       14,490     4.0%
                 Lung        8,015     2.2%
                  CNS        6,320     1.7%
        Neuromuscular        4,789     1.3%
            Endocrine        3,288     0.9%
    




    4. RAW WORD COUNTS.


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  • 9,004,337 WORDS.

  • 27,139 DISTINCT WORDS.

  • 11,550 SINGLY OCCURRING WORDS (HAPAX LEGOMENA).

  • 15,589 MULTIPLY OCCURRING WORDS.

  • 222,175 OCCURRENCES OF WORD 'AND'.

  • TO THE 11,550 SINGLY OCCURRING WORDS.

  • MISSPELLING RATE OF 0.1% = 11,550/9,004,337.




  • 5. UMLS PART-OF-SPEECH LIST.


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  • EACH WORD ASSIGNED TO SYNTACTIC CATEGORY OR PART-OF-SPEECH:
  • A=Adjective;
  • B=adverB;
  • C=Conjunction (and, or, ...);
  • D=Determiner (the, this, ...);
  • H=Helpingverb;
  • I=Interrogative (who, which, why, how,..., including complementizers);
  • N=Noun;
  • P=Preposition (at, by, to, for, from,...);
  • R=pRonoun (he, she, it, we, they,...);
  • V=Verb.
    POS NAME	POS LETTER	POS DECIMAL	NO. OCCURRENCES
    Adjective	A		1		2,187,808
    adverB		B		2		204,278
    Conjunction	C		16		262,589
    Determiner	D		32		164,435
    Helpingverb	H		4		174,048
    Interrogative	I		8		18,338
    Noun		N		128		4,458,102
    Preposition	P		256		709,617
    pRonoun		R		512		11,824
    mainVerb	V		1024		21,205
    

    Adj or Adv A|B 3 4,586 Adj or Noun A|N 129 115,075 Adj, Noun, Vb A|N|V 1153 114,981 Adj or Verb A|V 1025 259,917 Dtrmr or Int D|I 40 10,263 Noun or Verb N|V 1152 275,683 Unassigned 11,588
    TOTAL 9,004,337




  • 6. HISTORY OF COMPUTATIONAL LINGUISTICS.


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  • NOAM CHOMSKY'S THESIS ON THE LINGUISTICS OF HEBREW.

  • ALL HUMAN LANGUAGES MAY BE REPRESENTED AS SET OF PRODUCTION RULES.

  • BACKUS NAUR FORM (BNF) ORIGINALLY USED TO DESCRIBE COMPUTER LANGUAGES.

  • SCANT ATTENTION TO QUANTITATIVE AND STATISTICAL BEHAVIOR TECHNICAL PROSE.

  • SURGICAL PATHOLOGY FREE-TEXT: RESTRICTED VOCABULARY; INTENTIONALLY UNAMBIGUOUS.




  • 7. DISCOVERY METHODS.


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  • ZIPF'S LAW: HIGH-FREQUENCY WORDS IN LARGE FREE-TEXT CORPUS ARE EXTREMELY COMMON.

  • WORD-RANK (r) INVERSELY PROPORTIONAL TO WORD-FREQUENCY (f): FOR CONSTANT, k, r = k/f.

  • APPROXIMATELY ONE HUNDRED BARRIER WORDS: OVER HALF OF ALL WORD-OCCURRENCES.

  • BARRIER WORDS OR STOP WORDS: COMMONLY-OCCURRING, INCLUDING ARTICLES, CONJUNCTIONS, INTERROGATIVES, COMPLEMENTIZERS, INTERROGATIVES, PREPOSITIONS, PRONOUNS, AUXILIARY VERBS.

  • BARRIER WORD METHOD: BARRIER WORDS ARE SEPARATORS, OR BARRIERS, BETWEEN MULTIPLE-WORD MEDICAL TERMS.

  • MULTIPLE-WORD TERMS, OR COLLOCATIONS, BOUNDED ON EITHER SIDE BY BARRIER WORDS.

  • TERMINAL ILEUM , CECUM , APPENDIX and COLON ( RIGHT HEMICOLECTOMY ) ; MODERATELY DIFFERENTIATED COLONIC ADENOCARCINOMA , with extension through MUSCULARIS PROPRIA into PERICOLIC SOFT TISSUE , and with involvement of PERINEURAL SPACES . TUBULOVILLOUS ADENOMA and associated VASCULAR MALFORMATION in the TRANSVERSE COLON ; TUBULAR ADENOMA in the DESCENDING COLON . recent COLOSTOMY SITE with SUBMUCOSAL FIBROSIS and INFLAMED GRANULATION TISSUE in the SEROSA . multiple ADHESIONS and SEROSAL ABSCESSES with GRANULATION TISSUE , FOREIGN BODY GIANT CELLS , SCARRING , focal OSSIFICATION , and FAT NECROSIS . ISCHEMIC BOWEL DISEASE diffusely involving ILEAL MUCOSA , with focal TRANSMURAL NECROSIS and ACUTE INFLAMMATION .


  • ZIPF'S LAW FOR GRAMMAR: BACKUS NAUR FORM AKIN TO WORDS IN TEXT.

  • CANONICAL FORM: PREFERRED NOTATION, ENCAPSULATES ALL EQUIVALENT FORMS OF SAME CONCEPT.

  • ARBITRARY LEVELS OF RECURSION OF XML TAGS:
      <code-section>
        <c> ... <c> ... <c > ... </c></c></c>
      </code-section>
    


  • INTEGRATED CLINICAL DATA WAREHOUSE:
      <patient>
        <case>
          <specimen>
            <report-section>
              <code-section>
                <c> ... <c> ... < <c> ... </c></c></c>
              </code-section>
            </report-section>
          </specimen>
        </case>
      </patient>
    




  • 8. BACKUS NAUR PARSING MODEL.


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  •   1. [] ==> [Nx]  
      2. [Nx] ==> [N]     Example:  HEMANGIOMA.
      3. [Nx] ==> [AN]    Example:  ACTINIC KERATOSIS.
      4. [Nx] ==> [NPN]   Example:  ADENOCARCINOMA OF COLON.
    


  • REVERSE BACKUS-NAUR-FORM PARSING: PARSER BEGINS WITH THE MORE COMPLEX EXPRESSION AND WORKS BACKWARD TO SIMPLER EXPRESSION.




  • 9. FREQUENCY DISTRIBUTION OF BARRIER WORDS.


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    RANK	FREQUENCY   BARRIER WORD
       1      222,175   and
       2      196,153   of
       3      189,799   with
       4      107,039   for
       5      104,067   the
       6       82,104   note
       7       80,740   in
       8       78,549   right
       9       77,885   left
      10       70,923   is
      11       70,261   see
      12       67,917   are
      13       53,071   mild
      14       49,987   identified
      15       47,804   to
      16       41,467   consistent
      17       39,792   this
      18       30,352   present
      19       27,189   seen
      20       25,371   at
      21       25,097   there
      22       24,657   on
      23       24,284   or
      24       23,021   be
      25       21,243   associated
      26       19,515   was
      27       18,376   one
      28       16,122   but
      29       16,057   case
      30       16,057   from
      31       16,036   these
      32       15,672   show
      33       15,396   separate
      34       15,135   by
      35       13,776   as
      36       13,730   an
      37       13,542   has
      38       13,074   only
      39       12,615   shows
      40       11,735   portion
      41       11,487   involving
      42       10,803   two
      43       10,718   which
      44       10,448   features
      45       10,263   that
      46       10,119   low
      47       10,097   three
    




    10. FREQUENCY DISTRIBUTION
    OF MULTIPLE-WORD TERMS (COLLOCATIONS).


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    RANK	FREQUENCY   COLLOCATION
       1       38,401   chronic inflammation
       2       20,328   lymph nodes
       3       18,428   diff quik
       4       16,104   soft tissue
       5       14,456   bone marrow
       6       13,104   non diagnostic
       7       13,021   diagnostic findings
       8       13,004   non diagnostic findings
       9       12,868   helicobacter pylori
      10       12,328   crypt distortion
      11       12,316   lymph node
      12       12,292   quik stain
      13       12,284   diff quik stain
      14       11,080   mild chronic
      15       10,229   epithelial changes
      16       10,004   fibroadipose tissue
      17        9,967   non specific
      18        9,052   left breast
      19        8,893   inflammatory disease
      20        8,741   gastroesophageal reflux
      21        8,234   gleason grade
      22        7,994   squamous metaplasia
      23        7,797   tubular adenoma
      24        7,237   reactive epithelial
      25        6,944   reactive epithelial changes
      26        6,793   active chronic
      27        6,714   granulation tissue
      28        6,634   seminal vesicles
      29        6,312   surgical margins
      30        6,199   lamina propria
      31        6,086   acute rejection
      32        6,038   fallopian tube
      33        6,019   cell metaplasia
      34        5,990   pelvic lymph
      35        5,932   chronic gastritis
      36        5,928   secretory endometrium
      37        5,790   hematopoietic elements
      38        5,648   bile reflux
      39        5,633   chronic cervicitis
      40        5,595   pelvic lymph nodes
      41        5,538   no helicobacter
      42        5,521   no helicobacter pylori
      43        5,422   anti inflammatory
      44        5,418   small bowel
      45        5,379   type indeterminate
      46        5,247   inflammatory drugs
      47        5,243   anti inflammatory drugs
      48        5,183   chronic inflammatory
      49        5,173   hernia sac
      50        5,003   antral mucosa
    




    11. ZIPF GRAMMAR.


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      RANK  FREQUENCY       SENTENCE-PATTERN   EXAMPLE 
         1    423,177                    [N]   hemangioma
         2    106,034                 [N[N]]   liver [needle]
         3     98,958                   [AN]   left foot
         4     85,908                  [N|V]   scar
         5     79,741                 [NN|V]   skin scar
         6     62,042                  [AAN]   epidermal inclusion cyst
         7     50,461                [AN[N]]   laryngeal mass [biopsy]
         8     41,958                  [NCN]   decidua and villi
         9     38,689                [A|NPN]   negative for actinomyces
        10     26,745               [N[NPN]]   cervix [biopsy at 9:00] 
        11     22,097                [N[NN]]   cervix [biopsy 9:00]
        12     21,704                 [NPAN]   skin of left ear
        13     21,102                   [NN]   ear lobe
        14     20,638                  [BAN]   non diagnostic findings
        15     16,864               [AAN[N]]   left chest wall [biopsy]
        16     13,674                 [AAAN]   left axillary soft tissue
        17     12,798              [NCAN[N]]   skin , left flank [biopsy]
        18     12,692                [ANCAN]   soft tissue , inguinal region
        19     12,596               [ANPAAN]   fibrous plaque from left carotid artery
        20     12,507   [N[N]ANCA|VANCA|NPN]   leg [ bka ] old thrombus and calcified atherosclerotic plaque , negative for osteomyelitis 
        21     12,136         [BAANHA|VPAAN]   no helicobacter pylori organisms are identified on diff quik stain
        22     12,097              [AAAN[N]]   left true vocal cord [biopsy]
        23     10,555                [ANPAN]   soft tissue of right wrist 
        24     10,257              [A|NPNCN]   negative for fungi or afb
        25      9,952                  [ANN]   left ear lobe
        26      9,650                [N[AN]]   colon [biopsy left]
        27      9,533               [N[NCN]]   cervix [biopsy , 9:00]
        28      8,732               [ANN[N]]   left ear lobe [biopsy]
        29      8,239                  [NAN]   skin right ear
        30      7,937                    [A]   void
        31      7,550                  [NPN]   biopsy at 9:00
        32      6,862               [NCN[N]]   skin, face [biopsy]
        33      6,675                 [ANPN]   left head of femur
        34      6,121                [NCNCN]   placenta, membranes and cord 
        35      6,111               [AN[NN]]   left breast [core biopsy]
        36      6,096               [N[NPA]]   colon [biopsy of left]
        37      5,728                [N[NA]]   colon [biopsy right] 
        38      5,685              [N[NPAN]]   colon [biopsy of right colon] 
        39      5,650             [ANCAN[N]]   soft tissue , left chest [excision]
        40      5,422          [DNHA|VPDAAN]   this case was shown at the quality assurance conference
    




    12. ZIPF DISTRIBUTION OF BACKUS NAUR FORMS.


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      RANK   FREQUENCY      BNF FORMULA   EXAMPLE
         1     689,478       [N] ==> []   [prostate]
         2     313,234      [AN] ==> []   [actinic keratosis]
         3     117,039     [AAN] ==> []   [hypertrophic actinic keratosis]
         4      86,762     [N|V] ==> []   [scar]
         5      80,127    [NN|V] ==> []   [skin scar]
         6      66,816     [NAN] ==> []   [skin soft tissue]
         7      60,129     [NCN] ==> []   [decidua and villi]
         8      55,728       [AN ==> [N   [actinic KERATOSIS
         9      52,777     [A|N] ==> []   [negative]
        10      47,375      [NN] ==> []   [granulation tissue]
        11      47,139       [A] ==> []   [void]
        12      42,661     [NPN] ==> []   [adenocarcinoma of colon]
        13      36,076    [AAAN] ==> []   [focal bowenoid actinic keratosis]
        14      31,946    [NPAN] ==> []   [skin with actinic keratosis]
        15      25,168     [BAN] ==> []   [focally invasive tumor]
        16      22,761    [NCAN] ==> []   [ulcer and acute inflammation]
        17      22,276     [ANN] ==> []   [exuberant granulation tissue]
        18      16,791       [NN ==> [N   [lung CARCINOMA
        19      15,577    [NAPN] ==> []   [carcinoma metastatic to lung]
        20      13,764     [NNN] ==> []   [liver gallbladder pancreas]
        21      13,212      [AAN ==> [N   [hypertrophic actinic KERATOSIS
        22      12,417     [BAN ==> [BN   [FOCALLY active GASTRITIS
        23      12,053      [NCN ==> [N   [decidua and VILLI
    




    13. CONCLUSION.


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  • ENCODER PARSES COHERENT SURGICAL-PATHOLOGY FREE-TEXT.

  • TARGET: STANDARDIZED CODING LANGUAGE (UMLS), FORMATTED AS XML.

  • PROTOTYPE PARSER: 82.8% SUCCESSFUL PARSES.




  • 14. REFERENCES.


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          8. Moore GW, Miller RE, Hutchins GM.
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          18. U.S. National Library of Medicine.
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    Last Revised: 10/22/2000 by G. William Moore.