9.2 Casefinding Sources: Pathology, Cytology, Disease Index & Logs

9.2 Casefinding Sources: Pathology, Cytology, Disease Index & Logs

To achieve complete case ascertainment, a cancer registry must build a comprehensive, multi-layered casefinding network. Relying on a single clinical feed—such as surgical pathology—guarantees significant under-reporting. Many hematologic malignancies, advanced unbiopsied neoplasms, outpatient radiotherapy cases, and benign central nervous system tumors never generate an inpatient surgical pathology specimen. Oncology Data Specialists (ODS-C) must understand the diagnostic characteristics and operational screening protocols across all facility data streams.

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Anatomic Pathology & Cytology: The Surveillance Cornerstone

Anatomic pathology and cytology reports are the highest-yield casefinding source for solid tumors. Every tissue specimen processed through the hospital laboratory must pass through the registry casefinding filter.

1. Surgical Pathology Specimens

• Biopsies: Excisional, incisional, punch, core needle, and endoscopic mucosal biopsies.
• Resection Specimens: Complete organ resections (e.g., colectomies, mastectomies, prostatectomies, pneumonectomies) providing definitive pathological T and N categories and surgical margin status.
• Frozen Section Consultations: Intraoperative pathological assessments that immediately flag provisional malignancies.

2. Bone Marrow Aspirates & Core Biopsies

Bone marrow documentation is essential for ascertaining hematologic and lymphoid neoplasms. These include acute leukemias (AML, ALL), chronic leukemias (CML, CLL), multiple myeloma, myelodysplastic syndromes (MDS), and myeloproliferative neoplasms (MPN). Because these patients are frequently managed in outpatient hematology clinics without undergoing solid organ resection, reviewing bone marrow logs is vital to prevent severe ascertainment gaps.

3. Cytopathology & Fine-Needle Aspirations (FNA)

Cytology specimens evaluate exfoliated cells or aspirated fluid without intact tissue architecture:

• Fine-Needle Aspirations (FNA): Thyroid nodules, palpable breast masses, salivary gland lesions, and suspicious lymph nodes.
• Brushings & Washings: Bronchial brushings, bronchoalveolar lavage (BAL), esophageal brushings, and biliary duct brushings obtained during endoscopic retrograde cholangiopancreatography (ERCP).
• Body Fluid Cytology: Pleural fluid, peritoneal/ascitic fluid, pericardial fluid, and cerebrospinal fluid (CSF). Positive cytology in pleural or peritoneal fluid frequently establishes distant metastatic disease (Stage IV / M1).

4. Autopsy Reports

Autopsy examinations capture unsuspected occult malignancies, confirm metastatic extent in ambiguous clinical deaths, and identify cancer cases that were completely undiagnosed during life. Cases identified solely at autopsy (where cancer was never suspected prior to death) are designated as Class of Case 38.

5. Electronic Pathology (e-Path) Screening Logic

Modern facilities implement automated e-Path interfaces that parse electronic laboratory feeds using natural language processing (NLP), SNOMED morphology codes, or diagnostic regex dictionaries. The algorithm automatically flags diagnostic keywords such as carcinoma, sarcoma, melanoma, lymphoma, blast, neoplasm, in situ, and high-grade intraepithelial.

Quality Control Alert: While e-Path drastically accelerates casefinding, it cannot replace human review. Automated engines generate frequent false positives (e.g., "negative for carcinoma" or "margins free of neoplasm") and false negatives (e.g., obscure histologic variants). The ODS must independently review each flagged record before clearing it to the abstracting queue.

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Health Information Management (HIM) Disease Index Screening

The HIM Disease Index is an electronic master ledger generated from patient discharge and billing records, indexed by ICD-10-CM diagnostic codes. It serves as the primary safety net for catching cases that bypass the hospital pathology laboratory (such as patients biopsied at outside facilities, clinically diagnosed tumors, or patients admitted solely for systemic therapy).

┌─────────────────────────────────────────────────────────────────────────┐
│               ICD-10-CM NEOPLASM SCREENING RANGES                       │
└───────────────────────────────────┬─────────────────────────────────────┘
                                    │
  ┌─────────────────┬───────────────┴───────────────┬─────────────────┐
  ▼                 ▼                               ▼                 ▼
C00 – C96         D00 – D09                       D37 – D48         D49
Malignant         Carcinoma In Situ               Uncertain         Unspecified
Neoplasms         Neoplasms                       Behavior          Behavior
(All Primary      (Oral, GI, Resp,                (Must Screen      (Provisional
 & Secondary)      Breast, Bladder)                GIST, MDS, MPN)   Diagnoses)

Core ICD-10-CM Neoplasm Code Categories to Screen

1. C00 – C96 (Malignant Neoplasms): Encompasses all primary invasive malignancies, secondary metastatic sites, and hematologic cancers. Every single C-code encounter must be screened.
2. D00 – D09 (In Situ Neoplasms): Encompasses carcinoma in situ of digestive organs, middle ear/respiratory system, breast, eye, and bladder. (Note: Cervical in situ D06 is non-reportable per national standards).
3. D37 – D48 (Neoplasms of Uncertain Behavior): Crucial screening category. Contains conditions that standard clinical coders categorize as uncertain, but which registry standards classify as reportable. This includes myelodysplastic syndromes (MDS) and chronic myeloproliferative neoplasms (MPN), which ICD-O codes as malignant (/3), and malignant GIST and neuroendocrine tumors that clinical coders sometimes index as uncertain behavior. Borderline ovarian tumors (/1) are not reportable; screen these codes, but accession only the conditions registry standards define as reportable.
4. D49 (Neoplasms of Unspecified Behavior): Identifies provisional clinical diagnoses where histology has not yet been obtained or documented. Screening D49 ensures clinically diagnosed tumors do not slip through registry surveillance.
5. Mandated Non-Malignant Brain & CNS Codes: Under Public Law 107-260, non-malignant brain and central nervous system tumors are reportable. Registrars must screen:
   • D32.0 – D32.9: Benign neoplasm of meninges (cerebral, spinal, unspecified).
   • D33.0 – D33.9: Benign neoplasm of brain and other parts of central nervous system (supratentorial, infratentorial, cranial nerves).
   • D35.2: Benign neoplasm of pituitary gland.
   • D35.3: Benign neoplasm of craniopharyngeal duct.
   • D35.4: Benign neoplasm of pineal gland.
6. Secondary & Encounter Codes:
   • Z85.0 – Z85.9: Personal history of malignant neoplasm (screens for patients receiving subsequent care or developing second primaries).
   • Z51.0: Encounter for antineoplastic radiation therapy.
   • Z51.11: Encounter for antineoplastic chemotherapy.
   • Z51.12: Encounter for antineoplastic immunotherapy.

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Diagnostic Radiology & Nuclear Medicine Casefinding

Radiology and nuclear medicine reports identify patients with advanced, deep-seated, or clinically diagnosed neoplasms who never undergo surgical resection due to poor performance status, anatomical risk, or rapid decline.

Key Imaging Modalities Screened

• Computed Tomography (CT) & Magnetic Resonance Imaging (MRI): Screened for definitive or suspicious masses of the brain, lung, pancreas, liver, and kidneys.
• Positron Emission Tomography (PET/CT): Highly sensitive for hypermetabolic neoplastic lesions, regional lymph node involvement, and occult distant metastases.
• Interventional Radiology (IR) Biopsy Logs: Tracks image-guided percutaneous biopsies (e.g., CT-guided lung core, ultrasound-guided liver core, fluoroscopic bone biopsy). These procedures are frequently performed in outpatient radiology suites and may fail to route to main surgical operating room ledgers.

Breast Imaging: BI-RADS Assessment Categories

Diagnostic mammography and breast ultrasound reports utilize the standardized Breast Imaging Reporting and Data System (BI-RADS) established by the American College of Radiology (ACR). Registrars must apply strict screening actions based on the assigned BI-RADS category:

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Clinical Logs, Outpatient Clinics & Endoscopy Services

A resilient casefinding network incorporates non-pathology clinical and ambulatory service points across the healthcare system:

                    ┌─────────────────────────────────────────┐
                    │       MULTIDISCIPLINARY CASEFINDING     │
                    │           CLINICAL INTAKE MATRIX        │
                    └────────────────────┬────────────────────┘
                                         │
     ┌───────────────────┬───────────────┴───────────────┬───────────────────┐
     ▼                   ▼                               ▼                   ▼
┌──────────────┐  ┌──────────────┐                ┌──────────────┐  ┌──────────────┐
│ Radiation    │  │ Medical      │                │ Dermatology  │  │ Endoscopy &  │
│ Oncology     │  │ Oncology     │                │ & Outpatient │  │ Ambulatory   │
│ Schedules    │  │ Infusion Logs│                │ Biopsy Logs  │  │ Surgical Logs│
└──────────────┘  └──────────────┘                └──────────────┘  └──────────────┘

1. Radiation Oncology Treatment Planning Systems: Software systems such as ARIA or MOSAIQ track simulation schedules, treatment planning prescriptions, and linear accelerator delivery logs. This is a critical source for capturing analytic cases that were diagnosed and resected at an external hospital but referred to the reporting facility for first-course adjuvant external beam radiotherapy.
2. Medical Oncology & Chemotherapy Infusion Ledgers: Pharmacy and infusion clinic scheduling logs capture patients receiving outpatient intravenous chemotherapy, targeted antibody therapy, or immunotherapy. This source is vital for ascertaining patients with metastatic disease managed non-operatively.
3. Dermatology & Ambulatory Biopsy Logs: Dermatologists and minor procedure suites frequently utilize private external commercial laboratories (e.g., Quest, Labcorp, Dermpath) rather than the hospital's in-house laboratory. Regularly auditing dermatology logs ensures the capture of invasive cutaneous melanomas, Merkel cell carcinomas, and genital skin carcinomas.
4. Endoscopy & Surgical Suite Registers: Procedure schedules from endoscopy suites (bronchoscopy, upper endoscopy, colonoscopy, cystoscopy, EUS) identify patients with visualized mucosal tumors where biopsies were sent to outside laboratories or where preliminary optical diagnosis warrants suspense tracking.

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Comparison of Core Casefinding Sources

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Practice Scenario & Exam Pitfalls

Clinical Practice Scenario

An 84-year-old female presents to the outpatient imaging center with a dense breast mass. Diagnostic mammography demonstrates an irregular, spicular mass with clustered pleomorphic microcalcifications measuring 3.5 cm, formally categorized as BI-RADS 5 (Highly Suggestive of Malignancy). The patient has advanced dementia, and her healthcare surrogate declines core needle biopsy or surgical excision. The patient is placed on oral letrozole by her geriatrician and discharged to memory care. The cancer registry clerk asks whether this case is reportable without a pathology report.

ODS Regulatory Analysis: STORE 2025 states that BI-RADS, PI-RADS and LI-RADS categories alone are not reportable for CoC; they become reportable when confirmed by a biopsy or a physician's statement. The BI-RADS 5 report by itself does not make the case reportable. The ODS checks the geriatrician's note: if the physician documents a clinical diagnosis of breast cancer (for example, "presumed breast carcinoma; starting letrozole"), the case is reportable without microscopic confirmation (Diagnostic Confirmation code 7, radiography and other imaging techniques without microscopic confirmation), and the date of diagnosis is the date of that definitive physician statement. If no physician ever states a diagnosis of cancer, the case stays in suspense.

Core Exam Pitfalls to Avoid

• Pitfall 1: Screening only C-codes in the HIM disease index. Registrars who screen only C00–C96 completely miss in situ lesions (D00–D09), benign brain and CNS tumors (D32, D33, D35.2–D35.4), and borderline conditions like GIST or MDS (D37–D48).
• Pitfall 2: Discarding BI-RADS 4 mammography reports immediately. BI-RADS 4 indicates a suspicious lesion requiring biopsy. These cases must be entered into the Suspense File to track the forthcoming biopsy results, rather than being discarded.
• Pitfall 3: Assuming all pathology is processed in the main hospital lab. Ambulatory surgery, endoscopy, and dermatology clinics often route specimens to commercial off-site pathology laboratories. Auditing facility procedural logs ensures these outsourced specimens are captured.