When a physician suspects cancer, identifies unusual tissue changes, or encounters a condition that resists clinical explanation, the path forward almost always leads to the pathology laboratory. Pathology converts biological specimens — cells scraped from a surface, fluid drawn from a cavity, tissue removed during a biopsy — into the definitive diagnoses that guide every treatment decision that follows. For patients across Northeast Wisconsin and Michigan’s Upper Peninsula, HSHS St. Mary’s Hospital Medical Center in Green Bay has long provided this service through a fully accredited, round-the-clock laboratory staffed by board-certified pathologists. Understanding how anatomic and clinical pathology function at this institution helps patients and families make sense of what can otherwise feel like an opaque part of their medical care.
What Pathology Does and Why It Comes Before Treatment
Pathology is sometimes described as the discipline every other specialty is waiting on. A surgeon can remove a mass; an oncologist can design a chemotherapy protocol; a radiologist can image a suspicious area. But before any of those specialists can act with confidence, they need the pathologist’s interpretation of what the tissue or cells actually show.
The field divides into two principal branches. Anatomic pathology focuses on the direct examination of tissues and cells — evaluating structure and abnormalities under a microscope. Clinical pathology analyzes blood, urine, and other body fluids through biochemical, microbiological, and immunological methods. In practice, these branches work in parallel. A patient with a suspected lymphoma may have blood analyzed in the clinical laboratory at the same time that a lymph node biopsy is being examined microscopically in the anatomic pathology department. In cancer and many tissue diseases, an accurate pathological diagnosis determines not just whether a patient is treated, but how, with what, and for how long.
The Laboratory at HSHS St. Mary’s Hospital Medical Center
The laboratory at HSHS St. Mary’s Hospital Medical Center delivers timely, cost-effective diagnostic pathology and laboratory services to hospital inpatients, outpatients, and patients seen through affiliated community physicians’ offices. Testing runs 24 hours per day, seven days per week, because clinical decisions rarely wait for convenient hours. Board-certified pathologists provide medical oversight, and all laboratory personnel participate in ongoing continuing education to stay current with evolving diagnostic science.
Two institutional accreditations anchor the laboratory’s quality framework. The table below identifies these bodies and what each means for patients receiving diagnostic services at St. Mary’s Hospital Medical Center.
| Accrediting Body | What It Represents | Why It Matters for Patients |
|---|---|---|
| College of American Pathologists (CAP) | The gold standard for laboratory quality assurance in the United States | Confirms peer-reviewed inspections, proficiency testing, and adherence to national performance benchmarks |
| The Joint Commission | A national healthcare accreditation and certification body | Validates that the laboratory meets or exceeds comprehensive patient safety and quality standards |
Together, these accreditations give physicians and patients well-founded confidence in the accuracy and reliability of results produced at HSHS St. Mary’s Hospital Medical Center. For tests requiring technology or expertise beyond on-site capabilities, the laboratory coordinates with reference centers including Mayo Medical Laboratories and Quest Diagnostic Laboratories.
The Department of Anatomic Pathology: Cells, Tissues, and the Architecture of Disease
Anatomic pathology examines what biological material looks like — how cells are shaped, how they are organized within tissues, and how those characteristics deviate from normal in disease. The Department of Anatomic Pathology at St. Mary’s Hospital Medical Center operates through two core sections: cytology and histology. These disciplines differ in method but share a purpose: producing an accurate microscopic picture of what is happening inside a patient’s body.
While cancer diagnosis is the most visible application, anatomic pathology is equally critical in identifying inflammatory conditions, autoimmune disorders, infectious tissue damage, and degenerative diseases that manifest at the cellular level well before they produce obvious symptoms.
Cytology: Reading the Language of Individual Cells
Cytology examines individual cells or small clusters of cells, typically gathered through minimally invasive procedures. Its key advantage is that it can yield significant diagnostic information without requiring open surgery or large tissue removal. The cytology section at HSHS St. Mary’s Hospital Medical Center processes several specimen types across a broad range of clinical applications.
The following represent the most diagnostically significant specimen categories processed through cytological analysis:
- Pap smears (cervical cytology): Cells from the cervix are examined for precancerous changes or early cervical cancer. The Pap test is among the most effective cancer screening tools in modern medicine, detecting cellular abnormalities years before a tumor becomes clinically apparent — a capability that has contributed to sustained reductions in cervical cancer mortality.
- Fine needle aspiration (FNA) specimens: A slender needle is guided into a suspicious lump — commonly in the thyroid, breast, lymph nodes, or salivary glands — to withdraw cells for microscopic examination. The FNA technique yields a meaningful diagnostic answer with minimal patient discomfort and no surgical incision.
- Body fluid specimens: Fluids from the pleural cavity, peritoneal cavity, and cerebrospinal space can be examined cytologically for infection, inflammation, or cancer that has spread beyond its primary site. Detecting malignant cells in pleural fluid, for example, is both a diagnostic finding and a factor in cancer staging.
Cytological results frequently determine the next step in a patient’s care — proceeding to surgery, obtaining additional imaging, or safely monitoring without intervention.
Histology: The Definitive Word on Tissue Structure
While cytology works with cells in relative isolation, histology examines tissue in its full structural context — preserving the spatial relationships between cell populations that reveal how a disease has organized itself and how aggressively it is behaving. The histology section at HSHS St. Mary’s Hospital Medical Center processes biopsies and surgical specimens from across the full range of organ systems, following a workflow of fixation, embedding, sectioning, and staining. In cancer, histological findings answer the questions that determine every major clinical decision that follows:
- Whether a tumor is malignant and what type of cancer cell it originates from
- The tumor’s grade — how closely cancer cells resemble their normal counterparts, indicating growth rate and aggressiveness
- Whether malignant cells have invaded surrounding blood vessels or lymphatic channels
- Whether surgical margins are clear of cancer after a tumor has been removed
- The extent of cancer involvement in lymph nodes removed at the time of surgery, a key determinant in staging and treatment planning
This constellation of findings is the foundational data oncologists and surgeons depend on when designing a treatment approach tailored to the individual patient’s disease.
How Pathology Drives Cancer Diagnosis and Treatment
Cancer services at HSHS St. Mary’s Hospital Medical Center are offered through the HSHS St. Vincent Hospital Cancer Centers, bringing together one of the largest oncology specialist teams in Northeast Wisconsin — including specialists in medical oncology, radiation oncology, gynecologic oncology, and colorectal surgery. Green Bay Oncology, the region’s leading group of medical and radiation oncologists, maintains an enhanced partnership with the hospital as part of this network.
Pathology is the starting point for every clinical conversation in that network. Before a treatment plan can be formulated, a pathological diagnosis must confirm the cancer type, characterize its biological behavior, and establish its stage.
Surgical Pathology: Turning Operative Specimens Into Treatment Roadmaps
Surgical pathology handles tissue removed during operations. When a surgeon excises a tumor from the colon, breast, lung, or another location, that specimen travels to the pathology laboratory. The resulting report covers tumor type, size, cellular grade, margin status, lymphovascular invasion, and lymph node involvement — a document that determines whether additional surgery is needed, which therapies are appropriate, and what prognosis the patient is likely to face.
Intraoperative consultation — frozen section analysis — allows a pathologist to assess a specimen while the patient remains on the operating table. A surgeon who needs to know in real time whether a margin is cancer-free, or whether a sentinel lymph node is involved, can receive a preliminary answer within minutes, reducing the likelihood of an incomplete resection or a return to the operating room.
Fine Needle Aspiration Biopsy: Precision Diagnosis Before Surgery
Fine needle aspiration biopsy cytology, available as part of the anatomic pathology service at St. Mary’s Hospital Medical Center, is one of the most patient-friendly tools in the pre-surgical workup. When imaging identifies a suspicious thyroid nodule, breast lesion, or enlarged lymph node, sampling that structure with a thin needle can prevent unnecessary operations and shorten the diagnostic timeline significantly. A benign FNA result may support active surveillance; a malignant result triggers surgical planning without delay.
Clinical Pathology: Completing the Diagnostic Picture
Clinical pathology complements anatomic testing by examining measurable markers of disease in blood, urine, and other biological fluids. The clinical laboratory at HSHS St. Mary’s Hospital Medical Center offers a comprehensive menu of diagnostic testing across multiple disciplines. The table below outlines the primary service categories and their clinical applications.
| Service Category | Primary Diagnostic Application |
|---|---|
| Hematology testing | Blood cell counts, morphology, and disorders including anemia, leukemia, and lymphoma |
| Chemistry testing | Organ function (liver, kidney, thyroid) and metabolic and hormonal markers |
| Microbiology testing | Identification of bacterial, viral, fungal, and parasitic infections |
| Immunology testing | Detection of immune dysregulation, autoimmune conditions, and infectious disease serology |
| Coagulation testing | Clotting function for bleeding disorders and anticoagulation management |
| Blood bank / Transfusion services | Blood typing, cross-matching, and compatibility testing for transfusions |
| Serology testing | Antibody and antigen detection for infectious and immune-mediated diseases |
| Outreach testing | Laboratory services extended to community-based physicians’ offices |
These are not isolated services — they operate as an integrated laboratory alongside the anatomic pathology department. Hematology testing often provides the first laboratory evidence of blood-borne malignancies, while chemistry panels reveal organ dysfunction that informs treatment tolerance assessments. Testing runs around the clock, staffed by certified medical technologists on advanced instrumentation.
Beyond Cancer: Pathology in Tissue Disease and Complex Conditions
A significant portion of anatomic pathology work involves conditions that are not malignant but require the same tissue-level precision to diagnose accurately. The pathology partnership between HSHS St. Mary’s Hospital Medical Center and Prevea Health brings board-certified pathologists with subspecialty expertise across the following clinically important domains:
- Dermatopathology: Skin biopsies are examined to diagnose inflammatory dermatologic conditions, autoimmune blistering disorders, and pigmented lesions — providing microscopic clarity that distinguishes benign atypical moles from early melanoma when clinical appearance alone is insufficient.
- Gastrointestinal pathology: Biopsies taken during colonoscopy or upper endoscopy are analyzed for Crohn’s disease, ulcerative colitis, celiac disease, Barrett’s esophagus, and colorectal neoplasia. Tissue architecture frequently distinguishes one condition from another when symptoms overlap.
- Hematopathology: Bone marrow biopsies and lymph node specimens are evaluated for Hodgkin and non-Hodgkin lymphoma, leukemia, multiple myeloma, and non-malignant blood disorders including aplastic anemia and myelodysplastic syndromes.
- Breast pathology: Biopsy and surgical specimens are assessed to differentiate benign lesions from ductal carcinoma in situ and invasive cancer, and to determine the receptor status — estrogen, progesterone, and HER2 — that determines eligibility for targeted therapies.
This subspecialty breadth means patients with diagnostically challenging conditions can receive expert anatomic evaluation without being referred outside the regional healthcare network.
What Patients Can Expect from Laboratory Services
For most patients, the pathology laboratory operates in the background. A specimen is collected, submitted, and a result appears through a physician’s office or a patient portal. The following operational features characterize how the HSHS St. Mary’s Hospital Medical Center laboratory structures its services:
- Turnaround time: A 24-hour turnaround applies to most standard laboratory tests. For urgent clinical situations, STAT testing allows physicians to act on critical results within the same encounter.
- Outpatient access: Outpatient laboratory services are available by appointment on weekdays. The laboratory requires patients to schedule an appointment and register before arriving for testing.
- Results delivery: Results are communicated through the ordering physician. Patients coordinated through Prevea Health providers can also access results via the MyPrevea patient portal.
- Reference laboratory access: When a test exceeds on-site capabilities, the laboratory coordinates referrals to Mayo Medical Laboratories and Quest Diagnostic Laboratories, keeping the process seamless for the patient.
- Preparation requirements: Some blood tests require fasting prior to the draw. The laboratory advises confirming any preparation requirements with the ordering physician before the appointment.
These operational details — accreditation, qualified personnel, STAT capability, and reference lab coordination — translate institutional quality into clinical reliability when a diagnosis is on the line.
Conclusion
Pathology and anatomic testing work behind the scenes, yet the laboratory is where the most consequential diagnostic determinations in medicine are made. The cytologist’s review of a Pap smear, the histologist’s examination of a surgical specimen’s margins, the clinical technologist’s analysis of an abnormal blood count — these are not administrative steps. They are the moments when clinical suspicion becomes a confirmed diagnosis.
HSHS St. Mary’s Hospital Medical Center has built its laboratory services around accreditation, professional expertise, and integrative capability — connecting anatomic pathology, clinical laboratory testing, cancer center partnerships, and reference laboratory access into a coherent diagnostic system. For a hospital that has served Northeast Wisconsin since 1903 as part of the Hospital Sisters Health System, the pathology department is not a peripheral support function. Whether the question involves an early cellular abnormality, a complex tumor, or a systemic disease that has yet to be fully characterized, the pathology services at St. Mary’s Hospital Medical Center are where that question begins to find its answer.