Cancer Services

Diagnosing Disease

Pathology

The departments of pathology that serve our programs are divided into anatomic, or tissue pathology, and clinical pathology, or laboratory medicine. Subspecialties represented by the pathologists are blood banking, hematopathology, dermatopathology, and cytopathology.

Anatomic Pathology

Our pathology services include a comprehensive range of diagnostic tests to establish a diagnosis of cancer. The histopathology laboratory forms the foundation of this diagnostic role, because accurate diagnoses of more than 90 percent of cancers are based on routine histopathologic testing.

For those tumors that require classification through histopathologic testing, more extensive testing is available through the pathology department, including electron microscopy, flow cytometry, DNA analysis, and immunohistochemistry.
   

Clinical Pathology

The pathology laboratories interpret several cancer screening tests, including the PSA (prostate specific antigen, a prostate cancer screening test), Beta HCG (human chorionic gonadotropin, for choriocarcinoma) and the CEA test. CEA, or carcino embryonic antigen testing, is useful in follow-up of certain malignancies, especially gastrointestinal cancers.

Of course, pathology department's Fine Needle Aspirate (FNA) suite offers an alternative method of diagnosis. Physicians may refer patients to a cytopathologist who performs the actual procedure and prepares and interprets the slides to establish a diagnosis. Thyroid and breast cancers are the most frequently referred cases, followed by lymph node masses and unspecified palpable masses.

The ThinPrep Pap test has overcome many of the limitations of the conventional Pap smear. Rather than smearing the cervical sample onto a slide as is done with the Pap smear, the collection device is rinsed in a vial of preserving solution. The specimen is then sent to a laboratory, where an instrument is used to disperse and filter the contents onto a slide for microscopic examination This process is also helpful in the microscopic examination of body fluids and cytologic samples from other sites.

Radiology

Memorial Hermann's departments of radiology play critical roles in the diagnosis and staging of cancer. The radiologists associated with our programs employ a full range of sophisticated, computerized imaging studies and sonographic modalities, as well as standard radiographic and interventional procedures.

While standard X-ray remains important to the diagnosis of tumors of the chest and bone, computed tomography (CT) provides an enhanced image. CT is particularly useful in determining the stage of a neoplasm in the abdomen, pelvis, and mediastinum by clearly demonstrating its size and anatomical relationships.

The fine resolution offered by magnetic resonance imaging (MRI) augments the evaluation of tumors of the brain, spinal cord, and soft tissues, either primary or metastatic to other organs. Radioisotopic bone scanning is essential to the early detection of metastatic disease to the bone.

Advances in high-resolution diagnostic ultrasound have made this modality accurate and reliable in the diagnosis of many tumors of the abdomen, including liver, pancreas, kidney, and gallbladder. In addition, because of its portability, ultrasound can be used in intensive care units and operating rooms to localize small tumors. Our radiology departments perform a large number of percutaneous needle biopsies annually. The use of automated core needles have increased diagnostic accuracy to more than 90 percent for these types of percutaneous needle biopsies. A variety of modalities, such as CT, fluoroscopy, and ultrasound are used to guide the needle safely to the target organ.

Stereotactic needle biopsy is also used in our programs to diagnose non-palpable and calcified lesions of the breast as an alternative to open surgery after needle localization.

Also of value in the diagnosis and treatment of neoplasms are interventional radiology and special procedures. Radiologists perform arteriograms to examine the vascular blood supply to neoplasms, to introduce catheters selectively into the feeding vessel, and to deliver concentrated chemotherapy treatment. This technique can also be used to occlude circulation to the vessels as part of the modality of treatment.

Fluoroscopic procedures remain highly accurate and are easily performed on an outpatient basis to diagnose cancers of the gastrointestinal tract, including the colon, stomach, and esophagus. In fluoroscopy, the hollow organs are filled with barium sulfate solution to study their architecture and motion, facilitating the detection of intraluminal tumors, or strictures.