CD-117 Immunohistochemistry at Lahore PCR Lab

CD-117 Immunohistochemistry at Lahore PCR Lab

Immunohistochemistry (IHC) represents a cornerstone of modern diagnostic pathology, bridging the gap between cellular morphology and molecular profiling. Among the diverse array of biomarkers utilized in oncopathology, CD-117 (also known as c-KIT) stands out as a critical diagnostic and therapeutic marker. CD-117 Immunohistochemistry at Lahore PCR Lab is a specialized laboratory evaluation performed on tissue biopsy specimens to detect the expression of the CD-117 protein. This protein is a 145 kDa transmembrane receptor tyrosine kinase encoded by the KIT proto-oncogene, which plays a vital role in intracellular signaling cascades regulating cell survival, proliferation, chemotaxis, and adhesion.

In normal physiological states, CD-117 is expressed in hematopoietic stem cells, mast cells, melanocytes, and the interstitial cells of Cajal (the pacemaker cells of the gastrointestinal tract). However, aberrant expression or mutational activation of CD-117 is strongly associated with specific neoplastic conditions, most notably gastrointestinal stromal tumors (GISTs) and mast cell proliferative disorders. By utilizing highly specific monoclonal antibodies, the pathological team at Lahore PCR Lab can visualize the presence, distribution, and intensity of CD-117 expression within a tissue sample under a light microscope.

This diagnostic precision is paramount for establishing an accurate diagnosis, differentiating histologically similar tumors, predicting clinical behavior, and determining eligibility for targeted tyrosine kinase inhibitor (TKI) therapies such as imatinib mesylate. Consequently, CD-117 IHC is not merely a diagnostic test but a critical guide for personalized oncological management, helping clinicians in Lahore and across Pakistan deliver targeted, evidence-based care.

Clinical Procedure: What to Expect

Patient Preparation

Because CD-117 Immunohistochemistry is performed on tissue samples that have already been obtained via biopsy or surgical resection, the patient does not need to undergo any direct preparation for the laboratory test itself. However, the following guidelines are essential for ensuring a seamless testing process at Lahore PCR Lab:

• Submission of Tissue Blocks and Slides: Patients or referring clinics must provide the formalin-fixed, paraffin-embedded (FFPE) tissue block along with the corresponding hematoxylin and eosin (H&E) stained slides.
• Clinical History and Previous Reports: It is highly recommended to submit all relevant clinical histories, previous pathology reports, and imaging findings (such as CT or MRI scans) to assist the consultant pathologist in clinical correlation.
• Specimen Integrity: Ensure that the tissue specimen was properly fixed in 10% neutral buffered formalin within the recommended cold ischemia time to prevent antigen degradation.
• No Fasting Required: Since no direct blood draw or physical examination of the patient is required for this laboratory phase, fasting or medication adjustments are unnecessary unless specified for the primary biopsy procedure.

During the Procedure

The laboratory workflow for CD-117 Immunohistochemistry at Lahore PCR Lab involves a series of highly controlled, quality-assured steps executed by skilled histotechnologists and evaluated by consultant pathologists:

• Tissue Sectioning: The submitted paraffin block is mounted on a microtome, and ultra-thin sections (typically 3 to 4 microns thick) are cut and mounted on positively charged glass slides to ensure optimal tissue adhesion.
• Deparaffinization and Rehydration: The slides are heated and treated with xylene and descending grades of alcohol to remove the paraffin wax and rehydrate the tissue sections.
• Antigen Retrieval: Formalin fixation causes cross-linking of proteins, which can mask the CD-117 antigen. The laboratory utilizes advanced heat-induced epitope retrieval (HIER) techniques using specialized buffer solutions to unmask the target proteins.
• Primary Antibody Incubation: The tissue sections are incubated with a highly specific anti-CD117 monoclonal antibody. If CD-117 is present in the tissue, the antibody binds specifically to the receptor tyrosine kinase.
• Detection System and Chromogen Visualization: A secondary antibody conjugated with an enzyme (such as horseradish peroxidase) is applied, followed by a chromogen substrate (usually diaminobenzidine or DAB). This chemical reaction produces a visible brown precipitate at the site of antigen-antibody binding.
• Counterstaining and Mounting: The slides are counterstained with hematoxylin to visualize cellular nuclei, dehydrated, and coverslipped for microscopic examination.
• Microscopic Analysis: A consultant pathologist examines the slides under a high-resolution light microscope, evaluating the staining pattern (membranous, cytoplasmic, or paranuclear dot-like) and intensity.

When is a CD-117 Immunohistochemistry Performed?

Suspected Gastrointestinal Stromal Tumors (GIST)

Gastrointestinal stromal tumors are the most common mesenchymal neoplasms of the digestive tract, originating from the interstitial cells of Cajal. Because GISTs can histologically mimic other mesenchymal tumors like leiomyomas, leiomyosarcomas, schwannomas, and solitary fibrous tumors, definitive diagnosis is impossible based on standard H&E staining alone. Physicians request CD-117 IHC because approximately 95% of GISTs exhibit strong and diffuse cytoplasmic or membranous positivity for CD-117. Identifying CD-117 expression confirms the diagnosis of GIST and qualifies the patient for targeted therapy with tyrosine kinase inhibitors.

Evaluation of Mast Cell Disorders and Mastocytosis

Mastocytosis is characterized by the abnormal clonal proliferation and accumulation of mast cells in various organs, including the skin, bone marrow, spleen, and liver. Normal and neoplastic mast cells strongly express CD-117. Pathologists utilize CD-117 IHC on bone marrow biopsies or skin lesions to clearly highlight, count, and evaluate the morphological features of mast cell aggregates. This is essential for diagnosing systemic mastocytosis, cutaneous mastocytosis, and mast cell leukemia, as well as distinguishing them from reactive mast cell hyperplasia.

Classification of Acute Myeloid Leukemia (AML)

In hematopathology, CD-117 is an important marker for identifying myeloid lineage cells. During the evaluation of bone marrow aspirates and trephine biopsies for suspected leukemia, CD-117 IHC helps identify myeloblasts. It is particularly useful in distinguishing acute myeloid leukemia (AML), where blasts are frequently CD-117 positive, from acute lymphoblastic leukemia (ALL), which is typically negative. This distinction is critical for selecting the correct chemotherapy protocol.

Diagnosis of Germ Cell Tumors (Seminoma)

CD-117 is highly expressed in certain germ cell tumors, particularly testicular seminomas and ovarian dysgerminomas. When a patient presents with a testicular or pelvic mass, pathologists perform CD-117 IHC to differentiate seminomas from embryonal carcinomas, yolk sac tumors, and choriocarcinomas, which are generally negative or show different staining patterns. Accurate classification dictates whether the patient undergoes specific surgical, radiotherapeutic, or chemotherapeutic interventions.

Differentiation of Mesenchymal and Spindle Cell Neoplasms

Spindle cell lesions in the abdomen, retroperitoneum, or soft tissues present a significant diagnostic challenge due to overlapping cytological features. CD-117 IHC is routinely included in a comprehensive antibody panel to differentiate GISTs from other spindle cell neoplasms such as intra-abdominal fibromatosis (desmoid tumors), schwannomas, and smooth muscle tumors. A negative CD-117 result, combined with other markers like S100, SMA, or Desmin, helps rule out GIST and establish alternative diagnoses.

What Does a CD-117 Immunohistochemistry Detect?

CD-117 Immunohistochemistry provides detailed cellular and molecular insights. The test detects and evaluates several key pathological parameters:

• Presence or absence of the c-KIT receptor tyrosine kinase protein in tissue samples.
• Diffuse cytoplasmic staining patterns characteristic of classic gastrointestinal stromal tumors.
• Membranous staining patterns indicating localized receptor expression on the cell surface.
• Paranuclear dot-like (Golgi-zone) staining, frequently observed in specific GIST subtypes.
• Abnormal accumulation and clustering of mast cells in bone marrow trephine biopsies.
• Expression of CD-117 in myeloblasts, aiding in the subtyping of myeloid neoplasms.
• Strong, diffuse membranous positivity in testicular seminoma cells.
• Strong, diffuse membranous positivity in ovarian dysgerminoma cells.
• Negative expression in leiomyomas, helping rule out benign smooth muscle tumors.
• Negative expression in schwannomas, ruling out peripheral nerve sheath tumors.
• Negative expression in desmoid-type fibromatosis, preventing misdiagnosis of aggressive retroperitoneal masses.
• The proportion of tumor cells expressing CD-117 (percentage of positivity).
• The intensity of staining, graded as weak, moderate, or strong.
• Co-expression patterns when analyzed alongside other markers like DOG1, CD34, S100, and Desmin.
• Presence of CD-117 positive interstitial cells of Cajal in normal gastrointestinal tissue margins.
• Atypical mast cell morphology (spindle-shaped mast cells) in systemic mastocytosis.
• Residual disease or metastatic deposits of GIST in lymph nodes or peritoneal fluid.
• Treatment-induced changes or loss of CD-117 expression in post-therapy tumor resections.
• Clear demarcation of tumor boundaries in complex surgical resection specimens.
• Specific cellular localization of the antigen to confirm technical validity of the staining run.

Turnaround Time and Report Access at Lahore PCR Lab

At Lahore PCR Lab, we understand that timely and accurate pathology reports are vital for initiating prompt clinical decisions and oncological treatments. The turnaround time for CD-117 Immunohistochemistry typically ranges from 3 to 5 working days. This timeframe ensures that the tissue undergoes meticulous processing, optimal antigen retrieval, precise staining, and thorough microscopic evaluation by our consultant pathologists. To enhance patient convenience, Lahore PCR Lab provides multiple ways to access diagnostic reports. Patients and referring physicians can securely download reports directly from the official Lahore PCR Lab online portal. Additionally, automated SMS notifications are sent to patients as soon as the verified report is ready, allowing for immediate access and seamless integration into clinical care pathways.

CD-117 Immunohistochemistry Findings Overview

Structure / Parameter Evaluated	Normal Findings	Possible Abnormal Findings
Gastrointestinal Mesenchymal Tissue	Negative in smooth muscle cells; positive only in normal interstitial cells of Cajal (pacemaker cells).	Strong, diffuse cytoplasmic or membranous CD-117 positivity in spindle or epithelioid cells, indicating GIST.
Bone Marrow Trephine Biopsy	Scattered, isolated normal mast cells and early myeloid progenitors show CD-117 positivity.	Dense aggregates of atypical, spindle-shaped mast cells (systemic mastocytosis) or increased CD-117 positive myeloblasts (AML).
Testicular Tissue	Positive expression limited to normal spermatogonia within seminiferous tubules.	Diffuse, strong membranous CD-117 positivity in sheets of neoplastic germ cells, confirming Seminoma.
Ovarian Tissue	Negative in normal ovarian stroma and epithelial elements.	Diffuse CD-117 positivity in neoplastic cells, indicating Dysgerminoma.
Skin Biopsy	Scattered normal dermal mast cells and melanocytes show physiological CD-117 expression.	Dense dermal infiltrates of CD-117 positive mast cells, diagnostic of Cutaneous Mastocytosis (Urticaria Pigmentosa).
Mesenchymal Tumors (Non-GIST)	Typically negative (e.g., leiomyomas, schwannomas, desmoid tumors are CD-117 negative).	Aberrant weak or focal positivity in rare non-GIST tumors, requiring correlation with DOG1 and CD34.
Staining Intensity & Pattern	Physiological, localized, and expected intensity in normal control tissues.	Strong, diffuse (3+) membranous, cytoplasmic, or paranuclear dot-like staining in neoplastic cells.

Note: Diagnostic findings should always be interpreted by a qualified healthcare professional together with the patient’s symptoms, medical history, physical examination, laboratory investigations, previous imaging studies, and other relevant clinical information. Additional investigations or specialist consultation may be recommended depending on the findings.

Why Choose Lahore PCR Lab for CD-117 Immunohistochemistry?

• Experienced Healthcare Professionals: Our pathology department is led by highly qualified consultant pathologists with extensive expertise in oncopathology and molecular diagnostics.
• Patient-Focused Care: We prioritize patient comfort, clear communication, and compassionate support throughout the diagnostic journey.
• Quality Diagnostic Services: Lahore PCR Lab adheres to strict internal and external quality control protocols to ensure maximum diagnostic accuracy.
• Professional Reporting: Reports are structured, comprehensive, and include detailed microscopic descriptions, staining intensity, and clinical correlations.
• Modern Diagnostic Approach: We utilize advanced antigen retrieval systems and high-affinity monoclonal antibodies for superior staining quality.
• Comfortable Environment: Our sample collection centers and facilities in Lahore are designed to provide a clean, safe, and comfortable experience.
• Convenient Location: Located centrally in Lahore, our laboratory is easily accessible for patients and sample drop-offs from across the city.
• Commitment to Accurate Diagnosis: We are dedicated to providing precise, evidence-based diagnostic insights that form the foundation of effective cancer treatment plans.