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William Diehl, MD, FACS
out of 5
  • Breast Surgery
  • Breast Care Center
  • Cancer Services
  • Surgical Oncology
Accepting new patients

Appointments: Call 973-404-9945


Location Pin Icon

150 Park Avenue Breast Surgery

150 Park Avenue
2nd Floor
Florham Park, NJ 07932
United States

Clinical Expertise

  • Abnormal mammogram support
  • Abscess excision
  • Acute myelogenous leukemia (AML)
  • Additional / adjuvant therapy
  • Anaplastic large cell lymphoma (ALCL)
  • Anaplastic large-cell lymphoma
  • Anemia
  • Anticardiolipin antibodies
  • Antiphospholipid antibodies
  • Antithrombin III deficiency
  • Aplastic anemia
  • Aromatase Inhibitors
  • B12 deficiency
  • Bile duct cancers
  • Bladder cancer
  • Blood diseases
  • Blood transfusions
  • Bone marrow aspiration
  • Bone marrow biopsy
  • Breast biopsy education
  • Breast biopsy support
  • Breast cancer
  • Breast cancer coordinated care services
  • Breast cancer counseling resource support
  • Breast cancer education
  • Breast cancer health care support
  • Breast cancer lifestyle modification
  • Breast cancer nurse navigation
  • Breast cancer risk assessment support
  • Breast cancer support
  • Breast cancer support groups
  • Breast cancer surgery support
  • Breast cancer survivor plan of care
  • Breast cancer survivor support
  • Breast disease education and support
  • Breast disease nurse navigation
  • Breast health education and support
  • Breast health nurse navigation
  • Breast imaging
  • Breast treatment with nurse navigation
  • Breast ultrasound education and support
  • CMML
  • Cancer care
  • Cancer survivor support
  • Chemoprevention
  • Chemotherapy
  • Chemotherapy clinical trials
  • Chemotherapy side effect support
  • Chronic lymphocytic leukemia (CLL)
  • Chronic myelogenous leukemia (CML)
  • Clinical trials
  • Colon cancer
  • Complete blood count
  • Cooley's anemia
  • Counseling resource support
  • Cutaneous ALCL
  • Cyst excision
  • Deep vein thrombosis (DVT)
  • Diffuse large B-cell lymphoma
  • Ductal carcinoma in situ / DCIS nurse navigation
  • Duodenal cancer
  • Endocrine tumors
  • Esophageal cancer
  • Esophageal tumors
  • Excisional breast biopsy support
  • Extreme fatigue
  • Factor 5 Leiden
  • Follicular lymphoma
  • Frequent bruising
  • Frequent fever
  • Frequent nosebleed
  • Gallbladder
  • Gallbladder cancer / carcinoma
  • Gastric cancer
  • Gastrointestinal tumors
  • Head and neck cancer
  • Hemochromatosis
  • Hemoglobin H disease
  • Hemophilia
  • Hepatic tumors
  • Hepatocellular carcinoma
  • Hodgkin lymphoma
  • Hormone therapy
  • I&D (incision and drainage) abscess
  • Image - guided biopsy support
  • Immunotherapy
  • Inflammatory breast disease nurse navigation
  • Invasive ductal cancer nurse navigation
  • Invasive lobular cancer nurse navigation
  • Iron level test
  • Laparoscopic Surgery
  • Laryngeal cancer
  • Leukemia
  • Leukocytopenia
  • Leukocytosis
  • Lipoma excision
  • Liver Resection
  • Liver cancer
  • Liver tumors
  • Lobular carcinoma in situ nurse navigation
  • Lumbar puncture
  • Lump in groin
  • Lump in neck
  • Lump under arm
  • Lupus anticoagulant
  • Lymph Node Biopsy/excision
  • Lymphocytic leukemia
  • Lymphoma
  • Mammogram education and support
  • Mantle cell lymphoma
  • Marginal zone lymphoma
  • Mastectomy education and support
  • Metastatic breast cancer nurse navigation
  • Minimally invasive technique
  • Multidisciplinary breast treatment
  • Multiple myeloma
  • Myelodysplastic syndrome (MDS)
  • Myelogenous leukemia
  • Myeloproliferative disorders
  • Nasopharyngeal cancer
  • Neoadjuvant chemotherapy
  • Non-Hodgkin lymphoma
  • Non-small cell lung cancer
  • Open Surgical procedures
  • Oropharyngeal cancer
  • Ovarian cancer
  • PET
  • Pain Management
  • Pain on left side of belly
  • Pancreatic
  • Pancreatic cancer
  • Pathology review
  • Peritoneal cancer
  • Platelet disorders
  • Polycythemia vera (PV)
  • Porta Cath (Central IV access)
  • Positron emission tomography (PET)
  • Prostate cancer
  • Protein C deficiency
  • Prothrombin gene mutation
  • Pulmonary embolism (PE)
  • Radiation therapy
  • Raised red bumps on skin
  • Rectal Cancer
  • Rectal cancer
  • Red blood cell disorders
  • Renal cell cancer
  • Retroperitoneal Tumor
  • Risk-reduction medications
  • Robotic surgery
  • Sarcoma
  • Sentinal node biopsies
  • Sentinel node mapping
  • Sickle cell anemia
  • Skin cancer
  • Small Bowel
  • Small cell lung cancer
  • Soft tissue tumors
  • Spleen
  • Splenectomy
  • Stem cell transplant
  • Stomach cancer
  • Surgical robot
  • Swollen glands
  • Swollen lymph nodes
  • Systemic ALCL
  • Tamoxifen
  • Thalassemia
  • Thrombocytopenia
  • Thrombocytosis
  • Thrombophilia
  • Tonsillar cancer
  • Whipple Procedure
  • White blood cell disorders

Accepted Insurances

Always check with your health insurance carrier before scheduling any type of service. You can learn the details of your individual health insurance plan, including the amount of your copay, deductible, and coinsurance by visiting your health insurance company's website or by calling their customer service department. Click here to review our list of accepted insurance plans.

Training and Education

Board Certification

  • General Surgery, American Board of Surgery

Medical School

  • Autonomous University of the State of México, México


  • General Surgery, Indiana University Medical Center, Indianapolis, IA


  • General Surgery, Morristown Medical Center, Morristown, NJ


  • General Surgical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY

About Me

William L. Diehl specializes in the evaluation, diagnosis and treatment of breast cancer and other diseases of the breast. Dr. Diehl is a breast surgeon and surgical oncologist with extensive experience in the field of breast cancer and breast diseases. He trained at the prestigious Memorial Sloan-Kettering Cancer Center and personally treats over 200 new breast cancer patients a year.

Dr. Diehl was among the first surgeons to perform sentinel node mapping, a technique to identify the spread and stage of breast cancer, helping to determine the best therapy while limiting the amount of surgical trauma to the patient. He is an expert in minimally invasive breast biopsy techniques such as Stereotactic and Ultrasound guided biopsies. He is a strong proponent of breast preserving surgery and other cosmetically enhancing procedures for the treatment of breast cancer such as nipple sparing mastectomies, immediate reconstruction and oncoplastic procedures to provide an optimal surgical treatment while simultaneously utilizing the skills of his plastic surgery colleagues to optimize symmetry and cosmetic improvements.

Dr. Diehl is a member of the American College of Surgeons, the American Society of Breast Surgeons, the American Medical Association, the Medical Society of New Jersey and the Morris County Medical Society. He currently serves as director of the Breast Care Center at Summit Health where he oversees the delivery of breast Health Services for patients. Previously, Dr. Diehl was a member of the New Jersey department of Health/Medical Society of New Jersey Breast Imaging Options Work Group that advised the Governor and the Commissioner of Health on breast imaging and treatment to help establish legislative policy. He has also served as the Medical Director of Saint Clare's Hospital Women's Breast Health Care Center and as the director of the Morristown Medical Center multi-disciplinary Breast Cancer Panel. Dr. Diehl is a past president of the Morris County Medical Society and American Cancer Society Morris unit.

With a passion for teaching, Dr. Diehl is active in the training of young surgeons at Morristown Medical Center, and a recipient of the John Alkhas Teaching Award. He also received the Sharing Village 2007 annual Humanitarian Award and is a co-founder of the nonprofit organization UHMLA, which provides Surgical Services to underserved patients in Latin America. Twice a year he assembles a group of surgeons, nurses and anesthesiologists to travel to Central and South America to perform surgery on patients who would otherwise not have access to health care.

Dr. Diehl is featured in New Jersey Monthly’s ‘Top Doctors’, Inside Jersey’s ‘Top Cancer Doctors’, and Castle Connolly’s ‘Best Doctors in America’, ‘Top Doctors in the New York Metro area’, and ‘America’s Top Doctors’ listings, which have been reported in U.S. News and World Report. Additionally, he has been featured in Inside Jersey’s ‘Top Doctors for Women's Health’ listing for his expertise in breast cancer surgery.

English, Spanish

Hospital Affiliations

  • Morristown Medical Center

Awards and Honors

  • Top Doctors 2020
  • Top Doctors 2019
  • Top Doctors 2018
  • Top Doctors 2017
  • Top Doctors 2016
  • Top Doctors 2015
  • Top Doctors 2014
  • Patients' Choice
  • Castle Connolly Top Doctors

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