Lipomatous tumous - evolving concepts

Dr. Petur Nielsen

Lipomatous tumors span a broad age range and have a wide morphologic spectrum. However, there are certain key histological features, particularly in the context of clinical information and imaging features, that narrow the differential diagnosis. The diagnosis in many cases can be further refined or confirmed with the application of appropriate molecular studies. A historical overview of concepts in lipomatous neoplasia is useful, as some concepts have evolved and even revolved (returned) with the recent molecular investigations.

Objectives: At the end of the session delegates will be able to:

  1. Distinguish between lipoblasts and pseudolipoblasts and recognize the clinical contexts in which they occur.
  2. Determine when molecular studies such as FISH for MDM2 amplification or DDIT3 are needed to establish a diagnosis for treatment purposes.
  3. Recognize the variety of terminology and nomenclature for spindle cell lipomatous lesions as well as their clinical implications.
  4. Formulate a differential diagnosis of lipomatous lesions and their mimics based on morphology and imaging studies and apply molecular studies to arrive at the diagnosis.
  5. Recognize the wide variety of patterns seen in dedifferentatied liposarcoma and distinguish them from neoplastic mimics.

Target audience: The session will be valuable to pathology residents, pathology assistants, general and anatomic pathologists, and pathologists who specialize in the diagnosis of bone and soft tissue tumors.


Nerve Sheath Tumors

Dr. Jodi Carter

This session will cover the spectrum of benign and malignant peripheral nerve sheath tumors. Histologic and ancillary immunohistochemical testing for the diagnosis of nerve sheath tumors and the pitfalls of diagnosis on needle core biopsy will be reviewed with case illustrations. Emerging insights in the molecular pathogenesis and utility of molecular testing in subsets of nerve sheath tumors will be discussed. The session will be of interest to trainees in anatomic pathology, and practicing general, anatomic and molecular pathologists.

Objectives: At the end of the session delegates will be able to:

  1. Summarize the histologic criteria and use of ancillary immunohistochemistry
    in the diagnosis of benign nerve sheath tumors and their morphologic variants, hybrid nerve sheath tumors and non-neoplastic nerve sheath lesions.
  2. Discuss the histologic spectrum of malignant peripheral nerve sheath tumors, histologic mimics and diagnostic pitfalls on needle core biopsy.
  3. Discuss novel molecular genetic insights into nerve sheath tumor pathogenesis and their diagnostic applicability.

Immunohistochemistry of Soft Tissue Tumors: Tried & True and Some Things New

Dr. Bret Wehril

This presentation will review many immunohistochemical markers used in the diagnosis of soft tissue tumours, both old and newer ones. The expression profiles of these immunohistochemical markers will be discussed along with their potential pitfalls and limitations. The end goal is for pathologists to order panels of appropriately selected immunohistochemical markers to help confirm a soft tissue tumour diagnosis or narrow the differential diagnosis. This presentation is aimed at general and anatomical pathologists, pathology residents, and pathologists’ assistants.

Objectives: At the end of the session delegates will be able to:

  1. List antibodies, old and newer, that may be used to help distinguish one soft tissue tumour from another.
  2. Describe the expected expression patterns of these old and newer antibodies.
  3. Order and interpret an appropriate initial panel of immunohistochemical stains to help  broadly categorize neoplasms as to mesenchymal, epithelial, melanoma, or other.
  4. Order and interpret appropriate immunohistochemical stains that have greater restricted expression profiles to narrow or confirm the diagnosis of soft tissue tumours.

Fibro-Myo-Lipo-oma: A Primer on Pediatric (Myo)Fibroblastic Lesions

Dr. Kyle Kurek

This session will review some of the more common pediatric fibroblastic and myofibroblastic lesions, encompassing reactive, benign and malignant entities. The talk will highlight key histologic, immunohistochemical, and, when available, genetic features to provide a diagnostic framework for an approach to (myo)fibroblastic soft tissue lesions.

Objectives: At the end of the session delegates will be able to:

  1. Diagnose common pediatric fibrous soft tissue lesions based on key histologic features
  2. Employ ancillary studies (stains, molecular-genetic studies) to more accurately subtype soft tissue lesions
  3. Recognize the limitations of current classifications of myofibrobastic lesions

Target audience: The session will be valuable to pathology residents, pathology assistants, general and anatomic pathologists, and pathologists who specialize in the diagnosis of bone and soft tissue tumors.


Giant Cell Rich and Cystic Lesions of Bone

Dr. Petur Nielsen

Giant cell rich and cystic lesions of bone encompassed a wide variety of tumor. The typical giant cell rich tumor is the giant cell tumor of bone.  It accounts for approximately 6% of primary bone tumors and 20% of benign bone tumors.

Previously it was believed that the giant cells were probably formed by the fusion of the mononuclear neoplastic cells and it was even assumed that the giant cells might also be neoplastic.  Currently, giant cell tumor of bone is considered a neoplastic process derived from mononuclear cells exhibiting osteoblastic phenotype that express RANK-ligand (RANKL) that induces the formation of the osteoclast-type giant cells, and recently it has been shown that the neoplastic cells have mutations involving H3F3A which can be detected immunohistochemically.

Giant cell tumor of bone typically involves the end of long bones in skeletally mature individuals.  It is locally aggressive and can rarely metastasize.  A wide variety of tumor enter the differential diagnosis including chondroblastoma, non-ossifying fibroma, giant cell reparative granuloma most importantly giant cell rich osteosarcoma.  Aneurysmal bone cyst is the classic cystic lesion of bone that also contains number of osteoclast type giant cells that must be differentiated from other giant cell rich tumors and other cystic lesions of bone.  In this lecture the different giant cell rich and cystic lesions of bone will be discussed and how to distinguish them histologically and radiographically.

Objectives: At the end of the session delegates will be able to:

  1. Differentiate between a vascular anomaly, malformation, and tumor.
  2. Employ ancillary diagnostic tools to more accurately diagnose vascular anomalies.
  3. Recognize concerning features requiring clinical discussion.
  4. Discuss the need for a genetic classification of vascular anomalies

Target audience:  This lecture will be valuable to pathology residents, general and anatomic pathologists and pathologists who deal with bone tumors on a regular basis.

Additional Reading 1
Additional Reading 2


Vascular Anomalies Update

Dr. Kyle Kurek

This lecture will provide an overview of cutaneous and soft tissue vascular anomalies, focusing on malformations and benign/intermediate tumors.

Diagnostic features will be highlighted, enabling participants to more accurately describe and differentiate vascular lesions. The importance of clinical correlation for the diagnosis of vascular lesions will be stressed. The talk will also feature many recently identified genetic aberrations, stressing the need for a genetic classification of vascular anomalies to improve diagnosis and clinical outcome. This session will be of particular value to practicing general and anatomic pathologists, and of relevance to those with interest in neoplasia and molecular pathology.

Objectives: At the end of the session delegates will be able to:

  1. Differentiate between a vascular anomaly, malformation, and tumor.
  2. Employ ancillary diagnostic tools to more accurately diagnose vascular anomalies.
  3. Recognize concerning features requiring clinical discussion.
  4. Discuss the need for a genetic classification of vascular anomalies.

Notochordal Cell tumors

Dr. Petur Nielsen

It almost exclusively arises in the axial skeleton, most commonly the sacrum, followed by the skull base and the mobile spine and almost always presents as a destructive bone lesion with soft tissue extension.   Due to its similarity to the normal notochord, the assumption has been that chordomas may arise from notochordal remnants.  In adults, notochordal remnants can be found in the nucleus pulposus of the intervertebral disc and at the base of the brain, outside the bone (the so called ecchordosis physaliphora).  Chordomas, however are primary bone tumors and do not arise in the intervertebral discs or from ecchordosis but probably arise from the so-called benign notochordal cell tumor (BNCT).  Chordoma has traditionally been classified into conventional, chondroid and dedifferentiated subtypes and recently the a poorly differentiated chordoma has been recognized.

Objectives: At the end of the session delegates will be able to:

  1. Identify notochordal remnants.
  2. Diagnose benign notochordal cell tumor (BNCT) and distinguish from chordoma.
  3. Identify different subtypes of chordomas and their clinical importance.
  4. Distinguish chordoma from chondrosarcoma.

Target audience: This session with be of value to pathology residents and anatomic pathologists and pathologists who diagnose bone tumors.

Additional Reading


Cartilaginous Bone Lesions

Dr. Jodi Carter

This session will cover the spectrum of benign and malignant cartilaginous tumors of bone. Radiologic and histologic diagnostic criteria for cartilaginous tumors and the pitfalls of diagnosis on needle core biopsy will be reviewed with case illustrations. Recent updates to the WHO classification of chondrosarcoma will be reviewed. In addition, the applicability and limitations of emerging molecular genetic testing in subsets of cartilaginous tumors will be discussed. The session will be of interest to trainees in anatomic pathology, and practicing general, anatomic and molecular pathologists.
Objectives: At the end of the session delegates will be able to:

  1. Summarize the radiologic & histologic criteria and the concept of “special anatomic sites” in the diagnosis of benign and malignant cartilaginous tumors.
  2. Discuss the role for emerging molecular genetic testing in the diagnosis of cartilaginous tumors.
  3. Discuss recent changes to the WHO classification system for chondrosarcoma.

Myxoid Tumors of Soft Tissue

Dr. Bret Wehrli

This presentation will review the clinical and histomorphological features of soft tissue tumours that frequently are almost entirely myxoid in appearance or that frequently have a prominent myxoid component. Features used to distinguish one lesion from another, histological, immunohistochemical, and molecular, will be emphasized such that when faced with a myxoid soft tissue tumour, a diagnosis may be made confidently or the differential diagnosis may be narrowed to a limited number. This session will be of value to general and anatomic pathologists, pathology residents, and pathologists' assistants.
Objectives: At the end of the session delegates will be able to:

  1. Formulate an appropriate differential diagnosis when faced with a myxoid soft tissue tumour.
  2. Narrow this differential diagnosis by taking into consideration the associated clinical parameters and distinguishing histological features.
  3. Order appropriate immunohistochemical and molecular studies to help confirm or exclude diagnostic considerations.

TBD

Dr. Petur NielsenTarget audience: The session will be valuable to pathology residents, pathology assistants, general and anatomic pathologists, and pathologists who specialize in the diagnosis of bone and soft tissue tumors.


Vascular Tumors of Bone

Dr. Petur Nielsen


What Kind of Muffin?

Drs Mariam Abbas, Tawny Hung & Kimberly Wood

A term female middle eastern neonate was admitted to the Neonatal intensive Care Unit with multiple violaceous nodules that were noticed at birth. This presentation will go over the clinical and histologic work-up for such a case, as well as the common differential diagnoses to consider. Importantly, the collaboration and communication required between dermatology and pathology will be highlighted.     This presentation will be of value to residents in pathology and dermatology, general and anatomic pathologists, and dermatologists.
Objectives: At the end of the session delegates will be able to:

  1. List the three most common clinical causes for a blueberry muffin neonate and summarize the typical clinical features for each.
  2. List the three most useful clinical laboratory tests.
  3. List the three most common dermal histiocytic proliferations to consider in children.
  4. List the three most helpful immunohistochemical stains in the histologic workup of dermal histiocytic proliferations.
  5. Explain the limitations of histologic diagnosis and why collaboration with the clinician is paramount in arriving at the correct diagnosis.

"Patient referred for surgical correction of ptosis". Usual presentation of an unusual cutaneous neoplasm.

Dr. M. Nausherwan Mahmood

A very interesting dermatopathology case presentation.

The clinical presentation, histopathological features, immunohistochemical profile, management options, and prognosis of this rare entity will be discussed. The session will be of value to general pathologists, anatomic pathologists, dermatopathologists, dermatologists and ophthalmologists.

Objectives: At the end of the session delegates will be able to:

  1. Summarize main histopathological criteria for diagnosis of an unusual cutaneous neoplasm.
  2. Discuss clinical presentation, treatment options and behaviour of an unusual cutaneous neoplasm.
  3. Explain clinocopathological challenges faced in making the diagnosis and treatment of this entity.

Clinicopathological correlation on the dermatology consult service

Sabrina Nurmohamed & Dr. Karen Naert

A clinical case from the dermatology inpatient consultation service will be presented.

A 77 year old female with a clinical history of psoriasis presented with large painful red ulcerated plaques of several months duration. Histopathology and clinical photos will be used to guide the audience through this diagnostic dilemma solved by clinicopathologic correlation, with teaching and practice pearls for clinicians and pathologists.

The session will be of value to: residents training in dermatology, anatomic and general pathology; dermatologists, dermatopathologists, anatomic pathologists and lymphoma specialists.

  1. Recognize the differential diagnosis of large cell lymphoid infiltrates.
  2. Identify pitfalls in the diagnosis of MF-LCT.
  3. Develop appropriate suspicion for MF and employ effective communication in the setting of diagnostic ambiguity.

Approach to melanocytic lesions

Dr. Dirk Elston

A summary of cutaneous findings of connective tissue disease, vasculitis, melanoma and infectious entities will be presented with an emphasis on clinicopathological correlation.  The talk will be of value to pathologists, pathology residents, PAs and dermatologists.

Objectives: At the end of the session delegates will be able to:

  1. Recognize important infectious diseases of the skin.
  2. Recognize skin findings of lupus.
  3. Recognize skin findings of dermatomyositis.

Cutaneous infection/infestations

Dr. Dirk Elston

Objectives: At the end of the session delegates will be able to:

  1. Recognize fungal pathogens
  2. Recognize parasites

AJCC 8th edition for melanoma

Dr. M. Nausherwan Mahmood

An update on all the new changes proposed for the staging of cutaneous melanoma in the 8th edition of AJCC staging manual. All changes to different pathological parameters will be discussed. The session will be of value to general pathologists, anatomic pathologists, dermatopathologists, dermatologists, oncologists and surgeons.

Objectives: At the end of the session delegates will be able to:

  1. List new changes to the AJCC pTNM staging of cutaneous melanoma.
  2. Compare the differences between the 7th and 8th editions of AJCC staging criteria for cutaneous melanoma.
  3. Discuss important histopathological parameters for staging of cutaneous melanoma.

Challenging Cases in Childhood Melanoma

Dr. Charlene Hunter

This session provides an approach to diagnosis of challenging melanocytic proliferations in young patients using cases from our day to day practice.  This presentation will be of value to residents in pathology and dermatology, general and anatomic pathologists, and dermatologists.

Objectives: At the end of the session delegates will be able to:

  1. Identify the challenges for pathologists in the diagnosis of melanoma in a young patient.
  2. List some of the morphologic and molecular features of melanoma variants (esp. spitzoid melanoma.
  3. Discuss management strategies for melanoma in a young patient.

Rheumatologic diseases

Dr. Dirk Elston

Objectives: At the end of the session delegates will be able to:

  1. Diagnose connective tissue diseases accurately
  2. Diagnose vasculitis accurately

Review of common dermpath diagnoses for the surgical pathologist

Dr. Tawny Hung

This presentation will discuss ten diagnoses that are frequently encountered in dermatopathology.

The key histologic features for each diagnosis will be emphasized, and common pit-falls will be highlighted. This session will be of value to pathology and dermatologist residents, dermatologists, and anatomical pathologists.
Objectives: At the end of the session delegates will be able to:

  1. Identify key histologic features in some common dermpath diagnoses.
  2. Differentiate these diagnoses from others with similar histologic features.
  3. Delect appropriate immunohistochemical ains (where necessary) in the work-up of these diagnoses.

Clinicopathological correlation for non-specific dermatoses

Dr. Dirk Elston

Objectives: At the end of the session delegates will be able to:

  1. Recognize clinical correlates of stratum corneum changes.
  2. Recognize clinical correlates of epidermal changes.

 All in the Family

Dr. Pavandeep Gill

A rare and interesting case was referred to the Dermatopathology Group at Calgary Laboratory Services. A young female with a strong family history of cancer presented with multiple atypical Spitz tumours. We will identify the common genomic aberrations found in Spitzoid neoplasms, discuss the possibility of hereditary syndromes in patients with similar presentations, and offer recommendations to aid in the diagnosis and management of these patients. This session will be of interest to dermatopathologists, dermatologists, molecular pathologists, molecular geneticists, and anatomical and general pathologists.

Objectives: At the end of the session delegates will be able to:

  1. Identify the common genomic aberrations found in Spitzoid neoplasms
  2. Develop appropriate suspicion for hereditary tumour syndromes in patients presenting with multiple atypical Spitz tumours and a strong family history of cancer
  3. Discuss management recommendations for patients with a Spitz tumour-associated hereditary syndrome