Cancer precursor lesions project

Characteristics of premalignant precursors, part 2 (brain and eye tumors)

In this essay, we discuss actual and possible malignant precursors associated with neuropathology.

Based on our work, it now appears that most brain and eye malignancies do NOT have a morphologic precursor. They may be initiated by a defining mutation in a single stem or progenitor cell or small cluster of cells that multiplies and acquires additional malignant properties over time. Due to its small size, detection may not be possible, at least with current methods, until it is large enough to be clinically evident.

See more on our blog here.

Glioblastoma: glomeruloid microvascular proliferation associated with EGFR amplification (contributed by Bharat Ramlal, M.D.)

Characteristics of premalignant precursors, part 3a (dermatopathology)

In the skin, of the 79 distinctive malignancies identified to date, we have identified only 6 malignancies associated with precursors (5 melanocytic, 1 nonmelanocytic).

In this essay, we discussed the precursors of the first 3 malignancies.

Invasive melanoma: precursor is dysplastic nevus
Superficial spreading melanoma (low CSD [cumulative sun damage] melanoma): precursor is also dysplastic nevus
Lentigo maligna melanoma: precursor is lentigo maligna

See more on our blog here.

Lentigo maligna. An irregularly pigmented macule on the forearm shows chronic actinic damage. Biopsy revealed melanoma in situ (lentigo maligna) (contributed by Julia Nunley, M.D.)

Characteristics of premalignant precursors, part 3b (dermatopathology)

In the skin, of the 79 distinctive malignancies identified to date, we have identified only 6 malignancies associated with precursors (5 melanocytic, 1 nonmelanocytic).

In this essay, we discuss the precursors of the last 3 malignancies.

Acral melanoma: may have acral lentiginous melanoma in situ and acral nevus as precursors
Melanoma arising in giant congenital nevus: precursor is giant congenital nevus
Squamous cell carcinoma: may have actinic keratosis / keratinocytic dysplasia and squamous cell carcinoma in situ as precursors

See the link to the full essay with images on our blog here.

Acral melanoma in situ: atypical melanocytes at the dermoepidermal junction (contributed by Carlos A. Torres-Cabala, M.D.)

Characteristics of premalignant precursors, part 4 (bone, joints and soft tissue malignancies)

This essay describes precursors associated with bone and soft tissue malignancies. In the bone, joints and soft tissue, of 140 distinct malignancies, we have identified premalignant precursors in only 4 bone malignancies (chondrosarcoma grade 1, chondrosarcoma grades 2 & 3, osteosarcoma, giant cell tumor of bone) and in no soft tissue tumors. In these 4 malignancies, premalignant precursors are rare except in syndromic or genetic disorders.

See the link to the full essay with images on our blog here.

Multiple enchondromas present in an asymmetric distribution (contributed by Mark R. Wick, M.D.)

Characteristics of premalignant precursors, part 5a (hematopathology)

In parts 5a and 5b, we discuss precursors associated with hematologic malignancies (i.e., leukemias and lymphomas arising in the bone marrow and lymphoid tissues). We have identified only 6 precursor conditions out of 207 distinct diagnoses but because the cells of the precursors and the malignancies appear similar microscopically, some of these precursors (MGUS, B cell monoclonal lymphocytosis) might be better considered as clinical precursors rather than morphologic precursors.

See the link to the full essay with images on our blog here.

IgM MGUS: Bone marrow aspirate shows slightly increased number of plasma cells (arrows), the middle arrow points to one with 2 nuclei (contributed by Ameet R. Kini, M.D., Ph.D. and Maryam F. Raouf, M.D.)

Characteristics of premalignant precursors, part 5b (hematopathology)

Hematologic malignancies only rarely have precursors. We have identified only 6 precursors associated with 207 distinct hematologic malignancies (i.e., leukemias and lymphomas arising in the bone marrow and lymphoid tissue) and these precursors typically are either not morphologic (meaning the cancer cells do not appear different microscopically between the precursor and the malignancy) or are rare.

See the link to the full essay with images on our blog here.

Follicular neoplasia in situ: High power has a somewhat monotonous appearance with no mitotic figures or tingible body macrophages, both commonly seen in reactive (benign) lymph nodes (contributed by Elaine S. Jaffe, M.D .)

Social media

Twice a week we post interesting cancer related images of malignancies

with diagnoses.

Newsletters

Click here to sign up for

this newsletter.

We list our prior newsletters on the Newsletters page as well as below.

Latest versions of our documents

Strategic plan

(updated 1 June 2023)

American Code Against Cancer

(updated 9 January 2023)