Here is a selection of new images from our free, online textbook:

Bone marrow neoplastic > Transient abnormal myelopoiesis associated with Down syndrome
Bone marrow aspirate: blasts with cytoplasmic blebs.
Contributed by Tayler A. van den Akker, M.D.

Muscle & peripheral nerve nontumor > Antisynthetase syndrome associated myositis
57 year old man with positive Jo1 antibody and interstitial lung disease. H&E shows necrotic fibers and myophagocytosis predominantly involving perifascicular fibers. The perimyisial connective tissue appears edematous and fragmented.
Contributed by Chunyu “Hunter” Cai, M.D., Ph.D.

Ovary > Clear cell carcinoma
Clear cell carcinoma with a predominant tubulocystic growth pattern.
Contributed by Gulisa Turashvili, M.D., Ph.D.

Prostate gland & seminal vesicles > Sarcomatoid carcinoma
A monophasic sarcomatoid carcinoma shows only a spindle cell component with mesenchymal appearance, without admixed carcinoma. Extensive sampling and history of prostatic adenocarcinoma, preferably with immunohistochemical (keratins, rarely PSA or other prostatic markers) evidence of epithelial differentiation, helps establish the diagnosis.
Contributed by Steven Christopher Smith, M.D., Ph.D.

Stains & molecular markers > PRAME
Positive nuclear staining for PRAME in seminiferous tubules.
Contributed by Cecilia Lezcano, M.D.