21 July 2021: Pathology Images of the Week

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

Oral cavity & oropharynx > Lingual tonsil

The posterior lateral tongue contains 6 – 8 larger red papules.

Contributed by Molly Housley Smith, D.M.D.

Ovary > Corpus luteum cyst

Intermediate magnification showing bilayered cyst lining with inner granulosa cells (lower part of the image) and outer layer of theca cells (upper part of the image).

Contributed by Aurelia Busca, M.D., Ph.D.

Stains & CD markers > WT1

The tumor cells show strong nuclear positivity for WT1. The necrotic tumor cells lose antigenicity for WT1. The final diagnosis is WT1 positive malignant mesothelioma.

Contributed by Urooba Nadeem, M.D. and Aliya N. Husain, M.D.

Bone marrow neoplastic > Chronic neutrophilic leukemia

Peripheral blood smear shows leukocytosis where almost all the cells are mature neutrophils with normal morphology. It is characteristic of chronic neutrophilic leukemia that no (or at most < 5%) immature cells at earlier stage than neutrophils and bands are noted in the peripheral blood. The neutrophils show adequate segmentation and no dyspoietic features (Wright Giemsa, 400x magnification or 40x objective).

Contributed by Roberto N. Miranda, M.D.

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30 June 2021: Pathology Images of the Week

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

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.

5 May 2021: Pathology Images of the Week

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

Bone & joints > Chondrosarcoma (primary, secondary, periosteal)

There is obvious nuclear atypia and pleomorphism but the background is distinctly chondroid.

Contributed by Shadi Qasem, M.D.

Bone marrow neoplastic > Myeloid / lymphoid neoplasms with eosinophilia and gene rearrangement > PCM1-JAK2

Bone marrow clot showing large, abnormal aggregate of early erythroid precursors. Also note dysplastic megakaryocytes (H&E stain, 200x).

Contributed by Zeba N. Singh, M.B.B.S., M.D.

Lymphoma & related disorders > Indolent T lymphoproliferative disease of the GI tract

Majority of T cells in the infiltrate are CD8 positive.

Contributed by Anamarija M. Perry, M.D.

Uterus > Leiomyoma-general > FH deficient leiomyoma

Spindle or epithelioid cells with ovoid nuclei and prominent eosinophilic nucleoli surrounded by perinucleolar halos.

Contributed by Sabrina Croce, M.D., Ph.D.


How can you search the textbook?

For desktop / tablet, you can either use the Google search bar in the upper right corner or visit PathologyOutlines.com and then scroll down to where the 59 chapters are listed, as demonstrated below.

For mobile, visit PathologyOutlines.com, click on “Chapters by Subspecialty” (as demonstrated below) and then click on the subspecialty, chapter and topic.

For any device you can use your favorite browser and type in PathologyOutlines.com in addition to the search term.

28 April 2021: Pathology Images of the Week

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

Ovary > Mucinous borderline tumor / atypical proliferative mucinous tumor

Multiloculated cyst with mucinous contents and smooth external surface.

Contributed by Russell Vang, M.D.

Placenta > Decidual arteriopathy

Advanced decidual arteriopathy with fibrinoid necrosis. Arteries are distended and show endothelial injury (detachment from the wall, arrow) and fibrinoid necrosis of the media (*). 200x original magnification.

Contributed by Jonathan L. Hecht, M.D., Ph.D.

Breast > Tubular adenoma

Eosinophilic secretions present in the lumens of some of the tubules (H&E, 20x magnification).

Contributed by Joshua J.X. Li, M.B.Ch.B. and Gary M. Tse, M.B.B.S.

Breast > Metaplastic carcinoma

Moderate to markedly cytologic atypia and frequent mitosis (200x).

Contributed by Huina Zhang, M.D., Ph.D.

Placenta > Maternal vascular malperfusion

Infarction (fresh): infarcts are typically pyramidal shape and involve the maternal floor of the placenta. Older infarcts are white, while more recent infarcts are red / heterogeneous in the fresh state.

Contributed by Jonathan L. Hecht, M.D., Ph.D.

Salivary glands > Acinic cell carcinoma

Parotid gland FNA of acinic cell carcinoma. The neoplastic cells are large with abundant finely vacuolated to granular cytoplasm (Diff-Quik).

Contributed by Arash H. Lahouti, M.D.


How can you search the textbook?

For desktop / tablet, you can either use the Google search bar in the upper right corner or visit PathologyOutlines.com and then scroll down to where the 59 chapters are listed, as demonstrated below.

For mobile, visit PathologyOutlines.com, click on “Chapters by Subspecialty” (as demonstrated below) and then click on the subspecialty, chapter and topic.

For any device you can use your favorite browser and type in PathologyOutlines.com in addition to the search term.

21 April 2021: Pathology Images of the Week

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

Kidney nontumor > Acute pyelonephritis

Acute inflammation / pus in renal calyx.

Contributed by Jian-Hua Qiao, M.D.

Liver & intrahepatic bile ducts > Combined hepatocellular carcinoma-cholangiocarcinoma

Unequivocal cholangiocytic (red arrow) and hepatocytic (blue arrow) areas of cell differentiation. The hepatocytic area shows tumor cells organized in trabeculae (H&E 100x).

Contributed by Aurélie Beaufrère, M.D.

Bone marrow neoplastic > Myeloid neoplasms with germline predisposition and other organ dysfunction with GATA2 mutation

Bone marrow core biopsy of the same patient shows megakaryocytic dysplasia (small, hypolobated) (H&E, 40x).

Contributed by Wei Wang, M.D., Ph.D.

CNS tumor > Pituicytoma

Nuclear expression of TTF1 is ubiquitous.

Contributed by Federico Roncaroli, M.D.

Muscle & peripheral nerve nontumor > Immune mediated necrotizing myopathy

Thigh muscle from a 49 year old woman with progressive proximal weakness and creatine kinase in the 7,000s. Histology shows a pauci-inflammatory IMNM. The necrotic fibers are randomly distributed and temporally heterogeneous. There is also moderate fiber size variation and frequent internalized nuclei, suggesting that myofiber damage has been going on for a while (H&E, 20x).

Contributed by Chunyu “Hunter” Cai, M.D., Ph.D.


How can you search the textbook?

For desktop / tablet, you can either use the Google search bar in the upper right corner or visit PathologyOutlines.com and then scroll down to where the 59 chapters are listed, as demonstrated below.

For mobile, visit PathologyOutlines.com, click on “Chapters by Subspecialty” (as demonstrated below) and then click on the subspecialty, chapter and topic.

For any device you can use your favorite browser and type in PathologyOutlines.com in addition to the search term.

14 April 2021: Images of the Week

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

Skin nonmelanocytic tumor > Atypical fibroxanthoma

Cytomorphologically, lesional cells are highly bizarre and atypical, with marked pleomorphism in size and shape, abundant eosinophilic cytoplasm, occasional multinucleation and numerous mitotic figures, including atypical forms (H&E, 200x).

Contributed by Pavandeep Gill, M.D. and Phyu Aung, M.D., Ph.D.

Stomach > Fundic gland polyp

Cystically dilated glands.

Contributed by Naziheh Assarzadegan, M.D.

Appendix > Enterobius vermicularis

Higher magnification shows Enterobius eggs with 1 flattened side and 1 convex side and a double layer hyaline chitin shell.

Contributed by Eiman Adel Hasby, M.D.

Bone marrow neoplastic > Atypical chronic myeloid leukemia

Bone marrow biopsy from a patient with aCML showing markedly hypercellular bone marrow with markedly increased neutrophils and myeloid precursors and mild dysmegakarypoiesis with no increase in blasts.

Contributed by Ling Zhang, M.D.

Esophagus > Undifferentiated carcinoma

Undifferentiated carcinoma at high power. Sheets of clearly high grade cells without obvious pattern of differentiation into any given cell type.

Contributed by Rondell P. Graham, M.B.B.S.


How can you search the textbook?

For desktop / tablet, you can either use the Google search bar in the upper right corner or visit PathologyOutlines.com and then scroll down to where the 59 chapters are listed, as demonstrated below.

For mobile, visit PathologyOutlines.com, click on “Chapters by Subspecialty” (as demonstrated below) and then click on the subspecialty, chapter and topic.

For any device you can use your favorite browser and type in PathologyOutlines.com in addition to the search term.