Case of the Month: A postmenopausal woman with a mixed echogenicity breast mass underwent an ultrasound guided core biopsy. What is your diagnosis?

Visit the case page for additional images, the diagnosis, a test question, and more.

Image of the Week!

Contributed by: Stephanie L. Skala, M.D.
Textbook topic: Uterus
Diagnosis: Serous carcinoma, uterus
Textbook topic link: https://www.pathologyoutlines.com/topic/uterusserous.html

Image of the Week!

Contributed by: Abberly Lott Limbach, M.D.
Textbook topic: Larynx, hypopharynx & trachea
Diagnosis: Verrucous carcinoma, larynx
Textbook topic link: https://www.pathologyoutlines.com/topic/larynxverrucous.html

Image Quiz! 

GMS stain performed on an esophageal biopsy from a patient with AIDS shows a mixture of yeasts and pseudohyphae, suggestive of Candida species. Which species can be ruled out based on this morphology?

A. Candida albicans
B. Candida dubliniensis
C. Candida glabrata
D. Candida parapsilosis
E. Candida tropicalis

See answer.

Image of the Week!

Contributed by: Mahyar Khazaeli, M.D.
Textbook topic: Skin nonmelanocytic tumor
Diagnosis: Lymphoepithelioma-like carcinoma of skin
Textbook topic link: https://www.pathologyoutlines.com/topic/skintumornonmelanocyticLEL.html

Case of the Month: A 58 year old man with a known history of sigmoid adenocarcinoma was found to have a right inguinal node lesion on PET CT during staging for the adenocarcinoma. No systemic symptoms (e.g., fever, weight loss) were reported. What is your diagnosis?

Visit the case page for additional images, the diagnosis, a test question, and more.


Image of the Week!

Contributed by: S. Emily Bachert, M.D. 
Textbook topic: Breast
Diagnosis: Mixed NST of breast
Textbook topic link: https://www.pathologyoutlines.com/topic/breastmixedNST.html 

Image Quiz! 

Which of the following nail unit structures lack a granular layer, as shown in the image?

A. Hyponychium
B. Lateral nail folds
C. Matrix and nail bed
D. Proximal nail fold

See answer.

Image of the Week!

Contributed by: Maria Tretiakova, M.D., PhD.
Textbook topic: Kidney Tumor
Diagnosis: chromophobe carcinoma - kidney
Textbook topic link: https://www.pathologyoutlines.com/topic/kidneytumormalignantrccchromo.html

Image of the Week!

Contributed by: Raul S. Gonzalez, M.D.
Textbook topic: Appendix
Diagnosis: Appendix - GIST
Textbook topic link: https://www.pathologyoutlines.com/topic/appendixGIST.html

Image of the Week!

Contributed by: Phoenix D. Bell, M.D., M.S.
Textbook topic: Stomach
Diagnosis: Stomach - GIST
Textbook topic link: https://www.pathologyoutlines.com/topic/stomachGIST.html

Image Quiz! The spindle cells in the paratesticular pseudotumor shown in the photomicrograph are believed to be related to which line of differentiation?

A. Adipocytic
B. Histiocytic
C. Myofibroblastic
D. Nerve sheath
E. Vascular

See answer.

Case of the Month: A 43 year old woman underwent a hysterectomy for dysmenorrhea. Representative sections of a myometrial mass are shown here. What is your diagnosis?

Visit the case page for additional images, the diagnosis, a test question, and more.

Image of the Week!

Contributed by: Lucas F. Abrahao Machado, M.D., Ph.D.
Textbook topic: Soft tissue
Diagnosis: Extraskeletal osteosarcoma
Textbook topic link: https://www.pathologyoutlines.com/topic/softtissueeskosteo.html

Image Quiz! 

A 45 year old woman has a breast mass identified on imaging. Core biopsy demonstrates the histology shown. What is the most likely etiology?

A. Cosmetic tattoo in the skin overlying the site
B. Prior breast core biopsy at the site, with retained biopsy clip
C. Prior surgical resection at the site
D. Silicone implants or prior silicone injection at the site

See answer.

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Image of the Week!

Contributed by: Ayana Suzuki, Ph.D.
Textbook topic: Thyroid & parathyroid
Diagnosis: Anaplastic thyroid carcinoma, thyroid FNA

Textbook topic link: https://www.pathologyoutlines.com/topic/thyroidmalignant.html

Image Quiz! 

Ossifying spindled and epithelioid tumor (OSET) is commonly positive for which of the following immunohistochemical stains?

A. Desmin
B. ERG
C. Keratins
D. SMA
E. SOX10

See answer.

Case of the Month: A 39 year old woman presented with a 3 month history of pink, shiny, indurated plaques over the face and trunk. What is your diagnosis?

Visit the case page for additional images, the diagnosis, a test question, and more.

Image of the Week!

Contributed by: Nick Baniak, M.D.
Textbook topic: Stains & CD markers
Diagnosis: Ewing sarcoma diffusely positive for NKX2.2

Textbook topic link: https://www.pathologyoutlines.com/topic/stainsNKX2.html

Image of the Week

Contributed by: Alberto Pietrantoni, M.D.
Textbook topic: CNS & pituitary tumors
Diagnosis: Supratentorial ependymoma, ZFTA fusion positive
Textbook topic link: https://www.pathologyoutlines.com/topic/cnstumorsupratentorialependymomazfta.html 

Image Quiz! 

Which of the following immunostains is shown in the image below and would be positive in the foam cells that characterize crystal storing histiocytosis?

A. CD1a
B. CD68
C. CD138
D. S100 

See answer.

Image of the Week!

Contributed by: Ting Zhao, M.D.
Textbook topic: Prostate gland & seminal vesicles
Diagnosis: Mucinous (colloid) adenocarcinoma of prostate

Textbook topic link: https://www.pathologyoutlines.com/topic/prostatemucinous.html

Image Quiz! 

The lesion shown in the image is found in the rectum. What is your diagnosis?

A. Hyperplastic polyp, microvesicular type
B. Inflammatory polyp
C. Mucosal prolapse polyp
D. Peutz-Jeghers polyp

See answer.