Case History

A 34-year-old male presents to the emergency department with abdominal pain. Imaging shows a circumfrential mass causing obstruction of the small bowel. Sections of the mass (H&E shown below) show a mesenteric based spindle cell proliferation with long sweeping fascicles, small blood vessels, bland cytology, no mitoses or necrosis. Immunohistochemical stain for beta catenin shows nuclear positivity in the lesional cells (IHC shown below), and they are negative for desmin, S100, CD117, and SOX10.

What is the diagnosis?

A.      Gastrointestinal stromal tumor (GIST)
B.      Leiomyoma
C.      Desmoid fibromatosis
D.      Schwannoma

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Case History

A 75-year-old female with limited past medical history presented from an outside hospital for endoscopic resection of a gastric mass.

What stain would be the most helpful in determining the diagnosis?

A.      Pancytokeratin
B.      GATA3
C.      ERG
D.      CK7

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Case History

A 45-year old female is incidentally found to have increased liver function enzymes. A liver biopsy is performed. 

What is the most likely diagnosis?

A.      Primary sclerosing cholangitis
B.      Primary biliary cholangitis
C.      Autoimmune hepatitis
D.      Acute viral hepatitis

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Case History

A 23-year-old female presents with CT identified 12 cm pelvic mass appearing to arise from right adnexa, suspicious for ovarian neoplasm. The ovary and fallopian tube were sent for pathology. Immunostaining result of BRG1 is provided.

What is the most likely diagnosis?

A.      HGSC
B.      SCCOHT
C.      GCT
D.      DLBCL


Case History

Patient with neuroimaging studies showing an 9.0 cm, in greatest dimension, destructive mass arising from dura with osseous extension. Metastatic imaging work up and Pancytokeratin IHC is negative.

What would be the top of your differential diagnosis?

A.      High grade lymphoma
B.      High grade meningioma
C.      Squamous cell carcinoma
D.      High grade glial neoplasm

 Williams Case1 2022

 Microscopic Description:

  • Microscopic sections show a malignant meningothelial neoplasm with moderately enlarged, irregularly shaped, hyperchromatic nuclei within a background of dense connective tissue. Also present is greater than 20 mitotic figures per high power field, expanded and coalescent fields of spontaneous tumor necrosis, foci of small cell change and frequent prominent nucleoli. 
  • The malignant meningothelial neoplasm is also infiltrating into marrow spaces of bone. 
  • Immunohistochemical stains performed are CD45, Pax-5, CD3, CD20, p63, GFAP and pancytokeratin were all negative within the neoplastic cells.


  • Anaplastic meningioma is a high grade meningioma with overtly malignant cytomorphology (anaplasia) that can resemble a carcinoma, high grade sarcoma or melanoma
  • It has an elevated mitotic count (greater than or equal to 20 mitotic figures per 10 high power field) which defines this as a CNS WHO grade 3 meningothelial neoplasm
  • Defined molecular alterations include harboring a TERT promoter mutation and/or having a homozygous CDKN2A and/or CDKN2B deletion.


Sahm, F., et al. Meningioma. In: WHO Classification of Tumours Editorial Board. Central nervous system tumours [Internet]. Lyon (France): International Agency for Research on Cancer; 2021 [cited 07/14/2022]. (WHO classification of tumours series, 5th ed.; vol. 6). Available from:


Case contributed by: Michael Williams, M.D., M.Sc., Neuropathology Fellow, UAB Pathology

Case History

Placenta, 27 weeks gestation.

The process pictured in the photographs is most likely due to:

A.      Ascending infection
B.      Fetal sepsis
C.      Hematogenous infection
D.      Viral TORCH infection

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Case History

The patient is a 81-year-old male with a palpable breast mass. Imaging demonstrated an oval parallel mass with indistinct margins measuring 14 x 10 x 13 mm in the right breast at 1 o'clock located 1 cm from the nipple. A lumpectomy was performed and representative sections are shown.

What is the best diagnosis?

A.      Metaplastic Carcinoma
B.      Myofibroblastoma
C.      Malignant phyllodes
D.      Cellular PASH (Pseudoangiomatous stromal hyperplasia)

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Case History

Neuro autopsy: 50 year old male, arrived to in asystole ER and pronounced dead after rounds of ACLS protocol. Toxicology screen negative, no medical or family history, and described by local shelter as “odd , rude, and never says anything”.

What immunohistochemical or special stain would be most useful in the diagnosis?

A.      Silver stain
B.      Tau
C.      Alpha synuclein
D.      Amyloid-B
E.       PrP (prion protein)
F.       IDH-1 R132H

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Case History

70-year-old female, right axillary lymph node excision

What is the diagnosis?

  1.        DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms)
  2.        AITL (Angioimmunoblastic T cell lymphoma)
  3.        Classic Hodgkin lymphoma
  4. Reactive lymph node

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