30 November 2011 - Case #225
All cases are archived on our website. To view them sorted by case number, diagnosis or category, visit our main Case of the Month page. To subscribe or unsubscribe to Case of the Month or our other email lists, click here.
This case was contributed by Jerad M. Gardner, M.D. and Ruan T. Ramjit, M.D., Emory University, Georgia (USA).
CancerTYPE ID is a standardized, objective molecular test based on the differential expression of 92 genes, that classifies tumors by matching the gene expression pattern of a patients tumor tissue to a database of known tumor types and histological subtypes.
CancerTYPE IDs database includes 2,206 tumors from multiple tumor banks, selected to provide broader and deeper representation of the heterogeneity of tumors. The 92-gene assay does not overlap with IHC markers, providing complementary data to standard tumor diagnosis.
CancerTYPE ID uses real-time reverse transcription polymerase chain reaction (RT-PCR). A very low copy number of RNA molecules can be detected, thus reducing the sample tissue required for testing. Testing is conducted and results are generated at bioTheranostics' CAP-accredited, CLIA-certified laboratory.
For more information, click here.
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Case #225
Clinical history:
A 73 year old man had a 4 month history of progressive right leg swelling with tender nodules, which began with a splinter injury while chopping firewood. Past medical history is remarkable for treated non-Hodgkins lymphoma, diagnosed 2 years previously. The nodules were biopsied.
Clinical image:
Microscopic images:
What is your diagnosis?
Diagnosis: Prototheca wickerhamii
Discussion:
The organism was cultured on blood, chocolate and Sabourauds dextrose agar. After 2 days, the organism appeared as yeast-like colonies on all media.
Microscopic examination of the culture plates showed multiple spherical organisms in clusters with thick walls. The organism cultured on the agar plates was inoculated onto an API 20 C AUX strip (bioMerieux Inc., Durham, NC, USA), used to identify the most frequently encountered yeasts. Based on the results of the carbohydrate assimilation tests on this panel, the organism was identified as Prototheca wickerhamii.
Prototheca was first recognized as a human pathogen in 1964 (J Clin Microbiol 2004;42:4907). 2 species are associated with human disease P. wickerhamii and P. zopfii. These fungi-like organisms are actually aerobic, achlorophyllous, algae-like, unicellular organisms commonly present in water, sewage and soil. Human infection is rare, and usually occurs via trauma or contaminated water and involves the face or exposed extremities. Patients are often immunocompromised (Arch Pathol Lab Med 2011;135:941, Am J Surg Pathol 1994;18:1261). Patients present with erythematous plaques, nodules or superficial ulcers.
Histologically, there are necrotizing granulomas containing spherical organisms with central basophilia, internal septation and double layered cell walls. There may also be multiple endospores 2 - 4 microns in size. Green algae may appear similar but contain abundant cytoplasmic starch granules (Arch Pathol Lab Med 1978;102:353).
Recommended treatment is surgery or Amphotericin B for disseminated disease. In this case, the patient had rapid progression of his disease in a lymphangiitic pattern. He was admitted to the hospital with a plan to either debride or amputate the leg but died before surgery began. No autopsy was performed.
All cases are archived on our website. To view them sorted by case number, diagnosis or category, visit our main Case of the Month page. To subscribe or unsubscribe to Case of the Month or our other email lists, click here.
This case was contributed by Jerad M. Gardner, M.D. and Ruan T. Ramjit, M.D., Emory University, Georgia (USA).
CancerTYPE ID is a standardized, objective molecular test based on the differential expression of 92 genes, that classifies tumors by matching the gene expression pattern of a patients tumor tissue to a database of known tumor types and histological subtypes.
CancerTYPE IDs database includes 2,206 tumors from multiple tumor banks, selected to provide broader and deeper representation of the heterogeneity of tumors. The 92-gene assay does not overlap with IHC markers, providing complementary data to standard tumor diagnosis.
CancerTYPE ID uses real-time reverse transcription polymerase chain reaction (RT-PCR). A very low copy number of RNA molecules can be detected, thus reducing the sample tissue required for testing. Testing is conducted and results are generated at bioTheranostics' CAP-accredited, CLIA-certified laboratory.
For more information, click here.
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(1) Don't forget to do your Holiday shopping by clicking on the Amazon.com links on our Home Page, by clicking here or by clicking on any link on our Books pages.
(2) The Stains and CD Markers chapters have been changed so each now appears on one page, instead of being divided into separate pages. We are also updating these topics more frequently.
Visit and follow our Blog to see recent updates to the website.
(1) Don't forget to do your Holiday shopping by clicking on the Amazon.com links on our Home Page, by clicking here or by clicking on any link on our Books pages.
(2) The Stains and CD Markers chapters have been changed so each now appears on one page, instead of being divided into separate pages. We are also updating these topics more frequently.
Visit and follow our Blog to see recent updates to the website.
Case #225
Clinical history:
A 73 year old man had a 4 month history of progressive right leg swelling with tender nodules, which began with a splinter injury while chopping firewood. Past medical history is remarkable for treated non-Hodgkins lymphoma, diagnosed 2 years previously. The nodules were biopsied.
Clinical image:
Microscopic images:
H&E
PAS
GMS
What is your diagnosis?
Click here for diagnosis and discussion:
Diagnosis: Prototheca wickerhamii
Discussion:
The organism was cultured on blood, chocolate and Sabourauds dextrose agar. After 2 days, the organism appeared as yeast-like colonies on all media.
Microscopic examination of the culture plates showed multiple spherical organisms in clusters with thick walls. The organism cultured on the agar plates was inoculated onto an API 20 C AUX strip (bioMerieux Inc., Durham, NC, USA), used to identify the most frequently encountered yeasts. Based on the results of the carbohydrate assimilation tests on this panel, the organism was identified as Prototheca wickerhamii.
Prototheca was first recognized as a human pathogen in 1964 (J Clin Microbiol 2004;42:4907). 2 species are associated with human disease P. wickerhamii and P. zopfii. These fungi-like organisms are actually aerobic, achlorophyllous, algae-like, unicellular organisms commonly present in water, sewage and soil. Human infection is rare, and usually occurs via trauma or contaminated water and involves the face or exposed extremities. Patients are often immunocompromised (Arch Pathol Lab Med 2011;135:941, Am J Surg Pathol 1994;18:1261). Patients present with erythematous plaques, nodules or superficial ulcers.
Histologically, there are necrotizing granulomas containing spherical organisms with central basophilia, internal septation and double layered cell walls. There may also be multiple endospores 2 - 4 microns in size. Green algae may appear similar but contain abundant cytoplasmic starch granules (Arch Pathol Lab Med 1978;102:353).
Recommended treatment is surgery or Amphotericin B for disseminated disease. In this case, the patient had rapid progression of his disease in a lymphangiitic pattern. He was admitted to the hospital with a plan to either debride or amputate the leg but died before surgery began. No autopsy was performed.
