A 62­ year-­old male was admitted to the hospital complaining of shortness of breath. His chest X­-ray showed a rightsided cavitary lesions. His medical history indicated he had smoked one pack of cigarettes per day for past 40 years and has had cavitary tuberculosis in about 20 years ago. Recently he is receiving cytostatic therapy for his acute myeloblastic leukaemia. A biopsy specimen of the lung was obtained. Biopsy from lesion shows tubular eukaryotic septated hyphae with diameter of 5­10 μm that are infiltrating the lung tissue. Culture on Saboraud’ media shows conidia with spores in radiating columns. Which is the most like cause of the findings?

The disease is systemic - affecting lungs. Organism has septated hyphae with conidia. Is there any other possibilities for the disease?

  • $\begingroup$ Any more information about the pathology? IPA? Sloughing, consolidation? IF we had a little more info we might be able to shed more light. $\endgroup$ – Atl LED Aug 19 '13 at 19:27
  • $\begingroup$ Is the hyphae diameter really 510µm? That seems exceptionally large. Could this be the length instead? $\endgroup$ – Gossar Aug 19 '13 at 19:51

Is there any other possibilities for the disease?
Yes. At 37°C, Histoplasma capsulatum usually doesn't form hyphae. from Wikimedia Commons: histology section showing H. capsulatum with methenamine silver stain

Were the hyphae branching, like this?Histopathologic image of pulmonary invasive mycosis

If "conidia with spores in radiating columns" means the pictures below, CDC micrograph of _A. fumigatus_ with conidiaphotomicrograph from www.aspergillus.org.uk
We have enough to say that this is not a case of Histoplasma capsulatum and there is definitely another possibility for this disease.
Conidia with radiating chains of spores is pathognomonic for aspergillosis.

| improve this answer | |
  • $\begingroup$ I do not know if hyphae was branching like that. I have only the text. It is at least septated hyphea like in your picture. No information about temperature where the sample is cultured. Histoplasma capsulatum is a possibility here. $\endgroup$ – Léo Léopold Hertz 준영 Aug 19 '13 at 7:50
  • 1
    $\begingroup$ Not the temperature of the culture, the temperature of the biopsy—because the patient is still alive, you have reason to believe that the biopsy was warmer than 30°C. As explained at the previously linked site, H. capsulatum is dimorphic, growing as a mold at room temperature and as a yeast at body temperature. $\endgroup$ – Gossar Aug 19 '13 at 8:03
  • $\begingroup$ Tissue morphology Histoplasmosis: Small narrow base budding yeast cells (1-5um; 5-2um in var. duboisii) $\endgroup$ – Gossar Aug 19 '13 at 8:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.