Granuloma with irregularly-shaped central abscess (stellate abscess):
(1) lymphogranuloma venereum (LGV)
(2) tularemia
(3) cat-scratch fever (Bartonella species)
(4) fungal infection
(5) Yersinia
(6) Leishmaniasis
Granuloma with or without caseous necrosis:
(1) mycobacterial infection, including BCG and leprosy
(2) deep fungal infection (Histoplasmosis, Blastomycosis, etc)
If the histiocyte nuclei in the outer granuloma are elongated and oriented radially, then the granuloma is referred as a palisading granuloma (from its resemblance to a “palisade” or old timber fort).
A granuloma with central necrosis of any type may heal with fibrosis.
Granulomatous inflammation may also occur with:
(1) toxoplasmosis
(2) brucellosis
(3) syphilis
(4) pneumocystis
Differential diagnosis:
(1) sarcoidosis
(2) sarcodial-like reactions
