17
Table 6. Histopathological Criteria for the Diagnosis of HP
(Other than "Hot-Tub Lung"
a
)
Matter Typical Sources HP "Disease"
Nonfibrotic HP (cellular HP)
2. Cellular bronchiolitis:
• Lymphocyte-
predominant
(lymphs > plasma cells)
with no more than
focal peribronchiolar
lymphoid aggregates
with germinal centers
• ±Organizing pneumonia
pattern with Masson
bodies
• ±Foamy macrophages in
terminal air spaces
2. Cellular bronchiolitis:
• Lymphocyte-predominant
(lymphs > plasma cells)
with no more than focal
peribronchiolar lymphoid
aggregates with germinal
centers
• ±Organizing pneumonia
pattern with Masson
bodies
• ±Foamy macrophages in
terminal air spaces and
Absence of features in
any biopsy site to suggest
an alternative diagnosis:
• Plasma cells > lymphs
• Extensive lymphoid
hyperplasia
• Extensive well-formed
sarcoidal granulomas
and/or necrotizing
granulomas
• Aspirated particulates
Absence of features in any
biopsy site to suggest an
alternative diagnosis:
• Plasma cells > lymphs
• Extensive lymphoid
hyperplasia
• Extensive well-formed
sarcoidal granulomas and/
or necrotizing granulomas
• Aspirated particulates
3. Poorly formed
nonnecrotizing
granulomas:
b
• Loose clusters of
epithelioid cells and/
or multinucleated giant
cells ± intracytoplasmic
inclusions
• Situated in
peribronchiolar
interstitium, terminal
air spaces, and/or
organizing pneumonia
(Masson bodies) and
Absence of features in any
biopsy site to suggest an
alternative diagnosis:
• Plasma cells > lymphs
• Extensive lymphoid
hyperplasia
• Extensive well-formed
sarcoidal granulomas
and/or necrotizing
granulomas
• Aspirated particulates
(cont'd)
