44-year-old female exhibited a painless enlargement of axillary and supraclavicular lymph nodes. Serum calcium levels were slightly increased above the normal range. An enlarged axillary lymph node was excised.
- The entire lymph node is permeated by non-caseating, partly confluent granulomas consisting of compact collections of epitheloid histiocytes that are on occasion, intermixed with multi-nucleated giant cells.
- Some granulomas exhibit a distinct fibrosis.
Per definition, sarcoidosis is a diagnosis of exclusion and other diseases causing a granulomatous reaction (e.g. tuberculosis) must be actively sought (acid-fast stain). Beware; tuberculosis may also produce non-caseating granulomas.