title: Bronchial carcinoid tumor with crystalloid cytoplasmic inclusions.
abstract: We report a bronchial carcinoid tumor with distinctive, cytoplasmic, rod-shaped crystalloid inclusions that were visible by light microscopy. These cytoplasmic structures were immunoreactive with antibodies against chromogranin A and synaptophysin in paraffin-embedded tissue. Ultrastructural studies showed them to be paracrystalline in nature and located within lysosomes. This case highlights an interesting, and potentially confusing, histologic manifestation in an otherwise typical bronchial carcinoid tumor.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minn. 55905, USA.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Grogg
authors.forename: Chandrashekar
authors.initials: C
authors.lastname: Padmalatha
authors.forename: Kevin O
authors.initials: KO
authors.lastname: Leslie
mesh_terms: D001984:Bronchial Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D002276:Carcinoid Tumor / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D003460:Crystallization; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D002479:Inclusion Bodies; D008875:Middle Aged