Cytologic diagnosis of cat scratch disease (CSD) by fine‐needle aspiration

Abstract

Cat scratch disease (CSD) is usually a benign, self-limited lymphadenitis, characterized by suppurative granulomas. It can, however, produce a wide spectrum of clinical symptoms and cytologic changes and be the source of diagnostic dilemmas. Identification of pleomorphic bacilli (PB) with silver impregnation stains aids in the diagnosis, but this has not been well documented in cytologic preparations or in cases without the classic morphologic changes. We reviewed 13 aspirations from eight patients (aged 13-36 yr) occurring over a 15 mo time period, all clinically or cytologically suspicious for CSD. Sites included: axilla (6), parotid (3), epitrochlear (1), neck (1), submental (1), and intraclavicular (1) nodes. Neoplasia was initially suspected clinically in 38% of the cases. All but two patients had cat exposure on subsequent interview. The cytologic differential included bacterial abscess and lymphoproliferative disorders in 31%. Neither granulomas nor suppurative inflammation were seen in all cases. Changes included: granulomas (77%), PMNs (62%), dispersed epithelioid histiocytes (46%), and suppurative granulomas (38%). A modified silver stain (Modified Steiner, Sigma Diagnostics, St. Louis, MO) was performed on all specimens. Silver positive organisms were seen in 69% of cases and were not limited to those preparations with suppurative granulomas. Fine-needle aspiration biopsy (FNAB) is an effective method for diagnosing CSD despite its heterogeneous appearance; and, when combined with clinical information and silver staining, may obviate the need for excision.

Fine-Needle Aspiration Biopsy of Lymph Nodes in the Modern Era

“…It is a self-limited process that is most often sampled by FNA biopsy due to a clinical impression of neoplasia. 50 FNA smears from catscratch disease generally shows a mixed population of lymphocytes, neutrophils, tingible body macrophages, and lymphohistiocytic aggregates. Although seen in a minority of cases, the most distinctive finding in cat-scratch disease is the presence of suppurative granulomas composed of aggregates of epithelioid histiocytes arranged in a peripheral palisade with central neutrophils (Fig.…”

“…Warthin-Starry stain may occasionally demonstrate B henselae in cases of cat-scratch disease. 50 Other histochemical stains for bacteria generally show a great deal of nonspecific staining in cases of suppurative lymphadenitis. Since most bacteria grow quickly in culture, stains such as Brown and Brenn or Brown and Hopps are not likely to add to the diagnosis.…”

“…In some cases, obvious granulomas are not seen, but the combination of reactive lymphoid cells, neutrophils, and individually dispersed histiocytes can suggest the diagnosis. The causative organism, Bartonella henselae, 50 Serologic studies may also be helpful. Stastny et al 52 described the cytomorphologic findings in cat-scratch disease as appearing in 3 stages, each of which may be confused with other processes.…”

Fine Needle Aspiration Cytology of Kikuchi-Fujimoto’s Disease: A Report of 2 Cases with Emphasis on Cytologic Features and Differential Diagnosis

“…FNA from toxoplasma lymphadenitis samples usually reveals the presence of epithelioid cell granulomas in the background of a polymorphous lymphoid population and histiocytes, and absence of necrosis, suppurative changes and giant cells [15,16,17]. Cytologic smears from lymph node FNA in cat scratch disease generally reveal granulomas with peripherally palisading epithelioid histiocytes and centrally located neutrophils (suppurative granulomas) along with a polymorphous population of lymphoid cells [18,19]. Herpes simplex-associated lymphadenitis shows, in addition to the presence of histiocytes and necrotic debris, frequent neutrophils and absence of a polymorphous population of histiocytes.…”

Fine needle aspiration of lymph nodes.

“…Biopsy of persistent reactive lymphadenopathy where the cause has not been defined after needle aspiration and other investigations will allow the diagnosis of rarer lymph node pathologies such as sinus histiocytosis with massive lymphadenopathy, 8 histiocytic necrotising lymphadenitis, 9 cat scratch disease, 10 and Kimura's disease. 11 The cytology of these lesions may be distinctive but since they are uncommonly seen they may not be so easily diagnosed on a prospective basis.…”