Table 2 Spindle cell proliferations with inflammatory infiltrate: differential diagnoses

Middle age to elderly; no gender predilection reported for lymph node; 5:3 female predominance for splenic cases (Ma et al., 2013)

Variable: no symptoms; previous signs of infectious process; presence of general symptoms (ca. 60%)

Lymph nodes and spleen more common; may be extranodal

May be positive: CD68, smooth muscle actin;

Negative: ALK and dendritic cell markers; microorganisms may be found (mycobacteria, lues, fungi, EBV more frequent in spleen and liver)

Favorable after treatment; no recurrence or distant metastases

Around 30 years;

Children and young adults preferred;

M equal to F

15–30% general symptoms: fever, weight loss, anemia, thrombocytosis, hipergammaglobulinemia, elevated erythrocyte sedimentation rate

Lung, soft tissue of abdomen, pelvis and retroperitoneum

Spindle cells frequently positive for smooth muscle actin; ALK positive ~50–60%;

May be EBV+; Negative for CD21, CD23, CD35, CNA42

Local recurrence (10–25%); distant metastases (<5%)

Around 40y;Female predominate

Assymptomatic, abdominal pain, fadigue

Spleen, liver or both

Positive for CD21, CD23, CD35, CNA42; Negative for ALK; EBV+

Local recurrence and distant metastases less frequent than other FDCT (>40% recurrence and >25% metastases lung, lymph node, liver)