Table 2.
Positron emission tomography–computed tomography abnormalities and diagnostic tests in patients with a definite final diagnosis
| Final Diagnosis (Number of patients) | PET-CT findings | Diagnostic test |
|---|---|---|
| NIID - CTD and Vasculitis (7) | ||
| Systemic Lupus Erythematosus (2) | Metabolically active cervical, mediastinal and hilar LNE Metabolically active cervical, axillary, mediastinal and abdominal LNE |
Fulfilled SLICC criteria Fulfilled SLICC criteria; renal biopsy - Class 4 lupus nephritis |
| Renal-limited vasculitis (2) | No abnormalities detected Minimal ascites |
Renal biopsy – focal segmental glomerulosclerosis with granuloma Renal biopsy - diffuse proliferative glomerulonephritis |
| Primary cutaneous small -vessel vasculitis (1) | Metabolically active fascial thickening in the retroperitoneal region [Figure 1] | Skin biopsy – vasculitis; ANCA negative; retroperitoneal fascial biopsy - normal |
| Undifferentiated CTD (1) | Mild hepatosplenomegaly | ANA positive, nerve biopsy – neurogenic atrophy |
| Granulomatosis with polyangiitis (1) | Metabolically active para-aortic, aorto-caval and iliac lymph nodes [Figure 2] | C-ANCA positive; renal biopsy – vasculitis with granuloma |
| Other NIID (9) | ||
| Adult-onset Still’s disease (5) | Cervical and axillary LNE, hepatosplenomegaly Metabolically active axillary LNE Axillary, mediastinal, abdominal LNE, hepatosplenomegaly Metabolically active cervical and thoracic LNE, hepatosplenomegaly No abnormalities |
All fulfilled Yamaguchi criteria (two patients underwent lymph node biopsy which were reported as normal) |
| Sarcoidosis (2) | Metabolically active thoracic and abdominal LNE, hepatosplenomegaly Axillary, mediastinal and abdominal LNE, hepatosplenomegaly |
Liver biopsy – non-caseating granuloma Response to treatment (lymph node and liver biopsy – inconclusive) |
| Kikuchi’s disease (1) | Metabolically active axillary and mediastinal LNE | Mediastinal lymph node biopsy (axillary lymph node biopsy – inconclusive) |
| Inflammatory myositis (1) | Metabolically active muscle inflammation | Muscle biopsy |
| Infectious Diseases (10) | ||
| Tuberculous lymphadenitis (2) | Metabolically active mediastinal LNE Metabolically active mediastinal and hilar LNE |
Mediastinal lymph node biopsy Mediastinal lymph node biopsy |
| Disseminated tuberculosis (4) | Metabolically active mediastinal, hilar LNE, omental, and mesenteric thickening; dilated jejunal loops, mesenteric adhesions Metabolically active mediastinal, hilar, periportal, retroperitoneal LNE, right psoas abscess& Metabolically active mediastinal, hilar LNE, pulmonary nodules, pleural thickening Metabolically active mediastinal, hilar, peri-esophageal LNE, pulmonary infiltrates |
Omental biopsy Mediastinal node biopsy Transbronchial lung biopsy Transbronchial lung biopsy |
| Pericardial tuberculosis (1) | Pericardial effusion; no metabolically active focus | Pericardial biopsy |
| Adrenal tuberculosis (1) | Metabolically active bilateral adrenal glands | CT-guided adrenal biopsy |
| Tuberculous enteritis (1) | Colonic wall thickening | Colonoscopy and terminal ileum biopsy |
| Melioidosis (1) | Metabolically active splenic collection and bilateral axillary LNE | Splenic abscess aspiration |
| Malignancy (4) | ||
| Hodgkin’s lymphoma (1) | Metabolically active mediastinal, internal iliac, para-aortic LNE and hepatosplenomegaly | Laparoscopic liver and spleen biopsy (this patient had mildly enlared lymph nodes which were not amenable for biopsy) |
| Non-Hodgkin’s lymphoma (1) | Metabolically active pelvic mass lesion | Pelvic mass lesion biopsy |
| Colonic myofibroblastic tumor (1) | Metabolically active descending colon mass lesion [Figure 3] | Colonic mass lesion biopsy |
| Metastatic Carcinoma prostate (1) | Disseminated sclerotic bone metastases; diffuse increased uptake in prostate gland | Bone marrow biopsy – metastatic adenocarcinoma, elevated Prostate Specific Antigen |
| Miscellaneous (2) | ||
| AIHA** (1) | Metabolically active diffuse marrow hyperplasia | Bone marrow biopsy and Direct Coomb’s Test |
| Mesangioproliferative glomerulonephritis (1) | Minimal bilateral pleural effusion | Renal biopsy |
CTD: Connective tissue disease; LNE: Lymph Node Enlargement, SLICC: Systemic Lupus International Collaborating Clinics, AIHA: Autoimmune hemolytic anemia, PET-CT: Positron emission tomography–computed tomography, NIID: Noninfectious inflammatory disease