What is the appropriate work‑up for a 60‑year‑old woman with a 4‑day history of a unilateral left submental lymph node and abdominal cramping with frequent formed stools?

Work-Up for 60-Year-Old Woman with Left Submental Lymphadenopathy and GI Symptoms

This patient requires immediate contrast-enhanced CT imaging of the neck, chest, abdomen, and pelvis to evaluate the extent of lymphadenopathy and identify any underlying malignancy or systemic disease, followed by excisional lymph node biopsy if imaging reveals concerning features. 1

Initial Clinical Assessment

The combination of unilateral submental lymphadenopathy with concurrent GI symptoms (cramping and frequent formed stools) in a 60-year-old woman raises concern for systemic disease, particularly lymphoma or metastatic malignancy. The 4-day duration is relatively acute, but the specific pattern warrants thorough investigation rather than observation. 1

Critical Features to Document Immediately

• Lymph node characteristics: Size (nodes >15 mm in short axis require investigation), consistency (hard vs. rubbery), mobility, and presence of matting 1
• Systemic symptoms: Fever, night sweats, unintentional weight loss (B symptoms suggesting lymphoma), or paradoxical weight gain (which may indicate ascites or organomegaly) 1
• GI symptom details: Duration, frequency of bowel movements, presence of blood, mucus, or change in stool caliber; associated symptoms like nausea, vomiting, or early satiety 2
• Physical examination findings: Hepatosplenomegaly, additional peripheral lymphadenopathy (cervical, axillary, inguinal), abdominal masses, or ascites 1

Mandatory Laboratory Workup

Execute the following laboratory panel immediately:

• Complete blood count with differential: Assess for lymphocytosis, cytopenias, or atypical lymphocytes 1
• Comprehensive metabolic panel: Including liver function tests, renal function, and electrolytes 1
• Lactate dehydrogenase (LDH): Elevated in lymphoproliferative disorders and serves as a prognostic marker 1
• Serology: HIV, hepatitis B and C testing to rule out infectious etiologies that can cause lymphadenopathy 1
• Inflammatory markers: C-reactive protein and erythrocyte sedimentation rate 2

Imaging Protocol

Contrast-enhanced CT of the neck, chest, abdomen, and pelvis is the primary imaging modality to assess the full extent of lymphadenopathy and evaluate for intra-abdominal pathology that could explain both the lymphadenopathy and GI symptoms. 1

Key Imaging Features to Document

• Lymph node characteristics: Short-axis diameter of largest nodes, loss of fatty hilum, round rather than oval shape, heterogeneous density, or central necrosis 1
• Abdominal findings: Mesenteric lymphadenopathy, bowel wall thickening, hepatosplenomegaly, ascites, or masses 1, 3
• Size thresholds for pathologic nodes: Retrocrural nodes >6 mm, upper abdominal nodes >10 mm, pelvic nodes >15 mm 3

The CT will help differentiate between localized disease (isolated submental node) versus systemic lymphadenopathy, and identify any primary intra-abdominal pathology (gastric, pancreatic, or colonic malignancy) that could cause both regional lymph node drainage and GI symptoms. 2, 1

Tissue Diagnosis Strategy

Do not delay biopsy in favor of observation if the lymph node is >15 mm or has concerning imaging features. 1 The approach depends on node size and imaging characteristics:

For Nodes >15 mm or With Concerning Features

• Excisional biopsy is preferred over fine-needle aspiration, as it provides superior tissue architecture assessment critical for lymphoma diagnosis and subtyping 2, 1
• The specimen must be sent to a reference hematopathology laboratory for morphological interpretation, immunophenotyping, flow cytometry, and molecular studies 4
• If excisional biopsy is not feasible, core needle biopsy is acceptable but FNA alone is insufficient 2

For Nodes ≤15 mm With Benign Features

• Clinical observation with repeat imaging in 4-6 weeks may be considered 1
• However, given the concurrent GI symptoms in this patient, proceeding directly to biopsy is reasonable to avoid diagnostic delay 1

Gastrointestinal Evaluation

Given the prominent GI symptoms, additional workup should include:

• Stool studies: Fecal calprotectin, stool culture, ova and parasites, Clostridioides difficile toxin 2
• Colonoscopy with biopsy: If CT reveals colonic wall thickening, masses, or if symptoms persist, to evaluate for inflammatory bowel disease, infectious colitis, or malignancy 2
• Upper endoscopy: Consider if there are upper GI symptoms or if gastric pathology is suspected on imaging, as gastric lymphoma can present with lymphadenopathy and GI symptoms 2

Differential Diagnosis Framework

Malignant Causes (Priority Given Age and Presentation)

• Lymphoma (Hodgkin or non-Hodgkin): Submental node with systemic symptoms; GI involvement can cause cramping and altered bowel habits 2, 1
• Metastatic disease: Head and neck primary (oral cavity, oropharynx), thyroid, or distant primary with nodal metastases 1
• Gastrointestinal malignancy: Gastric, pancreatic, or colorectal cancer with nodal spread and primary GI symptoms 2

Infectious/Inflammatory Causes

• Viral infection: Epstein-Barr virus, cytomegalovirus causing reactive lymphadenopathy 1
• Bacterial infection: Dental abscess, submandibular gland infection with reactive nodes 1
• Inflammatory bowel disease: Crohn's disease or ulcerative colitis can cause mesenteric lymphadenopathy and GI symptoms 2, 5

Other Considerations

• Reactive lymphadenopathy: From local infection or inflammation, though unilateral presentation is less typical 6
• Autoimmune conditions: Sarcoidosis, though usually presents with bilateral lymphadenopathy 1

Management Algorithm

1. Immediate (Day 1-2): Obtain laboratory studies and contrast-enhanced CT neck/chest/abdomen/pelvis 1

2. Based on CT findings:

   • If node >15 mm or concerning features: Proceed directly to excisional biopsy 1
   • If extensive abdominal lymphadenopathy: Consider CT-guided biopsy of most accessible node 1
   • If isolated small node (<15 mm) with benign features: May observe with repeat imaging in 4-6 weeks, but given GI symptoms, lower threshold for biopsy 1

3. If CT reveals GI pathology: Coordinate endoscopic evaluation (upper or lower) with biopsy 2

4. If biopsy confirms lymphoma: Complete staging workup including PET/CT, bone marrow biopsy if indicated, and referral to hematology-oncology 2

Critical Pitfalls to Avoid

• Do not rely on FNA alone to exclude lymphoma; excisional biopsy provides definitive diagnosis 2, 1
• Do not empirically treat with antibiotics without clear evidence of bacterial infection, as this delays diagnosis and can mask underlying malignancy 4
• Do not assume reactive lymphadenopathy in a 60-year-old with persistent nodes; age increases malignancy risk 1
• Do not ignore the GI symptoms as coincidental; they may represent systemic disease or a primary GI malignancy causing nodal spread 2, 1
• Do not delay imaging waiting for spontaneous resolution; 4 days is sufficient to warrant investigation in this age group with this presentation 1