What are the next steps and referrals for a patient with confirmed mycosis fungoides (cutaneous T-cell lymphoma) with nodal affection and potential systemic involvement, after requesting a Positron Emission Tomography (PET) or Computed Tomography (CT) scan with contrast and referring to oncology/hematology and general surgery?

Additional Referrals for Mycosis Fungoides with Nodal and Systemic Involvement

Beyond oncology/hematology and general surgery, you should consider referring to radiation oncology for potential total skin electron beam therapy or localized radiotherapy, and to interventional radiology if lymph node biopsy is needed for pathologic confirmation of nodal involvement. 1

Essential Multidisciplinary Team Members

Radiation Oncology

• Radiation oncology consultation is critical for advanced mycosis fungoides (stage IIB and above) with nodal involvement, as radiotherapy is highly effective for this radiosensitive tumor 1
• Total skin electron beam (TSEB) therapy achieves response rates of 52-59% in stage IB disease and is a first-line option for stage IIB disease 1
• Localized superficial radiotherapy can be used for individual tumors or nodal masses, with the advantage that closely adjacent fields can be retreated due to low doses used 1

Interventional Radiology

• Lymph node biopsy (excisional preferred, or core/FNA with flow cytometry and TCR gene analysis) should be performed when nodal involvement affects global response assessment 1
• Specifically indicated when: (1) new lymphadenopathy develops in a patient without baseline nodal disease, or (2) persistent lymph nodes >1 cm in short axis remain after treatment in patients with known lymphomatous involvement 1
• Physical examination alone is unreliable for determining lymph node involvement, making pathologic confirmation essential 1

Bone Marrow Biopsy Consideration

• Bone marrow biopsy and aspiration should be performed in mycosis fungoides with intermediate or aggressive clinical behavior or advanced stage disease (stage IIB and above) 2
• Not routinely required in early-stage indolent mycosis fungoides unless other staging assessments suggest systemic involvement 2
• Bone marrow is among the common sites of extracutaneous spread in advanced disease 3

Imaging Coordination

CT vs PET-CT Decision

• CT with contrast is recommended as the baseline imaging modality for full TNMB staging in advanced disease 1
• PET-CT is not routinely recommended for mycosis fungoides/Sézary syndrome due to: limited data in CTCL, difficulty distinguishing inflammation from lymphoma, doubled radiation exposure, and high cost 1
• However, PET-CT is essential for CTCLs with predominantly subcutaneous presentation (not typical mycosis fungoides) 2
• The false-positive rate with PET exceeds 20%, leading to unnecessary investigations 4

Repeat Imaging Triggers

• For advanced disease (TNMB greater than T1-2N0M0B0-1), repeat CT should be performed at: time of partial/complete response in skin, any suspicion of new/progressive nodal or visceral disease, and end of study 1
• MRI is an alternative to CT that provides accurate nodal and visceral information without radiation exposure, though costly and limited in renal dysfunction 1

Common Pitfalls to Avoid

• Do not rely on physical examination alone for nodal assessment—it is unreliable even for peripheral nodes, and inadequate for internal organs 1
• Avoid routine surveillance PET-CT—it has not been validated for mycosis fungoides and adds unnecessary radiation burden to patients who will undergo multiple scans over their lifetime 1
• Do not skip pathologic confirmation of suspicious nodes—imaging alone (even PET-CT) cannot definitively establish lymphomatous involvement versus reactive changes 1
• Ensure adequate staging before treatment decisions—extracutaneous involvement dramatically worsens prognosis (5-year survival drops from 80% in early disease to 15-40% in stage IVA and 0-15% in stage IVB) 2

Prognosis Context for Referral Urgency

• Median survival for extracutaneous mycosis fungoides is only 14.5 months overall 5
• Patients achieving complete response have median survival of 21 months versus 8 months for non-responders 5
• Early multidisciplinary coordination is essential given the poor prognosis and need for aggressive multimodal therapy in advanced disease 2, 5