Lymphoma - 71-year-old female who presented with swelling on the right side of the neck

History at Initial Staging
71-year-old female who presented with swelling on the right side of the neck. Right tonsillar biopsy demonstrated malignant lymphoma, large B cell type.

CT Findings
CT of neck, chest, abdomen and pelvis demonstrated right tonsil soft tissue mass with right-sided lymphadenopathy. There were also borderline size lymph nodes in the iliac chain bilaterally and in the right inguinal fossa. They were considered nonspecific.

Initial PET Findings
In the neck, there is a 2 cm rather intense uptake in the right tonsil associated with two adjacent lymph nodes. One is located anterior to the carotid sheath and a smaller second one is in the posterior cervical triangle. The patient has corresponding abnormalities on the CT scan. No other abnormal uptake is present in the neck.

In the mediastinum, there is a 1 cm very intense area of uptake in the right paratracheal space, highly suspicious for lymphoma. Retrospectively, a discrete lymph node cannot be definitely seen with confidence. No other abnormal uptake is seen in the chest. In the right lower pelvis, there is a 1.5 cm intense uptake just anterior to the right acetabulum. This corresponds to a soft tissue mass seen on the CT exam. This is also consistent with lymphoma. No other abnormal uptake is present.

Dosage
15.1 mCi FDG

History at Re-staging (6 months)
71-year-old female diagnosed with large B cell type lymphoma in her right tonsil 6 months prior. Patient referred for re-staging, 6 weeks post chemotherapy.

CT Findings
Follow-up CT of the chest, abdomen and pelvis showed interval resolution of the right tonsillar mass and adenopathy. There were no suspicious masses or adenopathy in the remaining body.

Re-staging PET Findings
The neck is now normal. The right tonsillar and cervical lymph node hypermetabolic activities have both been resolved. Abdomen and pelvis are also within normal limits. Right pelvic lymphadenopathy uptake is no longer present. The patient still had numerous mediastinal and bilateral hilar hypermetabolic activity, consistent with residual lymphoma. The largest and most hypermetabolic activity is in the right paratracheal space measuring 1.5 cm. The mediastinal activity has actually progressed from prior exam. There is also focal hypermetabolic activity corresponding to subtle infiltrate seen in the medial segment of the right middle lobe.

Dosage
14.5 mCi FDG

Imaging
CTI REVEAL XL

Courtesy of
Thompson Cancer Survival Center