Tumefactive appearance of peripheral nerve involvement in hematologic malignancies: a new imaging association.
OBJECTIVE
In neurolymphomatosis (NL), the affected nerves are typically described to be enlarged and hyperintense on T2W MR sequences and to avidly enhance on gadolinium-enhanced T1WI. This pattern is highly non-specific. We recently became aware of a "tumefactive pattern" of NL, neuroleukemiosis (NLK) and neuroplasmacytoma (NPLC), which we believe is exclusive to hematologic diseases affecting peripheral nerves.


METHODS
We defined a "tumefactive" appearance as complex, fusiform, hyperintense on T2WI, circumferential tumor masses encasing the involved peripheral nerves. The nerves appear to be infiltrated by the tumor. Both structures show varying levels of homogenous enhancement. We reviewed our series of 52 cases of NL in search of this pattern; two extra outside cases of NL, three cases of NLK, and one case of NPLC were added to the series.


RESULTS
We identified 20 tumefactive lesions in 18 patients (14 NL, three NLK, one NPLC). The brachial plexus (n = 7) was most commonly affected, followed by the sciatic nerve (n = 6) and lumbosacral plexus (n = 3). Four patients had involvement of other nerves. All were proven by biopsy: the diagnosis was high-grade lymphoma (n = 12), low-grade lymphoma (n = 3), acute leukemia (n = 2), and plasmacytoma (n = 1).


CONCLUSIONS
We present a new imaging pattern of "tumefactive" neurolymphomatosis, neuroleukemiosis, or neuroplasmacytoma in a series of 18 cases. We believe this pattern is associated with hematologic diseases directly involving the peripheral nerves. Knowledge of this association can provide a clue to clinicians in establishing the correct diagnosis. Bearing in mind that tumefactive NL, NLK, and NPLC is a newly introduced imaging pattern, we still recommend to biopsy patients with suspicion of a malignancy.
Department of Neurosurgery, Mayo Clinic, Gonda 8-214, Rochester, Minnesota, 55905, USA.
Stepan
S
Capek
Marie-Noëlle
MN
Hébert-Blouin
Ross C
RC
Puffer
Carlo
C
Martinoli
Matthew A
MA
Frick
Kimberly K
KK
Amrami
Robert J
RJ
Spinner
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019337:Hematologic Neoplasms / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010525:Peripheral Nerves / Q000473:pathology*; D010524:Peripheral Nervous System Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity