Extrarenal rhabdoid tumor presented with an immobile arm in a one-year-old boy.

Infants with an immobile arm may be easily overlooked in primary care settings. Differential diagnoses include injuries, infections, neuropathies, ischemia and rarely, neoplasms. We report the case of a one-year-old boy with weakness in his left arm after minor trauma with a diagnosis of brachial plexus palsy initially. After rehabilitation for 2months, his weakness progressed to unsteady gait and quadriparesis. MRI revealed a huge solid tumor in the left supraclavicular fossa, which also involved the left brachial plexus, upper thoracic cavity, and left paravertebral space with invasion into the spinal canal. Microscopically, the medium-large polygonal tumor cells had an eccentric eosinophilic cytoplasm and immunostaining showed a loss of nuclear INI1 expression. Array comparative genomic hybridization of the tumor tissue confirmed a segmental deletion at chromosome region 22q11.23 involving the SMARCB1 gene. The final diagnosis was cervical paravertebral malignant rhabdoid tumor with intraspinal epidural and intradural invasion, a rare case of extrarenal extracranial rhabdoid tumor (ERRT). The intraspinal part of the tumor was resected followed by interval-compressed chemotherapy with vincristine-doxorubicin-cyclophosphamide alternating with ifosfamide-etoposide (VDC/IE). The tumor showed very good partial response to four cycles of chemotherapy with gradual recovery of neurological symptoms. ERRT is a very rare and aggressive tumor that mainly occurs in infants and children and may manifest with vague neurological symptoms when it involves the spinal cord and/or peripheral nerves. A neoplasm such as ERRT originating from or involving the brachial plexus should be considered in the differential diagnosis of an immobile arm in infancy.

CTNNB1 Mutations and Estrogen Receptor Expression in Neuromuscular Choristoma and Its Associated Fibromatosis.

Neuromuscular choristoma (NMC) is a very rare, developmental malformation characterized by the endoneurial intercalation of mature muscle fibers among peripheral nerve fibers. NMC typically arises in the major proximal peripheral nerves, most commonly the sciatic nerve, and may involve the lumbosacral and brachial plexus. Patients present clinically with progressive neuropathy or plexopathy. NMC is strongly associated with development of a fibromatosis, histologically identical to conventional desmoid-type fibromatosis (NMC-fibromatosis). The development of NMC-fibromatosis is often precipitated by iatrogenic trauma (ie, biopsy). Desmoid-type fibromatosis is characterized by CTNNB1 exon 3 mutations, which result in aberrant nuclear ß-catenin localization and dysregulated canonical Wnt signaling. In contrast, the pathogenesis of NMC and NMC-fibromatosis is unknown. Desmoid-type fibromatosis expresses estrogen receptors (ER), specifically the ER-beta isoform (ERß), and endocrine therapies may be used in surgically unresectable cases. In contrast, the ER expression profile of NMC-fibromatosis is unknown. We evaluated a series of NMC and NMC-fibromatosis for CTNNB1 mutations, ß-catenin expression, and ER isoform expression. Five NMCs occurred in 2 female and 3 male patients (median age: 14 y, range <1 to 42 y), as masses involving the sciatic nerve (N=4) or brachial plexus (N=1). Four (of 5) NMCs had CTNNB1 mutations: 3 c.134 C>T (p.S45F) and 1 c.121 A>G (p.T41A). Four patients subsequently developed NMC-fibromatosis, and all 4 cases contained CTNNB1 mutations, including 1 p.T41A and 3 p.S45F mutations. In 3 patients, the NMC and NMC-fibromatosis had identical CTNNB1 mutations. Only 1 NMC had no detectable CTNNB1 mutation; however, the patient's subsequent NMC-fibromatosis had a CTNNB1 p.T41A mutation. All NMC and NMC-fibromatosis showed aberrant nuclear localization of ß-catenin, nuclear ERß expression, and no ERα expression. The presence of CTNNB1 mutations both in NMC and NMC-fibromatosis may be a shared molecular genetic abnormality underlying their pathogenesis.

Surgical and postpartum hereditary brachial plexus attacks and prophylactic immunotherapy.

INTRODUCTION: Surgery and childbirth can trigger attacks of hereditary brachial plexus neuropathy (HBPN), and inflammation was suggested as a component of the pathogenesis. METHODS: HBPN patients who underwent surgery or parturition from January 1, 1996 to December 31, 2009 were studied. RESULTS: Twenty-five HBPN patients underwent 48 surgeries or parturitions. Seventeen patients (68%) had attacks, including 13 periprocedural and 7 postpartum by varied anesthesia types. Three patients who had 8 earlier combined attacks (after thyroidectomy, laminectomy, and Caesarean section) were given prophylactic immunosuppressive therapy (corticosteroids ± immunoglobulin). None suffered postoperative attacks, which is uncharacteristic of their prior experience. Five had perioperative attacks as their first HBPN manifestation. Median follow-up was 11 months (3-48 months). Attacks occurred in the operated limb (n = 6) or distant (n = 7) to surgical sites. All attacks interfered with daily living, with frequent incomplete recovery. Five patients had a SEPT9 mutation. CONCLUSIONS: Corticosteroids may prevent parturition and surgical HBPN attacks in some patients. Diverse surgeries, anesthesia, and childbirth frequently trigger HBPN attacks.

[Effect of the heat shock protein 27 on NOS expression of spinal cord anterior hornmotoneurons after brachial plexus avulsion].

AIM: To observe the effect of heat shock protein 27 (Hsp27) on nitric oxide synthase (NOS) of spinal cord anterior horn after brachial plexus roots avulsion. METHODS: Sixty male adult Wistar rats were divided into control and experiment groups at random. The experiment group subjected to heat shock under 45 degrees C for 15 min, and maintained under 42 degrees C for 20 min subsequently. After recovering 24 h under the room temperature, the nerves of brachial plexus were avulsion with microhemostatic forcep. In a span from 12 h to 7 d, these animals were killed at different time. But the control group only received the surgery of the nerve roots of brachial plexus avulsion. The freeze sections of spinal cord were stained by NADPH-d histochemistry, HSP27 immunohistochemical. RESULTS: (1) In experiment group, the motoneuron began to express NOS abundantly at 12 h after avulsion (A=0.13625). Then the NOS-positive neurons declined quickly, but in control group, the motoneuron began to express NOS at the 5th day after lesion. (2) Hsp27 begin to show the peak at 1 d in experiment and control groups, but the experiment group were more strong than the control group. CONCLUSION: Hsp27 inhibited NOS of motoneuron after avulsion and brought into full play the cytoprotection.

Desmoid-type fibromatoses involving the brachial plexus: treatment options and assessment of c-KIT mutational status.

OBJECT: Desmoid-type fibromatoses are a locally invasive soft-tissue lesion that is most commonly encountered in abdominal sites. The tumor also affects head and neck areas, particularly the supraclavicular region, where it may encase and distort the brachial plexus and compromise neurovascular structures. Neurosurgeons may be called on to treat desmoid-type fibromatoses in these sites. The authors describe their experience in treating four patients with desmoid-type fibromatoses involving the brachial plexus and report the results of immunohistochemical analysis of the tumors. METHODS: Gross-total excision with nerve sparing was the first-line therapy of choice, although the surgery was challenging. Intraoperative identification of the site of tumor origin from musculoaponeurotic tissues by the neurosurgeon was necessary in two of the four cases to achieve a correct frozen section or final pathological diagnosis. Immunostaining for c-KIT (CD117) was undertaken in all cases in light of a previous report of positive CD117 immunoreactivity in abdominal desmoid-type fibromatoses. All four tumors manifested weak focal immunostaining for c-KIT. One of the patients was given adjuvant imatinib mesylate therapy, with limited success. Subsequent polymerase chain reaction testing revealed that three of the four tumors manifested a single base pair change in exon 10 of the c-KIT gene (A to C in two cases and A to G in one case). There was local recurrence in three patients, despite gross-total excision. With the combination of surgery and radiation therapy, local disease control was achieved in three of the four patients. CONCLUSIONS: This represents the first report of c-KIT sequencing in desmoid-type fibromatoses and suggests a possible biological basis for continuing to explore the use of adjuvant imatinib mesylate therapy.

[Recurrent familial brachial plexopathy as the only clinical expression of neuropathy with susceptibility to pressure]. / Plexopatía braquial recurrente familiar como única expresión clínica de una neuropatía con susceptibilidad a la presión.

We report a family with hereditary neuropathy with liability to pressure palsies (HNPP) and chromosome 17p11.2 deletion. This family exhibits a peculiar phenotype consisting in recurrent brachial plexopathy episodes. This phenotype has to be distinguished from hereditary neuralgic amyotrophy on clinical grounds. Although the incidence of brachial plexopathy on HNPP is relatively high it is unusual as the sole symptom of the disease. It is noteworthy that in the six published families with this peculiar phenotype most of the acute episodes became evident after sleep. A greater liability of the plexus and a greater vulnerability to mechanical factors during sleep hours are the suggested mechanisms to explain this rare clinical onset. Recurrent painless brachial plexopathy when associated to generalized conduction abnormalities should suggest a HNPP.