Cellular neurothekeoma in the arm of a child

Mediastinal neurothekeoma: a rare tumor

Neurothekeoma, also known as nerve sheath myxoma, is a benign nerve sheath tumor that usually arises in the cutaneous nerves of the head, neck, or upper extremities. Extracutaneous placement is very rare. Mediastinal neurothekeoma has not previously been reported in the English literature. A 30-year-old woman was admitted to our clinic with back pain. A smooth-edged mass found in her paravertebral region, and a neurogenic tumor was suspected. The tumor was completely excised. Final pathology revealed it to be a mediastinal neurothekeoma.

Cellular neurothekeoma of the upper lip in an infant

Cellular neurothekeoma is an uncommon benign skin neoplasm and also a variant of neurothekeoma. Cellular neurothekeomas usually occur in the skin of the upper trunk, head, or neck of children and young adults; however, they rarely occur in infants or involve the lip. A 6-month-old male infant was incidentally found to have a tumor in the upper lip. The tumor was elastic, nontender, and movable, and the overlying mucosa and skin were normal without discoloration. The tumor was excised from the mucosal side of the upper lip, and a pathological examination revealed cellular neurothekeoma. Cellular neurothekeoma in the lip of an infant without overlying skin discoloration might delay the diagnosis and lead to wrong preoperative diagnosis. No similar case has been reported in the literature.

Ankle neurothekeoma: a case report

Neurothekeoma is a rare, benign, cutaneous tumor of nerve sheath origin that is also termed benign nerve sheath myxoma. This tumor is usually asymptomatic and grows slowly. Neurothekeoma is typically found in young adults and seldom occurs in children. It is most commonly located in the head, neck, and upper extremity and extremely rarely found in the lower leg. We report a rare case of ankle neurothekeoma in a child, with a review of the related published data.

Giant neurothekeoma in the forearm of an infant

Neurothekeomas are benign tumours of nerve sheath origin. Neurothekeomas present most commonly on the head and neck and upper extremities. These are usually small, slow growing tumours. Most patients with neurothekeoma are young women. We describe a 1-year-old infant with a large and extensive neurothekeoma in the upper extremity. We believe that our patient is one of the youngest cases and the tumour is probably the largest and most extensive neurothekeoma reported in the literature.

An update on plexiform fibrohistiocytic tumor and addition of 66 new cases from the Armed Forces Institute of Pathology, in honor of Franz M. Enzinger, MD

The seminal article of Drs Franz Enzinger and Renyuan Zhang in 1988 defined plexiform fibrohistiocytic tumor (PFHT) as a distinctive entity. They described 65 cases (from 1965 to 1985) in children and young adults, with female and upper extremity predominance. These tumors were morphologically divided into 3 groups: fibroblastic, histiocytic (often with osteoclast-type giant cells), and mixed. Most tumors exhibited a plexiform and infiltrative arrangement of cells at the dermal/subcutaneous junction. Two fibroblastic PFHT had a metaplastic bone formation. Absence of cellular pleomorphism, low mitotic activity, dense hyalinization, hemorrhage, and chronic inflammation were observed. Vascular invasion was present in 1 recurrent, yet nonmetastatic, case. Tumors were negative for S100 protein, desmin, cytokeratin, factor VIIIrag, and lysozyme. Most patients were without disease up to 60 years after excision; 32 (37.5%) cases with follow-up recurred and 2 of those patients had regional lymph node metastasis at 9 and 36 months, respectively, yet there were no systemic metastases. In the interim, there have been additional studies on PFHT. We wanted to update the literature and add 66 new PFHT cases (1986-present) from the Armed Forces Institute of Pathology, since this seminal article, in honor of Dr Franz Enzinger. There were 37 men and 29 women; patient age ranged from 1 to 77 years (median, 20 years; 53% of patients were younger than 20 years). Twenty-eight cases occurred in the upper extremity (mostly forearm), 16 in lower extremity, 11 in trunk, 9 in head and neck, and 2 of unknown site. Although most cases were observed at the dermal/subcutaneous interface, 22 cases were predominantly dermal, and the rest predominantly subcutaneous, with 4 superficially involving skeletal muscle. Except for 12 predominantly dermal cases, most cases had an infiltrative growth pattern. Thirty-four cases were predominantly histiocytic, 16 predominantly fibroblastic, and the remaining 16 mixed. Two fibroblastic cases demonstrated the microfat cells (probably secondary to subcutis infiltration). All cases exhibited a plexiform growth pattern of small- to medium-sized nodules; 41 cases had giant cells, mainly osteoclast type, often the predominantly histiocytic type. The purely fibroblastic often had surrounding inflammation, 2 cases with marked inflammation. Perineural growth was observed in 5 cases, peri-Pacinian corpuscle growth in 2 cases, adnexal trapping in several, and, increased hyalinized collagen in 17 cases. Eight cases demonstrated focal myxoid change. Only 1 case, a histiocytic, had bone formation. Although increased cytologic atypia and mitotic activity were noted in a few cases, an atypical mitosis was only observed in 1 case. No cases demonstrated vascular or lymphatic invasion or necrosis. The tumors were generally positive for CD68 and SMA, occasionally for MSA, and negative for keratin, desmin, HMB45, S100 protein, and CD34. Overall, the findings were very similar to the original observations made by Dr Enzinger and his colleague, with the minor exceptions of roughly equal sex distribution (possibly due to timely referral bias), and additional morphologic features of myxoid change, adnexal sparing, increased inflammation, and microfat similar to recently described lipofibromatosis. The relationship between PFHT and cellular neurothekeoma is also explored.

Atypical cellular neurothekeoma treated with Mohs micrographic surgery

BACKGROUND

Atypical cellular neurothekeoma is a rare neoplasm generally regarded as a benign tumor with locally aggressive behavior. Recurrence is common with inadequate excision, but metastatic disease has yet to be reported.

OBJECTIVE

The objective was to report a case of atypical cellular neurothekeoma of the nasal ala in a young woman treated by Mohs micrographic surgery. The biologic behavior and histopathology will be reviewed.

METHODS

Case report and review of the literature.

RESULTS

The neoplasm was extirpated in a three-stage, five section Mohs surgery procedure. The resulting defect was repaired by a two-stage, pedicled nasolabial transposition flap with a cartilage graft taken from the ipsilateral ear. No clinical recurrence was noted after 6-months of follow-up.

CONCLUSION

Mohs micrographic surgery is unsurpassed in its efficacy in treating a wide variety of nonmelanoma skin cancers. Although most commonly used to address basal and squamous cell carcinoma, it has also been reported as a successful treatment for melanoma and a wide variety of cutaneous malignancies. We discuss a case of atypical cellular neurothekeoma removed with the Mohs technique. Debate in the literature is ongoing regarding the true histogenesis of this rare tumor. Because of this tumor's local destructive behavior and propensity to recur with inadequate resection, we recommend Moths micrographic surgery for the treatment of cellular neurothekeomas.