Giant cell fibroblastoma: a variant of dermatofibrosarcoma protruberans treated with Mohs' micrographic surgery

Fibrohistiocytic tumors and related neoplasms in children and adolescents

Fibrohistiocytic tumors (FHTs) in children and adolescents range from the benign fibrous histiocytoma, or dermatofibroma, to a variety of intermediate and malignant neoplasms, such as dermatofibrosarcoma protruberans and high-grade undifferentiated pleomorphic sarcoma (malignant fibrous histiocytoma). Those tumors as a group are comprised of fibroblasts, myofibroblasts, and histiocytes-dendritic cells with a variably prominent inflammatory infiltrate consisting of lymphocytes and eosinophils. Dendritic cells are also a major constituent of another group of neoplasms that include Langerhans cell histiocytosis, follicular and interdigitating cell sarcomas, and juvenile xanthogranuloma. These latter tumors are considered in this discussion for the sake of differential diagnosis and their possible histogenetic relationship to FHTs. Recent studies have suggested that the relationship between the fibroblast and histiocyte in the FHTs may reflect the intrinsic capacity to transdifferentiate from one to the other morphologic and functional state. The so-called "facultative fibroblast," as a cell with fibroblastic and histiocytic properties, was discussed in the context of the fibrous xanthoma 50 years ago. Possibly the entire histogenetic concept of FHTs should be reconsidered in light of current studies.

[Atypical presentation of giant cell fibroblastoma]

BACKGROUND

Giant cell fibroblastoma is a specific entity that belongs to the dermatofibrosarcoma protuberans spectrum. We report an original case with an atypical clinical presentation.

CASE REPORT

A four-year-old male child presented with a perineoscrotal mass, present since the age of one year. This lesion was initially a bluish perineal macule that grew rapidly after a traumatic injury. Physical examination showed a large flaccid bi-lobed tumour originating from the posterior border of the left of the scrotum to the anal margin. A haemolymphangioma was clinically suspected and the results of ultrasound and MRI were consistent with this diagnosis. Because of the discomfort and the atypical clinical presentation, local surgical resection was performed. Histological examination did not confirm the clinical assumption but revealed a giant cell fibroblastoma. Because of the location of this tumour, a secondary surgical procedure was carried out using the "Slow-Mohs" technique.

DISCUSSION

This case is particularly interesting because of the clinical pseudo-angiomatous presentation of this tumour. Use of the "Slow-Mohs" technique allowed sparing of tissue. No recurrence was noted after 3 years of follow-up.

Giant cell fibroblastoma: an update and addition of 86 new cases from the Armed Forces Institute of Pathology, in honor of Dr. Franz M. Enzinger

A quarter of a century ago at the International Academy of Pathology in Boston, Mass, Drs Enzinger and Shmookler's seminal abstract on giant cell fibroblastoma (GCF) included 20 GCFs on the back and thigh of mostly male children. These tumors involved dermis and subcutis, and had parallel fascicles of wavy uniform spindled cells with wiry collagen, dense sclerosis, and gaping spaces with scattered and rimming pleomorphic giant cells. EM suggested fibroblastic phenotype. All cases had benign behavior, but almost half recurred. The caveat was mistaking this tumor for a malignancy. In 1989, Drs Enzinger, Shmookler, and Weiss published this abstract as 28 cases from the AFIP (1960-1981), including 4 adults up to 55 years old. They proposed a relationship of this childhood tumor to dermatofibrosarcoma protuberans (DFSP). Since these original descriptions of GCF, there has been additional immunohistochemical and molecular support for a relationship between DFSP and GCF. We reviewed additional AFIP cases of GCF since 1981, in honor of Dr Enzinger. These new cases included 60 males and 26 females, whose ages ranged from 6 months to 62 years (median, 6 years; 62%, younger than 10 years; 77%, younger than 20 years; and only 10 patients were older than 40 years). Thirty-nine GCF cases with evaluable epidermis were observed to be protuberant, one with superficial ulceration. Most cases were dermal and subcutaneous, 3 purely dermal, and 5 involved superficial skeletal muscle. Almost all cases demonstrated a honeycomb pattern, and several, a parallel pattern of infiltration. Several cases spared adnexa. Pure GCF areas ranged from solid and collagenized to angiectoid and myxoid, the latter with small to large cystlike spaces. Most cases were relatively hypocellular, except one case with more atypia and mitotic activity. GCF demonstrated myoid whorls in 2 cases, a feature previously described in DFSP. Most remarkable is the peculiar perivascular lymphocytes in an onionskin pattern in GCF, not observed in DFSP. Furthermore, histologic intralesional hemorrhage seems to be common in GCF, particularly near the fascia. Fourteen of our 86 cases demonstrated 5% to 70% (median, 20%) dense nongiant cell storiform areas, interpreted as hybrid GCF-DFSP. Three of these cases demonstrated hypercellular DFSP. One hybrid case had fibrosarcomatous transformation. Two cases of pure GCF recurred as a hybrid tumor with DFSP areas, one of these with hypercellular DFSP. In all but one case, the DFSP was adjacent to GCF with an abrupt transition. Most cases studied were positive for CD34 (more intense in DFSP than relatively hypocellular GCF areas) and negative for smooth muscle actin, desmin, HMB-45, keratin, and S100 protein. GCF is exactly clinically and morphologically the same as Dr Enzinger and colleagues originally described it. Additional observations of marked perivascular and onionskin-like chronic inflammation and consistent hemorrhage may aid in the diagnosis of this previously well-described tumor. Collectively, we now have even more convincing morphologic, immunophenotypic, and molecular evidence that GCF is on a spectrum with DFSP.

A very large, rapidly developing, congenital giant cell fibroblastoma in a 5-month old infant

Giant cell fibroblastoma is an uncommon soft tissue neoplasm that occurs in childhood. It seems to be the juvenile form of dermatofibrosarcoma protuberans, which is seen less frequently in children. Only one congenital case has been reported previously. In this report, we present a 5-month-old girl with a rapidly and atypically growing mass located on the upper part of the right scapula. We think that our case is very interesting, because no similarly large lesion (12 cm x 10 cm x 8 cm) related to giant cell fibroblastoma has been previously reported in the published work.

Mohs micrographic surgery of a papillary eccrine adenoma

BACKGROUND

Papillary eccrine adenoma (PEA) is a rare benign sweat gland neoplasm first described by Rulon and Helwig in 1977. Although these lesions typically behave in a benign fashion, PEA's on the volar surfaces may demonstrate more aggressive biologic behavior. Additionally, aggressive digital papillary adenomas (ADPA) may histologically simulate PEAs and behave in a more malignant fashion.

OBJECTIVE

To present a case report of a patient with an incompletely excised PEA that was successfully extirpated using Mohs micrographic surgery (MMS).

METHODS

A 51-year-old black woman was evaluated for the treatment of an incompletely excised PEA located on the dorsum of her left hand at the base of the thumb. Mohs micrographic surgery was felt to be the ideal treatment choice because of incomplete prior resections, ill-defined clinical borders, the need for conservative surgical excision to preserve sensory and motor function of the left hand, and the previously reported more aggressive nature of this tumor when located on volar surfaces. The patient underwent a two-stage, six section micrographically controlled excision using the fresh tissue technique.

RESULTS

Complete resection of the PEA without significant damage to neurovascular structures.

CONCLUSION

This case demonstrates the increasingly important role MMS is playing in the surgical management of a wide variety of cutaneous tumors. To our knowledge, this is the first time MMS has been used in the resection of a PEA.