Inflammatory myofibroblastic tumor of the skin

Superficial CD34-positive fibroblastic tumour: a clinicopathological and immunohistochemical study of an additional series

AIMS

To describe an additional series of superficial CD34-positive fibroblastic tumour, a newly described neoplasm, in order to enhance the recognition of an emerging novel entity.

METHODS AND RESULTS

The clinicopathological features and immunophenotypes of 11 cases of superficial CD34-positive fibroblastic tumour were studied. There were eight males and three females, with a median age of 36 years. Tumours occurred in the thigh (n = 4), buttock (n = 3), shoulder (n = 2), upper arm (n = 1), and waist (n = 1). Histologically, all tumours were characterized by relative circumscription, pleomorphic spindled to polygonal cells with variably enlarged bizarre-appearing cells, intranuclear cytoplasmic pseudoinclusions, and extremely low mitotic activity. Immunohistochemically, neoplastic cells showed diffuse and strong expression of CD34 and focal staining of cytokeratin. Follow-up thus far has revealed an indolent clinical behaviour.

CONCLUSIONS

Superficial CD34-positive fibroblastic tumour represents a new member of the family of cutaneous CD34-positive spindle-cell tumours. Familiarity with its clinicopathological characteristics is helpful in avoiding confusion with a variety of cutaneous mesenchymal tumours with overlapping features.

Atypical fibrous histiocytoma of the skin with CD30 and p80/ALK1 positivity and ALK gene rearrangement

We report the case of a two patients who presented with a solitary, asymptomatic, angiomatoid nodule on the right thigh. Histopathological finding showed a poorly circumscribed lesion, located in the dermis. The morphological aspect strongly suggested the diagnosis of atypical fibrous histiocytoma (AFH), but surprisingly, the neoplastic cells were diffusely CD30+, with a membrane staining devoid of paranuclear dot. The lesions were tested for p80/ALK1 expression. Surprisingly, we found a diffuse cytoplasmic positivity. Interestingly, using break-apart fluorescent in situ hybridization (FISH), we evidenced an ALK rearrangement in nearly 50% of the neoplastic cells. The expression of CD30 and ALK1 with ALK gene rearrangement raised the possibility of three diagnoses: a primary cutaneous anaplastic large cell lymphoma (ALCL), a cutaneous inflammatory myofibroblastic tumor (IMT), an AFH of the skin associated with ALK gene rearrangement and CD30 positivity. The three hypotheses were discussed and finally, although p80/ALK1 expression and cytogenetic abnormalities in fibrous histiocytoma (FH) are not yet reported to the best of our knowledge, we favored the diagnosis of AFH.

A case of cutaneous inflammatory myofibroblastic tumor

Pseudo-inflammatory tumors are also known as plasma cell granuloma, inflammatory pseudo-tumor and inflammatory myofibroblastic tumor, and these tumors are a group of highly variable proliferations of myofibroblastic cells that are associated with a prominent inflammatory infiltrate. This tumor is known to most commonly occur in the lungs, bladder and gastrointestinal system with only a few cases having been reported in the skin. A previously healthy 26-year-old man presented with a 6-year history of an intermittently pruritic lesion on his back. On the histologic examination, there were spindle cells in fascicles and a mixed inflammatory cellular infiltrate of plasma cells and lymphocytes. A diagnosis of inflammatory fibroblastic tumor was made and the nodule was surgically removed. We report here on an additional case of this rare cutaneous entity, and it is probably the first such report from Korea.

A unique case of multiple dermatomyofibromas

We report on a case of multiple dermatomyofibromas on the posterior neck of a 10-year-old boy. Dermatomyofibroma is a benign proliferation of myofibroblasts of the skin. It is more common in adolescents and young adults, with a female preponderance. It usually appears as a single plaque or nodule. To our knowledge, this is the first case of multiple dermatomyofibromas reported in the literature.

So-called inflammatory myofibroblastic tumour: a proliferative lesion of fibroblastic reticulum cells?

The term inflammatory pseudotumour was originally used in a generic fashion for any lesion which simulated a neoplastic condition at a clinical, macroscopic and microscopic level but which was thought to have an inflammatory/reactive pathogenesis. In more recent times, the term has been employed in a more restrictive sense for a mass lesion characterized microscopically by the proliferation of a spindle cell component against a heavy inflammatory infiltrate of mixed composition but usually with a predominance of mature lymphocyte and plasma cells. The spindle cell component has generally been regarded as being of mesenchymal nature and having morphological and phenotypical features consistent with fibroblasts or myofibroblasts, the latter cell being clearly preferred over the former in the more resent reports. The term inflammatory myofibroblastic tumour (IMFT) is the one currently favoured, which proposes the myofibroblastic nature of the process. It is the purpose of this review to bring forth some evidence that the neoplastic spindle cell component of IMFT may be instead derived from the subtype of cells of the accessory immune system that have been variously called fibroblastic reticulum cells, myoid cells, and dictyocytes.

A case of isolated cutaneous pseudo-inflammatory tumour

Pseudo-inflammatory tumours are a poorly defined group of tumours, with indeterminate malignant potential, which can occur at almost any site of the body. The optimal treatment of inflammatory pseudo-tumours is yet to be elucidated. Surgical excision has been the most frequently reported treatment in the literature. We report a case of solitary cutaneous inflammatory pseudo-tumour.

Cutaneous inflammatory pseudotumor - a spectrum of various diseases?

BACKGROUND

Inflammatory pseudotumor (IPT) also known as inflammatory myofibroblastic tumor (IMT) or plasma cell granuloma (PCG) has been rarely reported in the skin.

METHODS

We describe five patients with cutaneous IPT and present clinicopathologic features along with detailed immunohistochemical analysis including anaplastic lymphoma kinase (ALK)-1.

RESULTS

The patients age ranged from 15 to 89 years with a median of 56 years. All patients presented with solitary, firm, papules and nodules. There was no evidence of constitutional symptoms, local recurrence, or lymph node involvement. Histopathological examination revealed two distinct patterns; one type (n = 3) displayed dense, lymphoplasmacytoid infiltrates containing lymphoplasmacytoid cells and plasma cells with occasional germinal centers and hyalinized collagen bundles but was devoid of a myofibroblastic component. It showed features of tumors previously described as cutaneous PCG. Although an infectious etiology, including Borrelia burgdorferi-specific DNA, could not be demonstrated, we observed many features that overlapped with those of fibrous nodules of acrodermatitis chronica atrophicans. The other pattern (n = 2) revealed spindled myofibroblasts focally arranged in a fascicular pattern, an admixed lymphoplasmacytoid infiltrate set in a background of thickened collagen bundles, findings akin to the conventional type of IMT. The cases with a myofibroblastic component (n = 2) did not show any evidence of ALK-1 reactivity.

CONCLUSIONS

We believe that the term cutaneous IPT subsumes lesions of diverse etiology. Tumors with detectable myofibroblasts represent true cases of IMT. Cutaneous PCG is a discrete disorder biologically distinct from conventional IMT representing a reaction pattern that is also found in disorders, such as spirochete-induced fibroid nodules and localized chronic fibrosing vasculitis.

Monophasic sarcomatoid carcinoma of the scalp: a case mimicking inflammatory myofibroblastic tumor and a review of cutaneous spindle cell tumors with myofibroblastic differentiation

BACKGROUND

The evaluation of malignant cutaneous spindle cell tumors is challenged by a diagnostic differential that comprises neoplasms of diverse histogenesis, and a broad immunohistochemical panel may confound the diagnosis when the results suggest multiple lines of differentiation, such as with a combined myofibroblastic and epithelial phenotype.

METHODS

We report the case of a solitary scalp nodule that quickly became locally metastatic. A comprehensive panel of immunohistochemistry markers and electron microscopy was evaluated to determine the differentiation of the spindle cells.

RESULTS

The tumor, consisting of wavy and slender spindle cells with predominantly bland nuclei, showed immunoreactivity to vimentin, smooth muscle actin, and muscle-specific actin. AE1/AE3, CK5/6, and MNF-116 antibodies were weakly positive in rare cells. However, 34betaE12 showed diffuse positivity in the spindle cell population, thus supporting the diagnosis of a sarcomatoid carcinoma with myofibroblastic differentiation.

CONCLUSIONS

The use of 34betaE12 is essential for the evaluation of myofibroblastic spindle cell tumors with rare cytokeratin reactivity. However, even with immunohistochemical and electron microscopic studies, the diagnosis of spindle cell tumors can be confounded by the multiplicity of nosologic equivalents, such as carcinosarcoma, spindle cell carcinoma, and metaplastic carcinoma. The nomenclature of these spindle cell tumors is discussed.

Renal pseudotumor simulating malignancy in a patient with Adamantiades-Behçet's disease: case report and review of the literature

Adamantiades-Behçet's disease is a multisystem recurrent syndrome with vasculitis being the underlying histopathological lesion. We report on a patient with Behçet's disease who developed a renal mass raising the suspicion of a malignant neoplasm. The pathologic examination revealed an inflammatory pseudotumor. The concurrent presentation of these two entities seems to be more than coincidental.