Sorafenib for relapsed FLT3-ITD-positive acute myeloid leukemia postallogeneic stem cell transplantation presenting as leukemia cutis.

Relapse of FLT3-mutated acute myeloid leukemia (AML) following allogeneic stem cell transplantation is associated with poor survival. The clinical utility of sorafenib monotherapy in this setting is described in a patient presenting as leukemia cutis.

Primary cutaneous adenoid cystic carcinoma: a clinicopathologic and immunohistochemical study of 27 cases.

AIMS: This study examines clinical and pathologic features of primary cutaneous adenoid cystic carcinoma (ACC), with emphasis on biological behavior of these tumors. A total of 27 cases of primary cutaneous ACC with detailed follow-up information were evaluated. Clinically, these were solitary, slow-growing lesions, half of which were in the head and neck area. The median age was 62 years with a male predilection. Surgical excision was the treatment of choice. Histologically, the lesions were similar to those seen in the salivary glands. Tumors were classified as grade 1 (17), grade 2 (3), and grade 3 (7). The mitotic count was generally low (mean=1.9/mm), except in 2 high-grade tumors (>10 mitotic figures/mm). Sixteen cases showed perineural invasion. Immunohistochemically, cytokeratin positivity was noted in 13/13 cases, and CD117 was observed in 10/10 cases, with luminal/cytoplasmic staining for epithelial membrane antigen (14/16) and at least focal luminal expression for carcinoembryonic antigen (11/16), smooth muscle actin (10/13), and S100 staining (9/13). Eighteen cases had follow-up data (median 54 mo), 9 of which had local recurrences (50%). Three cases showed metastatic disease. No statistical difference was noted between tumor grade and local recurrence (P=0.77). Primary cutaneous ACC is a distinct entity with a more indolent behavior compared with its salivary counterpart. The cutaneous lesions tend to recur locally but have a low metastatic potential.

Crystal deposition in a case of cutaneous Rosai-Dorfman disease.

Rosai-Dorfman Disease (RDD) is an idiopathic reactive proliferation of distinctive histiocytes that have abundant cytoplasm and commonly exhibit intracytoplasmic ingestion of inflammatory cells (emperipolesis). The histiocytes are immunopositive for S100 protein and are typically associated with an infiltrate of lymphocytes, plasma cells, and neutrophils. The classic clinical presentation is massive enlargement of (usually) cervical lymph nodes with a histologic appearance that mimics exaggerated sinus histiocytosis. RDD can also involve extra-nodal sites and skin involvement is common either as part of disseminated disease or as a result of primary disease. We report an exceptional case of cutaneous RDD with crystal deposition in a young male presenting with skin nodules. Skin biopsy showed classic features of cutaneous RDD with the additional feature of conspicuous rhomboidal and needle-shaped crystals within the cytoplasm of many lesional plasma cells, histiocytes, and also in an extra-cellular location. The plasma cells were polyclonal by light chain immunostaining. Crystal deposition has not been reported to date in RDD and is likely a result of the reactive plasma cell proliferation.

Pleomorphic liposarcoma: clinicopathologic analysis of 57 cases.

Pleomorphic liposarcoma is an uncommon form of liposarcoma that only recently has been properly characterized. A series of 57 cases is presented. Patient age at presentation ranged from 27 to 95 years (median, 54 years), and there was a slight male predilection (male/female ratio = 1.2:1). Tumors most frequently involved the lower limb (47% of cases) or upper limb (18%). Other anatomic sites, including trunk (14%), retroperitoneum (7%), head and neck (5%), abdomen/pelvis (5%), and spermatic cord (4%), were less frequently involved. Tumor size ranged from 1.5 to 21 cm (median, 8 cm), with deep (subfascial) locations (39 cases) being more frequent than subcutaneous (11 cases) or dermal sites (5 cases). All lesions showed features of pleomorphic sarcoma and at least focally contained typical multivacuolated lipoblasts. Although there was considerable overlap, tumors fell into three broad categories: high-grade pleomorphic/spindle cell sarcoma with scattered lipoblasts or sheets of lipoblasts (60%), high-grade pleomorphic sarcoma with epithelioid areas and scattered lipoblasts (28%), and intermediate- to high-grade sarcoma predominantly resembling myxofibrosarcoma except for the presence of lipoblasts (12%). Immunohistochemistry revealed focal staining for smooth muscle actin in 13 of 29 cases (45%), S-100 protein positivity in lipoblasts in 15 of 45 cases (33%), focal staining for keratin in 6 of 28 cases (21%), including 5 of 13 (38%) with epithelioid morphology, and focal staining for desmin in 4 of 30 cases (13%). Follow-up data, available in 50 patients (88%) (median, 33 months), showed local recurrence in 34% of patients, systemic metastases in 32%, and tumor-related death in 32%. Only 2 of the 16 superficial (dermal or subcutaneous) lesions metastasized. Five-year overall, local recurrence-free, metastasis-free, and disease-free survivals were 63%, 58%, 58%, and 39%, respectively. By univariate analysis, central (nonextremity) location, deep situation, tumor size > or =10 cm, mitotic rate > or =10 per 10 HPF, necrosis, and epithelioid morphology were associated with a worse prognosis. However, by multivariate analysis, only age > or =60 years, central location, tumor size, and mitotic rate remained independent predictors for an adverse outcome. By multivariate analysis, wide local excision or amputation and postoperative radiotherapy protected against local recurrence.

Intravascular myopericytoma.

BACKGROUND: Myopericytoma is a benign tumor composed of cells that show apparent differentiation towards putative perivascular myoid cells called myopericytes. It arises most commonly in the dermis or subcutaneous tissue of the extremities in adults. METHODS: We describe a myopericytoma that was unusual in its intravascular location. RESULTS: A 54-year-old man presented with a 10-year history of a painful slowly growing 1.5-cm nodule in the subcutaneous tissue of the thigh. Histologic examination of the excised lesion showed that is was entirely contained within the lumen of a vein. It was composed of a proliferation of myoid-appearing spindle cells, which were arranged in a striking concentric pattern around numerous blood vessels, in a manner that accentuated the vessel walls. This pattern is characteristic of myopericytoma. In some areas, fascicles of spindle cells, embedded in a myxoid stroma, bulged into the lumina of lesional vessels, reminiscent of myofibroma/myofibromatosis. Lesional spindle cells were diffusely positive for smooth muscle actin, focally positive for CD34 and were negative for desmin, cytokeratin, S100 protein, HMB-45 and CD31. CONCLUSION: This case illustrates that myopericytoma can be entirely intravascular in its location.

Reactive angioendotheliomatosis: a study of 15 cases demonstrating a wide clinicopathologic spectrum.

Reactive angioendotheliomatosis (RAE) is a rare condition characterized by cutaneous vascular proliferation that usually occurs in patients with diverse types of coexistent systemic disease. Although intravascular proliferation of endothelial cells has been considered to be the key histologic feature in RAE, other patterns of vascular proliferation have also been described. We reviewed the clinicopathologic features in 15 cases of RAE. The study group comprised eight males and seven females with an age range of 47-88 years (median 65 years). Eleven patients had coexistent systemic disease: renal disease (six patients, including three post renal transplantation); valvular cardiac disease (two patients); one patient each had alcoholic cirrhosis, glioblastoma multiforme (on chemotherapy), and rheumatoid arthritis/polymyalgia rheumatica. Six patients were iatrogenically immunosuppressed at the onset of the skin lesions. The clinical appearance included multiple erythematous macules, plaques, tumors, and ulcerated lesions, with a wide distribution but a propensity to involve limbs. Lesions had been present for 1 month to 4 years (median 4 months). Lesions resolved in four cases, improved in two cases, remained static in one case, and progressed in four cases. Two cases were recent and follow-up was not available in two other cases. Three patients died of their coexistent systemic disease with resolution, improvement, and progression of lesions, respectively. All lesions were characterized histologically by a proliferation of capillaries in the dermis, with variably diffuse (seven cases), lobular (six cases), or mixed lobular and diffuse patterns (two cases). There was marked intercase and intracase heterogeneity in histologic features. Common features included fibrin microthrombi (nine cases), reactive (fasciitis-like) dermal alterations (seven cases), and foci of epithelioid endothelium (four cases). Four of 10 cases tested showed positive immunohistochemical staining for HHV-8 latent nuclear antigen in lesional endothelial cell nuclei. This study suggests that RAE has a broader clinicopathologic spectrum than previously described. The pathogenesis of this rare disorder is unknown, but it is likely that immunologic factors play a role.

Liposarcomas/atypical lipomatous tumors of the oral cavity: a clinicopathologic study of 23 cases.

Liposarcomas in the oral cavity have rarely been described, with less than 50 reported cases to date and a purported predominance of the myxoid type. We reviewed our experience with 23 atypical lipomatous tumors/liposarcomas of the oral cavity. Twelve patients were men, 10 were women, and gender was not stated in one case. Age at presentation ranged from 28 to 83 years (median, 49.5 years). The most commonly affected site was the tongue and most cases presented as a slowly growing, painless mass. The clinical impression was lipoma or fibroma in the majority of cases. Tumor size ranged from 0.6 to 8.0 cm (median, 1.5 cm). Five cases were well circumscribed, 5 cases were focally infiltrative, and 13 cases had markedly infiltrative margins. Twenty-one cases were classified as atypical lipomatous tumors (of which 10 showed spindle cell features), one as dedifferentiated liposarcoma, and one as myxoid liposarcoma. Follow-up data was available in 13 of the 23 cases. Five others were lost to follow-up after a short period. Eleven patients remained free of disease without local recurrence or metastasis during the period of follow-up that ranged from 10 months to 9 years (median, 24 months). Two patients had multiple local recurrences. Our study shows that atypical lipomatous tumor is the most common type of malignant fatty tumor to arise in the oral cavity with an apparently low risk of recurrence if widely excised, although follow-up is relatively limited thus far.

Atypical fibrous histiocytoma of the skin: clinicopathologic analysis of 59 cases with evidence of infrequent metastasis.

Atypical fibrous histiocytoma is an uncommon, poorly documented variant of cutaneous fibrous histiocytoma. We studied 59 cases of atypical fibrous histiocytoma to better characterize the clinicopathologic spectrum. There were 33 males and 26 females (median age 38 years; range 5-79 years) with solitary lesions arising on lower (25 cases) and upper (17 cases) extremities, trunk (6 cases), head and neck (4 cases), and vulva (1 case); anatomic location was not stated in six cases. Lesions measured 0.4-8 cm in diameter (median 1.5 cm) and clinically were nodules (40 cases), polypoid tumors (18 cases), or a slightly elevated plaque (1 case). Histologically, the lesions were primarily dermal with superficial involvement of the subcutis in one third of the cases. Salient features included a proliferation of pleomorphic, plump, spindle, and/or polyhedral cells with mainly large, hyperchromatic, irregular, or bizarre nuclei, set in a background of classic features of fibrous histiocytoma, including spindle cell areas showing a storiform pattern and entrapped thickened, hyaline collagen bundles, especially at the periphery. Multinucleated giant cells, often with bizarre nuclei and foamy, sometimes hemosiderin-rich, cytoplasm were also variably present. The degree of pleomorphism varied from only focal and minimal (14 cases) or moderate (24 cases) to marked (21 cases). Mitotic activity was observed in 55 lesions, and the number of mitotic figures ranged from 1 to 15 per 10 high power fields. Atypical mitoses were noted in 20 lesions. Furthermore, some cases of atypical fibrous histiocytoma displayed other worrisome features less often observed in ordinary FH, including unusually large size (diameter >2 cm, 8 cases), involvement of the superficial subcutis (19 cases), and geographic necrosis (7 cases). Immunohistochemical studies performed in 42 cases showed only focal smooth muscle actin (10 cases) and CD34 (4 cases) positivity, whereas CD68, S-100 protein, desmin, pan-keratin, and epithelial membrane antigen were negative. Clinical follow-up data available in 21 patients (mean duration of follow-up 50.6 months, median 43 months) revealed local recurrences in three patients (one repeated); two patients developed distant metastases, one of whom died after 96 months. These two cases were not histologically distinct from the group as a whole. We conclude that atypical fibrous histiocytoma has a broader clinicopathologic spectrum than previously realized. Lesions with floridly atypical features represent potential pitfalls for overinterpretation as pleomorphic sarcoma, which would appear to be inappropriate in most cases. Provided that atypical fibrous histiocytoma is treated by complete excision, a benign outcome is to be expected in most cases. However, similar to the cellular and aneurysmal variants of fibrous histiocytoma, atypical fibrous histiocytoma shows a higher tendency to recur locally than ordinary fibrous histiocytoma and may rarely metastasize.

Fibrous Lesions of the Breast: A Review.

Fibrous lesions of the breast are challenging for a number of reasons. They occur infrequently and there is significant clinical, radiologic, and histologic overlap between reactive and neoplastic lesions, as well as with some nonfibrous lesions. Pure fibrous lesions of the breast encompass reactive conditions, such as scars and nodular fasciitis, and neoplastic entities, such as the distinct benign mammary myofibroblastoma, locally aggressive fibromatosis, and rare true sarcomas. In this review, we focus on nodular fasciitis, mammary myofibroblastoma, and primary mammary fibromatosis. We also briefly discuss spindle cell metaplastic carcinoma because it represents the most important differential diagnosis through its ability to closely simulate nodular fasciitis and fibromatosis. Caution should be exercised in the interpretation of fibrous lesions of the breast, especially if the tissue sample is limited. Int J Surg Pathol 8(2):99-108, 2000