RESUMEN

Malignant primary lymphoma of the thyroid gland is a rare disease. The principal clinical sign is a rapidly growing goiter, leading to signs of compression, raising the question of differential diagnosis with anaplastic cancer. Multimodality therapy with surgery, radiotherapy, and chemotherapy appears to be of value. We retrospectively reviewed the management and outcomes of five consecutives patients with thyroid lymphoma.

Asunto(s)

RESUMEN

AIMS: Lipoblastoma is a rare benign adipocytic neoplasm that occurs primarily in infancy and early childhood. Histologically, there is some morphological overlap with atypical lipomatous tumour and myxoid liposarcoma and the age at presentation is often regarded as a major diagnostic criterion. However, we recently encountered several cases of lipoblastoma occurring in adolescents and young adults. The aim was to document the occurrence of lipoblastoma in older patients, with cytogenetic confirmation. METHODS AND RESULTS: Six cases of lipoblastoma in patients >12 years old were identified. The tumours occurred in four male and two female patients ranging from 14 to 24 years old. Our cases showed the classical histological features of lipoblastoma. Three tumours were composed predominantly of mature adipocytes and the three other cases showed an immature appearance, with a prominent myxoid matrix. Fluorescence in situ hybridization (FISH) demonstrated rearrangements of the PLAG1 region in two cases and polysomy for chromosome 8 in three other cases. None of the tumours had amplification of MDM2 or CDK4. CONCLUSIONS: Lipoblastoma occurs rarely in young adults and should enter into the differential diagnosis of 'atypical' fatty tumours in adults. Our report underscores the diagnostic value of FISH analysis.

Asunto(s)

RESUMEN

The so-called perivascular epithelioid cell neoplasm (PEComa) family includes angiomyolipoma, clear cell 'sugar' tumor (CCST), lymphangioleiomyomatosis, and clear cell myomelanocytic tumor (CCMMT). These rare tumors are characterized by the co-expression of melanocytic and muscle markers. They have been recognized in an increasing number of sites but currently only one case of PEComa, of the CCMMT subtype, has been reported in the skin in abstract form. We provide the clinicopathologic description of a case of extrapulmonary CCST located in the dermis and superficial subcutis of the thigh of a 60-year-old female. The lesion was composed of nests of epithelioid and spindle cells with abundant clear to granular cytoplasm and distinct cell borders. The tumor showed strong and diffuse immunoreactivity with HMB-45. Scattered cells expressed desmin and h-caldesmon. Antibodies to S-100 protein, melan-A, cytokeratins, and smooth muscle actin were negative. This first case of cutaneous PEComa of the CCST type expands the differential diagnosis of clear cell/granular cell tumors of the skin.

Asunto(s)

Asunto(s)

RESUMEN

Dermatofibrosarcoma protuberans is a rare mesenchimal tumour mainly characterized by its local aggressiveness and high reported recurrence rates. Classically, wide excisional surgery with at least 3 cm of free tissue margins is recommended as treatment. We present a series of 18 patients with variable gross free tissue margins but confirmed histological free margins in all cases whatever the surgical excision really was. Only one patient presented a local recurrence (5.5%) of a very large (14 cm) sarcomatous variant of dermatofibrosarcoma protuberans. Mean follow-up in this series was 52.1 months. Those results emphasize that histological rather than theoretical "golden rules" are mandatory to locally control this aggressive neoplasm.

Asunto(s)

RESUMEN

We present a series of 4 cases of fibrosarcomatous dermatofibrosarcoma protuberans. This variant, which is composed of areas of typical DFSP associated with more cellular, fascicular foci, reminiscent of fibrosarcoma, should be recognised because of its more aggressive behavior, with a significant metastatic potential (15%). Our series illustrates the clinical, morphological, immunohistochemical and cytogenetic features of this uncommon tumor, with emphasis on differential diagnosis.

Asunto(s)

RESUMEN

Synovial sarcoma (SS) is a relatively rare sarcoma, which may be confused with several other mesenchymal and nonmesenchymal lesions. It bears the t(X;18) (SYT;SSX) translocation, which seems to be specific for this tumor type and can be detected in paraffin-embedded tissue, using reverse transcriptase-polymerase chain reaction (RT-PCR). However, the specificity and sensitivity of this detection method have rarely been examined in a large series. Using RT-PCR, we examined 250 mesenchymal and nonmesenchymal, benign and malignant, paraffin-embedded lesions for the SS t(X;18) (SYT-SSX) translocation. PCR products were obtained from 221 tumors (88.5%). There were 135 non-SS tumors, 22 biphasic, and 64 monophasic spindle/round cell SS, of which 10 were cytogenetically confirmed as t(X;18)-positive. SYT-SSX gene fusion transcripts were detected in the SS tumor category only (100% specificity), including 100% of the biphasic SS and 86% of monophasic spindle/round cell SS. Nine tumors originally diagnosed as SS were t(X;18) (SYT-SSX)-negative. Following reassessment, only 3 of these tumors showed clinicopathologic, immunohistochemical, and/or ultrastructural features consistent with that diagnosis, thus raising the overall detection sensitivity to 96%. With regard to the potential adverse effect of the fixatives used, PCR products were obtained in 100%, 91.5%, 90.5%, and 0% of tumors fixed with AFA, buffered formalin, Holland Bouin, and conventional Bouin's fluid, respectively. This study shows that the detection of the SS t(X;18) (SYT-SSX) in paraffin-embedded tissue is feasible with a 100% specificity and an overall 96% sensitivity, provided non-Bouin's fluid fixation is used.

Asunto(s)

RESUMEN

Leiomyosarcoma in the pediatric age group is uncommon and incompletely characterized. A series of 20 primary leiomyosarcomas of soft tissue occurring in children younger than 16 years is presented. No significant gender predilection was observed (11 girls and 9 boys). Patient age ranged from 4 to 15 years (median, 12 years). Tumor size ranged from 0.5 to 13 cm (median, 2.5 cm); subcutaneous and deep locations were equally represented. Tumors were evenly distributed among the trunk (30%), head and neck (25%), lower limbs (25%), and upper limbs (20%). All lesions showed at least focally typical features of smooth muscle differentiation, principally in the form of fascicles of eosinophilic spindle cells with cigar-shaped nuclei. An unusual whorled growth pattern was seen in two cases. Morphologic variants including inflammatory leiomyosarcoma (one case), granular cell leiomyosarcoma (two cases), giant-cell rich leiomyosarcoma (two cases), and epithelioid leiomyosarcoma (one case) were seen. Dystrophic calcifications were present in two cases. Most lesions (85%) were low grade. Immunohistochemical staining showed positivity for alpha-smooth muscle actin in 89% of the cases, HHF-35 in 87%, and desmin in 61%. Positivity for cytokeratins, observed in 6 (43%) of 14 cases tested, was usually strong and was diffuse in two cases. Follow-up data, available in 15 (75%) patients (median duration, 49 months), showed late local recurrence in only two cases, one with progression to a higher grade lesion, and no metastasis. These results show that, although extremely rare, soft-tissue leiomyosarcomas do occur in children, in whom they usually present as small morphologically low-grade lesions that seem to behave in a relatively indolent fashion, although longer follow-up data are needed. Differential diagnosis in this setting includes infantile myofibromatosis, leiomyoma, monophasic synovial sarcoma, and spindle cell rhabdomyosarcoma.

Asunto(s)

RESUMEN

Focal myxoid change is a well-recognized feature of solitary fibrous tumor (SFT), but to date, predominantly myxoid examples of SFT have not been reported. We describe seven cases of SFT in which stromal myxoid change affected 50% or more of the tumor examined, thus obscuring typical diagnostic features. Patients ranged in age from 35 to 68 years old (median, 45 yr), with an equal sex distribution. Tumor locations included pleura, orbit, and periparotid subcutaneous tissue, as well as four cases in deep soft tissue (two in the abdominal wall and one each in the chest wall and thigh). Myxoid areas were identified grossly in four cases. Histologically, the lesions were composed of bland spindle cells disposed haphazardly or with a lacy or reticulated appearance in a myxoid, richly vascularized stroma These myxoid areas were punctuated by small cellular aggregates in four cases, and areas showing diagnostic features of SFT were present in five of seven primary excision specimens. Atypical features suggestive of malignancy were not present in any of the cases. Immunohistochemically, all of the seven cases stained positively for CD34 and CD99 (013), and all were negative for smooth muscle actin, desmin, S-100 protein, epithelial membrane antigen, and pan-keratin. There were no recurrences or metastases reported in four patients with limited follow-up (median duration, 19 mo). Recognition of this uncommon morphologic subset of SFT is important because of possible confusion, particularly in small biopsy specimens, with a variety of myxoid spindle cell neoplasms with different biologic potential. These include low-grade fibromyxoid sarcoma, myxoid synovial sarcoma, malignant peripheral nerve sheath tumor, low-grade myxofibrosarcoma, myxoid liposarcoma, myxoid spindle cell lipoma, myxoid neurofibroma, and so-called "hemangiopericytoma."

Asunto(s)

RESUMEN

Dendritic cells (DC) are the most potent antigen-presenting cells, and induce antigen-specific immune responses. Infiltration of tumors by DC is thought to reflect the interaction between the host immune system and tumor cells. Tumor-infiltrating DC (TIDC) are believed to evolve into tumor-antigen pulsed cells and then to migrate to local lymph nodes, where they activate anti-tumor immune responses. Indirect clinical evidence supporting this theory is provided by studies showing that high TIDC densities are associated with favorable prognosis in some tumor types. In the present study, we evaluated 143 primary breast adenocarcinomas for the presence of DC, using immunohistochemistry with the anti-S100 protein antibody. We analyzed the relationship between the degree of infiltration by S100+ TIDC and the usual prognostic factors and clinical outcome. The results show that 42% of breast adenocarcinomas contain S100 TIDC. The number of S100+ TIDC varies according to the grade of tumors as follows: GRIII > GRII > GRI. A relationship is also found between S100+ TIDC and tumor size, lymph-node involvement, estrogen/progesterone receptor status and age. However, the presence of S100+ TIDC, even at the highest density, was not correlated with metastasis-free survival or overall survival.

Asunto(s)

RESUMEN

Despite their relative infrequency (which is often used as an excuse for poor treatment), soft-tissue sarcomas have been the focus of considerable interest and advances in recent years, mainly because of molecular genetic developments as well as evolution in their histological classification. In parallel, however, there remains no clear consensus regarding either the ideal biopsy technique (in this era of increasing outpatient management) or the best means of prognostication (particularly by histological grading). This review aims to discuss some of these recent developments and co-existent controversies. Aside from the understandable pursuit of modern biotechnological innovations, it seems that the most important goal remains the need to achieve more consistent primary surgical management of these tumours, preferably in specialist centres.

Asunto(s)

RESUMEN

Pseudoangiomatous hyperplasia of the mammary stroma is a benign mesenchymal proliferative lesion. It is rarely observed as a tumor mass that has to be differentiated from angiosarcoma. We give a review of the literature and report a case unusual in that it occurred in a clinical setting of HIV infection, was rapidly growing, and has been the largest described so far.

Asunto(s)

RESUMEN

Necrotizing Sialometaplasia is an inflammatory, self-healing, reactive process of probable vascular origin, that most commonly involves the minor salivary glands of the palate but can bee seen in all salivary glands. As its clinical and pathological features may suggest malignancy, knowledge of histologic criteria indicating the benign nature of the lesion and the integration of clinical and pathologic elements are required to obviate this mistake. We review the literature reporting to one case.

Asunto(s)