Donald R. Chase

Epithelioid sarcoma: diagnosis, prognostic indicators, and treatment

A retrospective review of 241 cases of epithelioid sarcoma reaffirmed the propensity of this tumor to occur in the distal extremities of young adults. The tumor was generally firm and nontender, and involved the dermis, subcutis or deeper soft tissues, particularly fascial planes, aponeuroses, and tendon sheaths. Follow-up data, available in 202 cases (84%), showed a 77% recurrence and a 45% metastatic rate. The most common initial sites of metastasis were lymph nodes (48%) and lungs (25%). A more aggressive course was associated with a proximal or axial tumor location, increased size and depth, hemorrhage, mitotic figures, necrosis, or the presence of vascular invasion. More favorable behavior was observed when the tumor arose in younger individuals, in distal extremities, or in females between the ages of 10 and 49. (The last observation calls for further work with steroid receptors.) Radical excision or amputation still appears to be the initial treatment of choice, though adjunctive high-dose radiotherapy to the excision site may prove to be of additional value.

Keratin in epithelioid sarcoma. An immunohistochemical study.

Intermediate-sized filaments have been noted in epithelioid sarcoma by previous investigators, two of whom have reported that the filaments represent vimentin. We utilized polyclonal antibodies directed against keratin and immunoperoxidase techniques (PAP) to stain 32 of the more than 300 cases accumulated at the AFIP. All of our material was formalin-fixed, paraffin-embedded. Seventy-five percent of our cases (24/32) showed positive immunoreactivity, a feature that may be of diagnostic help in distinguishing epithelioid sarcoma from nodular fasciitis, benign and malignant fibrous histiocytoma, malignant melanoma, and necrotizing granuloma. In these cases, the reaction was enhanced using predigestion with trypsin. The immunoreactivity varied from tumor or tumor, perhaps due to formalin fixation. Since synovial sarcoma and mesothelioma may also be cytokeratin-positive, our findings indicate that keratin immunoreactivity is not confined to epithelial tumors and may also occur in neoplasms traditionally regarded as mesenchymal.

Adrenal myelolipomas show nonrandom X-chromosome inactivation in hematopoietic elements and fat: support for a clonal origin of myelolipomas.

Myelolipomas are defined as mature fat associated with hematopoietic elements, often found in the adrenal gland. The question of whether the hematopoietic cells are truly “normal” has not been evaluated extensively. In this study, we evaluated histologic, immunohistochemical features and comparisons of X-chromosome inactivation patterns in 19 myelolipomas. Formalin-fixed, paraffin-embedded tissue from 19 myelolipomas was stained with hematoxylin and eosin and immunostained with monoclonal antibodies against CD138, CD34, CD117, CD42a, hemoglobin, myeloperoxidase, collagen IV, and nerve growth factor receptor. Histologic evaluation included estimates of overall cellularity of hematopoietic tissue, estimates of cellularity in the areas of highest concentration of hematopoietic tissue, myeloid to erythroid ratio, and numbers of megakaryocytes. X-chromosome inactivation analysis was performed on myelolipomas from 11 female patients by polymerase chain reaction. Myelolipomas showed wide variation in cellularity within the lesion (5% to 90%) with no correlation with the patients age. All the myelolipomas demonstrated normal trilineage hematopoiesis and cellular morphology, with few early myeloid precursors, as evidenced by negativity for CD117 and only rare positivity for CD34 antibodies. Most of the myelolipomas (14/18) had markedly increased megakaryocytes compared with normal marrows. The majority of myelolipomas also had a stromal composition and vascular patterns that were different from those of normal bone marrow. X-chromosome inactivation studies demonstrated nonrandom X-chromosome inactivation in 8/11 myelolipomas from female patients. Myelolipomas are morphologically different from the normal bone marrow. The majority of myelolipomas also have nonrandom X-chromosome inactivation, suggesting a clonal origin for these tumors.

HMB-45 Staining in Angiomyolipoma, Cardiac Rhabdomyoma, Other Mesenchymal Processes, and Tuberous Sclerosis-associated Brain Lesions

HMB-45 monoclonal antibody is thought to be highly specific for melanocytic prolifer ations. In a recent study of two cases of hepatic and one case of renal angiomyolipoma, strong staining of lesional cells with this antibody was unexpectedly encountered. In follow-up evaluation, the authors studied 51 additional soft tissue, renal, and brain tumors and tumor-like processes, with emphasis on those with prominent vascular, myogenous, and fatty components or those known to be associated with tuberous sclerosis. Varying degrees of staining with HMB-45 were seen in 17 of the lesions tested. Strong staining with HMB-45 was demonstrated in four renal angiomyolipo mas. Clearly positive results were also obtained in three other processes associated with the tuberous sclerosis complex, including two cardiac rhabdomyomas and one tuberous lesion of the brain. Weak staining of several other mesenchymal and neural lesions was also observed. Electron microscopic studies showed a spectrum of granules within angiomyolipoma, some of which resembled melanosomes and others renin granules. Similar granules were observed in cardiac rhabdomyoma, cerebral tuberous lesions, and in subependymal giant cell astrocytoma. We propose that tuberous scleros is-associated tumors and tumor-like processes are interrelated, and that these and perhaps other mesenchymal proliferations may share components previously believed to be unique to melanocytic lesions. Int J Surg Pathol 1 (3):191-198, 1994

Parathyroid carcinoma: Two new cases — diagnosis, therapy, and treatment

Carcinoma of the parathyroid gland is a disease only rarely encountered in clinical practice. As most of these tumors retain the ability to manufacture active parathyroid hormone, most patients with the disease present with hypercalcemia, many times symptomatic. Since the tumor accounts for only 0.5% to 4.0% of cases of primary hyperparathyroidism, the diagnosis of parathyroid carcinoma may be unsuspected and delayed. The clinical index of suspicion should be elevated if there is a palpable neck mass, an exceptionally high serum calcium level, and/or recurrence of hypercalcemia following surgery.

Meibomian gland adenocarcinoma of the eyelid with preauricular lymph node metastasis

Meibomian gland carcinomas of the eyelid are rare neoplasms, accounting for less than 1% of all eyelid tumors. They usually mimic chalazia and undergo repeated curettage before a definitive diagnosis is made. Although they are relatively slow growing tumors they behave in an aggressive manner, frequently metastasizing to regional lymph nodes. Approximately 50% of the patients who develop metastasis to lymph nodes of the neck will survive five years. We present a case of meibomian gland carcinoma with preauricluar lymph node metastasis, treated with orbital exenteration, superficial parotidectomy, and radical neck dissection.