Biomedical subjects
Publications and source records attributed to M A Hurt.
This article describes a method of uniform gross-room sectioning of skin biopsy specimens, especially excisional biopsy specimens, to insure even thickness and maximum control of the tissue before paraffinization. This is accomplished by sequentially halving portions of the specimen after each cut as opposed to serially cutting the skin from one end to the other.
A 31-year-old Hispanic man presented in the pancytopenic phase of acute myelocytic leukemia and was treated with the chemotherapeutic agents mitoxantrone and cytarabine. After 5 days, an erythematous, blanching, papular, crusted eruption developed on his forehead, chest, and legs. Some lesions showed confluence and all were at the same developmental stage. Clinical diagnoses included necrotizing vasculitis and sepsis. A biopsy specimen revealed widespread noninflammatory syringometaplasia of eccrine ducts. Well-developed intercellular bridges and eosinophilic cytoplasm were seen within the metaplastic cells; apoptoses and occasional mitoses were present. This process is distinct and probably occurred secondary to direct toxic injury from the chemotherapeutic drugs. Because similar changes have occurred in patients with neutrophilic eccrine hidradenitis, we believe our patient represents an example of the noninflammatory end of the spectrum of chemotherapeutic eccrine gland reactions.
Two patients with eccrine syringofibroadenomas were studied. The first patient had a 3-year history of asymptomatic, unilateral, linear, moist mosaic plaques of the lower part of the left leg and foot; the second patient had a solitary papule on the back. Histologically, both tumors exhibited superficial elongated strands of eccrine ductal epithelium containing occasional lumina lined by an eosinophilic cuticle. The stroma was loose, myxoid, and fibrovascular. The secretory portions of the eccrine glands were ectatic in the first patient but were not seen in the second patient. We believe these lesions represent acrosyringeal hamartomas (nevi), although some authors interpret them as adenomas. The literature seems to indicate that lesions with similar histologic features may be solitary, multiple, or combined with other neoplasms; in other cases, the lesions may possibly represent an unusual morphologic expression of hidrotic ectodermal dysplasia.
This report describes four cases of a previously undocumented circumscribed idiopathic inflammatory fibrosclerotic lesion of the skin. The lesions occurred in two black women and two white men; they had been apparent from months to a year. The nodules were solitary; two were located on the arm, one on the calf, and one on the posterior neck. The clinical diagnoses included nodules, keratinous cyst, pilar tumor, pilomatricoma, vascular leiomyoma, dermatofibroma, and metastatic carcinoma. The lesions were grossly white, homogeneous, and circumscribed; one was located in the superficial subcutis and three in the reticular dermis. Histologically, they were sharply circumscribed and surrounded by a dense peripheral rim of lymphocytes and plasma cells. Peripheral germinal centers were noted in two cases. All cases had variable amounts of fibrosis centrally, giving them the low-power appearance of lymph nodes; however, no subcapsular or medullary sinuses were found. In the center of the lesions, the mononuclear infiltrate was accompanied by eosinophils and neutrophils. Virtually imperceptible vasculature was noted in portions of three lesions; in the fourth lesion, high endothelial venules were seen in the lymphoid portions, and "targetoid" perivascular sclerosis was seen in the central portions. There appears to be a transition from the early, mostly inflammatory, lesions to the sclerotic ones. The process seems to be reactive in nature. No obvious local or systemic etiology was found in our series, and follow-up of 2 to 5 years has been noncontributory. These mixed-cell proliferations resemble the extracutaneous masses that have been described in numerous viscera--particularly the lung--as "inflammatory pseudotumors" or "plasma cell granulomas." In our opinion, these lesions also bore a superficial resemblance to cutaneous lymphoid hyperplasia secondary to insect bites. Other differential diagnostic considerations include dermatofibroma, nodular fasciitis, Kimura's disease, epithelioid (histiocytoid) hemangioma, and reactive lymph nodes.
Leiomyoma of the breast parenchyma proper is a rare neoplasm. This tumor occurs predominantly in late middle-aged women and can be clinically difficult to discern from carcinoma. Mammographically, the tumor lacks typical features of carcinoma, but this possibility cannot be absolutely excluded. Immunohistochemical, ultrastructural, and DNA characteristics are reported in a new case. Mammographic findings are reported for the first time. Immunoperoxidase findings with antibodies to muscle-specific actin, desmin, vimentin, S-100 protein, and cytokeratins, as well as the ultrastructural features, suggest a pure smooth muscle cell origin and not a myoepithelial cell origin.
We describe five patients with distinct posttraumatic subcutaneous nodules that usually evolved for several months before diagnosis. The nodules occurred in the subcutis of the elbow or hip of women, 33 to 74 years old, and in the hip of a 16-year-old boy. Histologically the fully developed lesions were totally or nearly totally encapsulated by thin, fibrous tissue. All contained well-preserved outlines of nonnucleated adipocytes; there was no inflammation or saponification. In one patient's lestion the viable subcutaneous tissue merged into several partially encapsulated necrotic nodules. In another case a smaller nodule was found within a larger, mostly calcified nodule. Names such as nodular-cystic fat necrosis, mobile encapsulated lipoma, and encapsulated necrosis have been offered to designate the lesion. Its pathogenesis seems to be related to trauma, rapid vascular insufficiency, and subsequent fibrous capsule formation. Many previously reported patients, however, had no history of trauma. The lesion must be distinguished histologically from lipoma, angiolipoma, alpha 1-antitrypsin deficiency-associated panniculitis, membranous fat necrosis, and pancreatic fat necrosis. Simple excision is the treatment of choice.
Transitional-cell carcinoma to the mandible is an uncommon occurrence. Only three cases have been reported in the literature. This is a case report of such a metastasis, the first diagnosed by fine-needle aspiration. Emphasis is placed on the cytologic features of the tumor cells.
We report 6 cases of an immature variant of trichoepithelioma which histologically appears to show differentiation toward the primitive hair germ. The lesions presented in mature adults (mean age 44 years). Four occurred in men and 2 in women. Four lesions occurred on extremities, an unusual location for trichoepitheliomas. Histologically, the lesions were characterized by well-circumscribed, but unencapsulated, dermal collections of small tumor lobules composed of basaloid cells with invaginations resembling primitive dermal hair papillae. There was no adenoidal growth pattern or horn cyst formation. The separation of the immature lesions from those of classical trichoepithelioma and basal cell carcinoma can be made if multiple morphological features are considered; no one particular finding is diagnostic. The major differential features between the immature trichoepithelioma and basal cell carcinoma are circumscription, tumor lobule uniformity, occasional immature hair germs, and lack of retraction artifact of the tumor lobules from the stroma. The differential features between the immature and classical trichoepithelioma are less conspicuous. The immature form typically exhibits no horn cysts, displays fewer primitive hair structures, and lacks the adenoidal growth patterns of the tumor lobules which are usually present in the classical trichoepitheliomas.
Squamous metaplasia arising in nonneoplastic breast parenchyma is reportedly rare. We present a unique case which occurred following severe blunt trauma to the right breast of a 59-yr-old woman. The lesion contained sheets of squamous cells with a lobular growth pattern, bland cytology with few mitoses, and keratin and keratohyalin granules. It bore a striking resemblance to squamous (necrotizing) sialometaplasia of the salivary gland in that it exhibited lobular, pseudocarcinomatous growth. The patient has remained free of disease 49 mo after segmental resection of the lesion. Four previous cases of squamous metaplasia of the female breast have been reported, though none presented with a history of trauma or previous surgical manipulation. It is important to differentiate this entity from pure squamous cell carcinoma, and metaplastic change in ductal breast carcinoma, fibroadenoma, and other lesions. Breast aspiration biopsies revealing squamous cells cannot exclude carcinoma; thus, caution must be exercised.
Several independent, spontaneous rifampin-resistant mutants of Bacillus subtilis were isolated and found to have an increased resistance to trimethoprim, an inhibitor of dihydrofolate reductase. This increased resistance in the rif mutants was the result of a specific threefold increase in the activity of dihydrofolate reductase, since six other enzymes examined remained unchanged. This increased level of dihydrofolate reductase and the trimethoprim resistance were cotransformed (100%) with the rif marker. These results suggest that the RNA polymerase is altered in its recognition of the gene that specifies dihydrofolate reductase.