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Biomedical subjects

Mai P Hoang

Publications and source records attributed to Mai P Hoang.

At least 19 recordsLinked to original sources
PubMed2007

Congenital self-healing reticulohistiocytosis (Hashimoto-Pritzker disease): ten-year experience at Dallas Children's Medical Center.

The real incidence of congenital self-healing reticulohistiocytosis (CSHR) may be underreported because of its high rate of spontaneous resolution and lack of clinical recognition. Currently, there are no criteria other than clinical that can reliably distinguish CSHR from cutaneous involvement by disseminated Langerhans cell histiocytosis (LCH). In this study we investigate the role of E-cadherin, Ki-67, and phosphorylated histone H3 (PHH3) immunohistochemical stains in distinguishing CSHR from disseminated LCH. We found that no significant difference was seen in the histologic features and the expression of E-cadherin, Ki-67, and PHH3 between the two groups; thus supporting the theory that CSHR and LCH represent different ends of a spectrum of the same condition.

Cadherins↗
PubMed2007

Phosphorylated histone H3, Ki-67, p21, fatty acid synthase, and cleaved caspase-3 expression in benign and atypical granular cell tumors.

CONTEXT: Granular cell tumors (GCTs) are classified as benign when none of the following features is present: spindling of the tumor cells, necrosis, diffuse pleomorphism, prominent nucleoli, high nuclear-cytoplasmic ratio, and mitotic rate >2 per 10 high-power fields. It has been suggested that a GCT be classified as atypical when 1 or 2 of these features are seen and as malignant when 3 or more of these are present. In our practice, we do not classify GCTs as malignant in the absence of metastasis. OBJECTIVE: To compare immunohistochemical staining for phosphorylated histone H3 (PHH3), Ki-67 (MIB-1), p21, fatty acid synthase, and cleaved caspase-3 in histologically classified benign and atypical GCTs. DESIGN: We reviewed 25 cases of GCT from our archives and classified 14 as atypical based on histologic features. Immunohistochemical staining for PHH3, Ki-67, p21, fatty acid synthase, and cleaved caspase-3 was performed using standard methods. The number of positive cells for Ki-67, p21, and PHH3 was calculated in 10 consecutive high-power fields in a hot spot. Fatty acid synthase and cleaved caspase-3 cytoplasmic expression was graded from 1 to 3. RESULTS: Ki-67 and PHH3 scores were significantly higher in atypical GCTs. The expression of p21, fatty acid synthase, and cleaved caspase-3 was not significantly different between atypical and benign GCTs. CONCLUSIONS: This study shows that histologic features are reliable in identifying GCTs that have a higher proliferative potential as shown by higher immunoreactivity for Ki-67 and PHH3. These immunostains may help in classifying GCTs in cases where a thorough histologic evaluation is precluded by the small size of a biopsy specimen.

Adult↗
PubMed2006

Cystic panfolliculoma.

Panfolliculoma is a rare follicular neoplasm with differentiation toward both upper (infundibulum and isthmus) and lower (stem, hair matrix, and bulb) segments of a hair follicle. We present an unusual case of cystic panfolliculoma. A 33-year-old Hispanic woman presented with an 8-month history of a 3.0-cm cystic scalp mass. The lesion was excised, and the histologic sections showed a cystic follicular neoplasm that contained corneocytes in basket-woven and laminated array, trichohyalin granules of the inner root sheath, germinative cells, papillae, matrical cells, and "shadow" cells. Cytokeratin 903 and cytokeratin 5/6 immunostains uniformly highlight the tumor cells. Ber-EP4 strongly labels the germinative cells but not the follicular papillae. CD34 labels the surrounding fibrotic stroma and focally the epithelial component.

Adult↗
PubMed2005

Increased ratio of saturated to unsaturated C18 fatty acids in colonic adenocarcinoma: implications for cryotherapy and lipid raft function.

Mammalian fatty acid synthase (FASE) overexpression has been shown in a number of human malignancies including colonic adenocarcinoma. Since FASE synthesizes only saturated fatty acids, we hypothesized that cancer cells have a greater proportion of long-chain saturated fatty acids. We studied and found an unequivocal increase in saturated C18 fatty acid (stearic acid) in colonic adenocarcinoma compared to adjacent normal colonic mucosa. The increase is even more striking when measured as a ratio of stearic acid to the unsaturated C18 fatty acids (oleic acid and linoleic acid). This change in fatty acid composition of the cancer cells should significantly alter their physical and biological properties. The increase in relative proportion of saturated fatty acids should make the cancer cells more susceptible to cryodamage and measurement of fatty acid composition of cancer cells may help individualize the temperature for cryotherapy. Also, the lipid alterations may affect the structure and functions of lipid rafts, which may enable the cancer cells to affect signaling mechanisms such as those involved in cell growth and apoptosis. Dietary or therapeutic interventions targeting lipid rafts may thus be an option for cancer treatment.

Adenocarcinoma↗
PubMed2005

Lipedematous alopecia: an unusual sequela of discoid lupus, or other co-conspirators at work?

BACKGROUND: Lipedematous alopecia is a rare entity of uncertain origin characterized by a boggy scalp and varying alopecia. Of 11 cases in the literature, 7 occurred in African American women. Classic histopathologic findings include increased subcutaneous tissue, varying inflammation, and an absence of mucin. Some have sought to distinguish this disorder from lipedematous scalp, a condition with similar tactile features, but without alopecia. OBSERVATION: We describe a case of lipedematous alopecia in an African American woman who also had findings of discoid lupus erythematosus. Such an observation has not been made previously, and may provide insight into the cause of lipedematous alopecia. This case is contrasted with a case of lipedematous scalp. CONCLUSION: Some cases of lipedematous alopecia may represent an unusual consequence of discoid lupus erythematosus. Alternatively, it is possible that lipedematous scalp is a benign condition observed in some patients, and that a second insult results in alopecia. Finally, lipedematous alopecia might share some histopathologic and/or clinical findings with discoid lupus erythematosus, or it may represent a nonspecific reaction pattern to chronic injury.

Black or African American↗
PubMed2005

Completely regressed primary cutaneous malignant melanoma with nodal and/or visceral metastases: a report of 5 cases and assessment of the literature and diagnostic criteria.

BACKGROUND: Partial regression of primary cutaneous malignant melanoma is not uncommon and may predict a higher likelihood of metastasis and decreased survival. Complete histologic regression of a primary cutaneous melanoma is a rarer occurrence, with only 34 cases reported in the English-language or English language-summarized literature. OBSERVATION: We detail 4 cases of complete histologic regression of primary cutaneous melanoma, discovered at presentation with metastatic disease. A pigmented lesion or its remnant, coupled with historical information, was strongly suggestive of cutaneous melanoma. Histologic examination of the lesions, using multiple levels and immunohistochemical stains, failed to reveal residual melanoma. Our cases are typified by the presence of metastasis of melanoma to regional lymph nodes, with the absence of other suspect skin lesions or malignancies. In addition, we present a fifth case involving a completely regressed lesion on the scalp in a patient with cerebral melanoma metastasis and comment on the implications of this case to accepted diagnostic criteria, proposing that consideration of modification to the criteria be entertained. CONCLUSION: The concept of completely regressed primary cutaneous melanoma is reviewed and the literature critically appraised. When one considers a diagnosis of completely regressed primary cutaneous melanoma, cases must be well documented and biopsy proven. Patients with metastatic melanoma and an occult primary lesion require a thorough skin examination, with serious consideration given to the possibility of completely regressed cutaneous melanoma.

Adult↗
PubMed2005

Spitz nevi and atypical Spitz nevi/tumors: a histologic and immunohistochemical analysis.

A subset of Spitz nevi poses substantial diagnostic difficulty, even among experts, due to its resemblance to malignant melanoma. These lesions are termed atypical Spitz nevi/tumors and there is currently a lack of objective criteria for predicting their biologic behavior. We compared the expression of Ki-67, p21, and fatty acid synthase by immunohistochemistry in 10 atypical Spitz nevi, 28 typical Spitz nevi, 19 compound melanocytic nevi and 18 invasive malignant melanomas. There was a progressive increase in fatty acid synthase cytoplasmic expression with statistically significant differences observed between Spitz nevi and atypical Spitz nevi (P=0.003) and between atypical Spitz nevi and malignant melanoma (P<0.050). Ki-67 nuclear staining was lower in both typical and atypical forms of Spitz lesions than in malignant melanoma (P<0.001). The degree of P21 nuclear expression in atypical Spitz nevi was not significantly different than in Spitz nevi, but was significantly greater than expression in conventional nevi and approached significance after multiple comparisons corrections for malignant melanoma. Thus, a high level of P21 expression makes a tumor more likely to be a typical or atypical Spitz nevus than a malignant melanoma, especially when coupled with a low Ki-67 index and weak expression of fatty acid synthase. These immunohistochemical observations support the concept that atypical Spitz nevi are distinct lesions of borderline biologic behavior residing between Spitz nevi and malignant melanoma. The study also compared a large array of histologic features of 16 cases of typical Spitz nevi in children with 12 typical Spitz nevi in adults. The adult lesions were significantly more likely to be intradermal and to display dermal fibroplasia, but were histologically similar to their pediatric counterparts in all other respects.

Adolescent↗
PubMed2005

Fatty acid synthase expression in cutaneous melanocytic neoplasms.

Mammalian fatty acid synthase is a multifunctional enzyme complex involved in de novo synthesis of saturated fatty acids, and inhibitors of fatty acid synthase are being evaluated as potential therapeutic agents. Increased fatty acid synthase expression has been demonstrated in subsets of malignancies, including colon, breast, endometrium, prostate and ovarian carcinomas, and recently malignant melanomas. We evaluated the immunohistochemical expression of fatty acid synthase in 155 cutaneous melanocytic lesions. They included 30 congenital nevi, 19 compound nevi, 40 Spitz nevi, 48 primary melanomas, and 18 metastatic melanomas. Fatty acid synthase expression was stronger in malignant melanomas in comparison to conventional nevi and Spitz nevi, and was the highest for metastatic melanoma. Of the primary malignant melanomas, mean fatty acid synthase scores were significantly greater for Clark levels IV and V compared to Clark levels I and II (P<0.001). In addition, melanomas with Breslow thickness 0.75-1.50 mm and >1.50 mm showed significantly higher mean fatty acid synthase scores compared with those with Breslow thickness <0.75 mm (P=0.013 and <0.001, respectively). Of interest, congenital melanocytic nevi also showed strong fatty acid synthase expression, similar to that seen in metastatic melanoma. This may represent persistence of or regression to a fetal phenotype since normal fetal tissues are known to express high levels of fatty acid synthase.

Adolescent↗
PubMed2005

Pruritic urticarial papules and plaques of pregnancy with unusual and extensive palmoplantar involvement.

BACKGROUND: Pruritic urticarial papules and plaques of pregnancy (PUPPP) is a specific dermatosis of pregnancy common to primigravid women in the third trimester. The rash usually begins on the lower abdomen within striae and spreads to the proximal extremities. Involvement of face, palms, and soles is unusual. Although intensely pruritic, the fetus is unaffected, and the condition does not usually recur. It can be difficult to distinguish PUPPP from pemphigoid gestationis, an autoimmune bullous disorder with potential fetal consequences that may recur with subsequent pregnancy, menses, or hormonal therapy. CASE: A young secundagravida at 36 weeks of gestation with monochorionic twins presented with a 3-week history of a pruritic papular eruption that began on the abdomen and spread to the extremities. She had extensive involvement of the distal extremities, including the palmoplantar surfaces, with small vesicles of 2-4 mm on acral skin. Because of her unusual presentation, she was thought initially to have pemphigoid gestationis. Subsequent dermatological evaluation and a biopsy confirmed the diagnosis of PUPPP. Shortly after admission she delivered 2 healthy male infants, and her rash cleared with conservative management. CONCLUSION: Pruritic urticarial papules and plaques of pregnancy often, but not always, spares the face, palms, and soles. Small vesicles can occur in PUPPP, but formation of true bullae is not observed. Careful dermatological examination and cutaneous biopsy can assist in differentiating PUPPP from pemphigoid gestationis, which is essential for treatment and prognosis.

Adrenal Cortex Hormones↗
PubMed2005

Subcutaneous phaeohyphomycosis caused by Cladophialophora bantiana.

Primary subcutaneous phaeohyphomycosis can rarely be caused by Cladophialophora bantiana, and we present the histologic and culture findings of such a case. A 32-year-old African American woman with systemic lupus erythematosus presented with a 2-year history of multiple, recurrent, tender, and ulcerated skin nodules with purulent drainage on her upper back. Histologic sections of the excision demonstrated features of phaeohyphomycosis. Culture findings were characteristic of C bantiana. Of interest, at age 10 she had sustained traumatic implantation of wood splinters into this area during a tornado, yet clinical symptoms of a subcutaneous infection did not manifest until she developed lupus erythematosus at age 27. Our case highlights the role of trauma and immunosuppression in the pathogenesis of subcutaneous phaeohyphomycosis.

Adult↗
PubMed2005

Psoriasis guttata with palmoplantar involvement clinically mimicking secondary syphilis.

Papulosquamous eruptions involving the palms and soles are thought to be particularly suggestive of secondary syphilis. Alternative diagnoses exist, however, and include psoriasis guttata, atypical pityriasis rosea, and pityriasis lichenoides chronica (PLC). We describe the case of a patient with an abrupt onset of psoriasis guttata and extensive palmoplantar involvement. Results of serologic testing were negative for treponemicidal antibodies. Results of histopathologic examination demonstrated psoriasiform dermatitis with neutrophils in the epidermis; plasma cells were absent. Spirochetes were not demonstrated in a tissue sample using silver or immunohistochemical stains for Treponema pallidum. A broad differential diagnosis is required when evaluating papulosquamous eruptions with palmoplantar involvement. Although not well referenced in the medical literature, psoriasis guttata can indeed cause palmoplantar lesions that mimic those of secondary syphilis.

Adult↗