Impact of Mobile Phone Interference on Gamma Camera Performance

INTRODUCTION

Electromagnetic interference (EMI) due to a mobile phone device has been reported to produce a detrimental effect on the function of a gamma camera system. This effect provides evidentiary support of potential bans or restrictions regarding mobile phone use within a nuclear medicine department.

METHODOLOGY

A 3G Apple iPhone 6 was tested against a thyroid phantom in four operating modes, in three positions. Testing was carried out on a Siemens E-Cam gamma camera and a GE Discovery 670 SPECT/CT gamma camera. The protocols were standardized for operation on both systems with static images obtained for assessment. The static images were arithmetically assessed by means of subtraction from a baseline image, for results of potential EMI to be determined following comparison to the baseline image.

RESULTS

Initial assessment of static images acquired provided no abnormality between modes and positions. Following the application of arithmetic processes, the inferior right lobe presented with an increased ring of activity on activation of mobile signals regardless of position when tested on the Siemens E-Cam gamma camera. When compared to the GE Discovery 670 SPECT/CT gamma camera, these results did not appear to be present. This was confirmed numerically as a statistical significant difference was noted in count differences between the Siemens E-Cam and GE Discovery (P = 0.0004).

CONCLUSION

The function of a gamma camera has the potential to be influenced by EMI produced by mobile phone devices. Further investigation is warranted employing SPECT acquisition to assess the potential for amplification of errors.

Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes

Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts.

Single-photon Emission Tomography/Computed Tomography Delineation of Freiberg Infraction

The role of nuclear medicine diagnostic bone scanning is well established and the influence of coregistration between single-photon emission computed tomography and computed tomography well documented. This case provides an insight into a less frequently encountered pathology in which the combination of single-photon emission computed tomography and computed tomography permitted the differentiation of potential pathology.

Mycosis fungoides ? a review of the management of 28 patients and of the recent literature

BACKGROUND

Mycosis fungoides is an uncommon cutaneous T-cell lymphoma characterized by malignant monoclonal proliferation of T-helper lymphocytes. Its course is variable with a potential for lymphatic and hematogenous involvement. We report the investigations, staging, treatment, follow-up, and outcome of 28 patients. This is the first such study reported from Ireland.

METHODS

Twenty-eight patients with mycosis fungoides (14 women, 14 men; average age, 52.5 years) were reviewed over 12 years in the dermatology clinic which assesses an average of 4500 patients per year. All mycosis fungoides patients were referred from their family physicians. The diagnosis was made in all cases from a combination of clinical findings, histology, and immunohistochemistry. TNM staging revealed 11 patients at diagnosis stage IA (T1), 12 at stage IB (T2), four at stage IIB (T3), and one at stage III (T4).

RESULTS

The usual male preponderance was not found. Eight patients needed multiple biopsies to establish the diagnosis. Detailed investigations were not useful in the early stages. Patients were followed up over a 12-year period. Thirteen patients died as a result of cutaneous lymphoma. Two patients with stage IA disease progressed rapidly and died, a feature reported in only 10% of patients at this stage. Five patients showed unusual features, including a long history prior to presentation, the development of the rarely reported bullous mycosis fungoides, and aggressive disease beginning at a young age.

CONCLUSIONS

Mycosis fungoides is rare; we reviewed 28 patients over 12 years. The prognosis is poor at the later stages; 13 patients died. Two patients who died were unusual in that they rapidly progressed from stage IA disease; however, in the majority of patients with this stage, the prognosis is excellent. Detailed investigations were unhelpful in early stage disease. Close clinical follow-up is essential to identify disease progression.

Core set approach to reduce uncertainty of gene trees

Background

A genealogy based on gene sequences within a species plays an essential role in the estimation of the character, structure, and evolutionary history of that species. Because intraspecific sequences are more closely related than interspecific ones, detailed information on the evolutionary process may be available by determining all the node sequences of trees and provide insight into functional constraints and adaptations. However, strong evolutionary correlations on a few lineages make this determination difficult as a whole, and the maximum parsimony (MP) method frequently allows a number of topologies with a same total branching length.

Results

Kitazoe et al. developed multidimensional vector-space representation of phylogeny. It converts additivity of evolutionary distances to orthogonality among the vectors expressing branches, and provides a unified index to measure deviations from the orthogoality. In this paper, this index is used to detect and exclude sequences with large deviations from orthogonality, and then selects a maximum subset ("core set") of sequences for which MP generates a single solution. Once the core set tree is formed whose all the node sequences are given, the excluded sequences are found to have basically two phylogenetic positions on this tree, respectively. Fortunately, since multiple substitutions are rare in intra-species sequences, the variance of nucleotide transitions is confined to a small range. By applying the core set approach to 38 partial env sequences of HIV-1 in a single patient and also 198 mitochondrial COI and COII DNA sequences of Anopheles dirus, we demonstrate how consistently this approach constructs the tree.

Conclusion

In the HIV dataset, we confirmed that the obtained core set tree is the unique maximum set for which MP proposes a single tree. In the mosquito data set, the fluctuation of nucleotide transitions caused by the sequences excluded from the core set was very small. We reproduced this core-set tree by simulation based on random process, and applied our approach to many sets of the obtained endpoint sequences. Consequently, the ninety percent of the endpoint sequences was identified as the core sets and the obtained node sequences were perfectly identical to the true ones.

Protein tyrosine phosphatase genes downregulated in melanoma

Phospho-tyrosine levels are increased in melanoma, apparently consistent with reports of elevated protein tyrosine kinase activity. Some protein tyrosine kinases are encoded by oncogenes and have been implicated in melanoma genesis. Decreased protein tyrosine phosphatase activity may also increase phospho-tyrosine. Protein tyrosine phosphatase genes are candidate tumor suppressors and loss of expression may contribute to melanoma genesis. Here we survey protein tyrosine phosphatase expression in pigment cells. Protein tyrosine phosphatase genes were cloned by reverse transcriptase polymerase chain reaction using degenerate primers based upon conserved sequences within the phosphatase catalytic domain. Reaction products were cloned and sequenced: 118 and 113 partial protein tyrosine phosphatase products were isolated from normal melanocytes and melanoma cells, respectively. Northern blotting analysis was used to study expression of 15 protein tyrosine phosphatase genes. Expression of PTP-kappa and PTP-pi was absent or downregulated in more than 20% of melanoma cell lines and in some unmanipulated melanoma biopsies. These closely related enzymes are members of the 2B receptor protein tyrosine phosphatase family previously implicated in contact inhibition. Loss of protein tyrosine phosphatase expression may contribute to the abnormal tyrosine phosphorylation seen in melanoma; these genes are candidate tumor suppressors.

Suspected skin malignancy: a comparison of diagnoses of family practitioners and dermatologists in 493 patients

BACKGROUND

In the Irish health system, dermatology patients present to their family practitioner for diagnosis and treatment, and are referred to a dermatologist for a second opinion where diagnosis is in doubt or when there has been therapeutic failure. The level of expertise in dermatology amongst family practitioners varies considerably.

AIM

To compare the diagnoses of general practitioners and dermatologists over a selected period in patients with a possible diagnosis of skin cancer.

METHODS

Four hundred and ninety-three patients were seen by one of two dermatologists over a 1-year period at a rapid referral clinic for patients suspected by their family practitioners of having unstable or possibly malignant skin lesions; 213 of these patients had a diagnosis made on clinical examination by the dermatologist, while 264 had diagnostic or therapeutic biopsies performed; 16 patients defaulted on surgery.

RESULTS

The diagnoses of the family practitioners agreed with the diagnoses of the dermatologists on patients diagnosed clinically in 54% of cases. Thirty-eight patients had histologically proven skin malignancy. These were diagnosed accurately by the referring family practitioner in 22% of patients, while the dermatologists made the correct diagnosis prior to biopsy in 87%.

CONCLUSIONS

In over 50% of cases diagnosed clinically, the dermatologist and family practitioner agreed. Histologically proven skin cancers were diagnosed accurately in only 22% of cases by family practitioners, compared to 87% of cases by dermatologists. Specific areas of diagnostic difficulty for family practitioners include benign pigmented actinic and seborrheic keratoses, squamous cell carcinoma, and melanoma. Postgraduate education for family practitioners should be directed towards these areas of deficiency. Dermatologists had difficulty distinguishing pigmented actinic keratoses from melanoma.

Choice of management strategy for colorectal cancer based on a diagnostic immunohistochemical test for defective mismatch repair

BACKGROUND

Despite intensive research into the molecular abnormalities associated with colorectal cancer (CRC), no diagnostic tests have emerged which usefully complement standard histopathological assessments.

AIMS

To assess the feasibility of using immunohistochemistry to detect replication error (RER) positive CRCs and determine the incidence of RER positivity within distinct patient subgroups.

METHODS

502 CRCs were analysed for RER positivity (at least two markers affected) and/or expression of hMSH2 and hMLH1.

RESULTS

There were 15/30 (50%) patients with metachronous CRCs, 16/51 (31%) with synchronous CRCs, 14/45 (31%) with a proximal colon carcinoma, and 4/23 (17%) who developed a CRC under the age of 50 showed RER positivity. However, 0/54 patients who developed a solitary carcinoma of the rectum/left colon over the age of 50 showed RER positivity. Immunohistochemical analysis revealed that 66/66 (100%) RER positive carcinomas were associated with complete lack of expression of either hMSH2 or hMLH1. This correlation was confirmed using a further 101 proximal colon carcinomas. Patients with a mismatch repair defective carcinoma showed improved survival but a 5.54 times relative risk of developing a metachronous CRC. A prospective immunohistochemical study revealed 13/117 (11%) patients had a mismatch repair defective carcinoma. A fivefold excess of hMLH1 defective cases was noted.

CONCLUSIONS

All RER positive carcinomas were identified by the immunohistochemical test. This is the first simple laboratory test which can be performed routinely on all CRCs. It will provide a method for selecting patients who should be investigated for HNPCC, offered long term follow up, and who may not respond to standard chemotherapy regimens.

Linear IgA disease--a review of four patients

Four cases of Linear IgA Disease (LAD) seen over a five year period are reviewed and our most recent LAD patient is described in detail. We summarise data on our patients and outline clinicopathologic features, aetiology and management of this unusual but important condition.

A clinicopathological correlation of 134 stage 1 and 79 non-invasive cutaneous melanomas presenting over a decade (1984-1993) at the Mater Misericordiae Hospital, Dublin

In a study of malignant melanoma during the period 1984-1993, 134 (63 per cent) had invasive melanoma and in 79 (37 per cent) melanoma was confined to the epidermis (in situ). There was female predominance, F: M = 2.4 : 1, a family history of melanoma in 1.5 per cent, a mean age at diagnosis of 50 yr. Females presented a decade earlier than males on average. Over half of invasive melanomas in females occurred on lower limbs; 40 per cent of lesions in males occurred on the trunk. Almost one third of lesions in males and over two thirds in females occurred in sun exposed area. Sixty per cent of invasive lesions were of the superficial spreading type and half of all lesions were histologically thin [less than 1.5 mm vertical depth]. Surprisingly, median lesion thickness was lower in males, probably reflecting the greater frequency of nodular lesions in females compared to males (36 per cent -v- 24 per cent). The marked increase in the number of invasive melanoma patients presenting in the second half of the decade studied (treble that of the first half) probably reflects an increase in melanoma incidence. Over the decade no change in invasive melanoma type, anatomical site or histological thickness was noted, the latter suggesting a failure to diagnose melanoma at an increasingly earlier stage. An official melanoma public education programme is required, particularly as half of the patients delayed 1 yr or more before seeking medical advice. However it is encouraging that, of the invasive melanomas, 30 per cent were small (< 10 mm), 50 per cent were histologically thin and that 37 per cent of all melanomas were in situ. The melanoma-in-situ group had a similar gender ratio and mean age at diagnosis to the invasive melanoma patients but lesions were smaller, were predominantly on the head, neck and limbs with lentigo melanoma as the commonest type.

Persistent infection of the chin with an unusual skin pathogen (Streptococcus milleri): a sign of intraoral carcinoma

Streptococcus milleri is a commensal of the oropharynx and gastrointestinal tract which is not generally associated with skin disease. We now report a patient who presented with a pustular mass of the chin with lower lip anaesthesia. He was initially thought to have sycosis barbae, but response to treatment was poor and lesional swabs repeatedly cultured S. milleri. After some delay, squamous cell carcinoma of the mouth, involving the mandible and overlying skin, was detected. We consider that the S. milleri either invaded through the tumour from the mouth or root canal or colonized the skin from saliva dribbled over the numb lower lip. Isolation of an unusual organism and numbness of the chin are features that should suggest the need for early radiography.

Dermatitis Herpetiformis: a review of fifty-four patients

A review of 54 patients with dermatitis herpetiformis presenting between 1984-1993 to The Regional Centre of Dermatology, Mater Misericordiae Hospital was undertaken. All patients had skin lesions clinically and histologically typical of dermatitis herpetiformis. Deposition of granular IgA at the dermoepidermal junction on direct immunofluorescence was present in each case. The average age of onset was 41.8 yr, patients having symptoms for an average of 1.6 yr before diagnosis. Six patients had a prior history of coeliac disease. Two patients had a family history of dermatitis herpetiformis, a father and son who were both propositi in this study. Small bowel biopsy was performed on 35 patients, 71.4 per cent of them showing evidence of villous atrophy. All patients were controlled on a gluten free diet or by dapsone or a combination of these. None of the patients experienced serious adverse effects of therapy, nor did any develop lymphoma of the small bowel with a mean follow up period of 4.2 yr (range 1-10 yr).

Idiopathic anaphylaxis

Three cases of idiopathic anaphylaxis are presented. This condition represents a rare but important cause of collapse. The development of atrial fibrillation, reported here for the first time, may lead to diagnostic difficulties. Early recognition and treatment is essential and will result in a good prognosis.

Acromegaly and cutis verticis gyrata

Images

A quantitative immunohistochemical evaluation of lentigo maligna and pigmented solar keratosis

Pigmented solar keratosis (PSK) is sometimes clinically indistinguishable from lentigo maligna, a form of malignant melanoma in situ. Occasionally histologic diagnosis is also difficult. Accurate diagnosis is essential, as the treatment and prognosis for each condition differs considerably. To determine whether there was a significant overlap in the number of melanocytes in these sun-damaged skin lesions, or whether immunohistochemistry might be helpful in the differential diagnosis, the authors examined skin biopsy specimens from 26 patients with obvious lentigo maligna and 15 patients with PSK using 3 monoclonal antibodies (HMB-45, NK1C3, and vimentin) and 1 polyclonal antibody (S-100 protein). Formalin-fixed paraffin sections were immunostained with each of the above antibodies, and immunopositive cells per mm2 of epidermis were counted. The difference between lentigo maligna and PSK counts was statistically significant at a level of P < .0001; furthermore, there was almost no overlap between the two groups. The sensitivity for the diagnosis of lentigo maligna was high with all antibodies. However, HMB-45 had the highest sensitivity and the lowest false-positive rate and was visually most pleasing. Using a cut-off count of 60 cells per mm2 of epidermis, HMB-45 had a sensitivity of 96% and a 0% false-positive rate. In this study, lentigo maligna was easily differentiated from PSK. The real value of immunohistochemistry in the differential diagnosis of these pigmented lesions should be tested in a prospective study using cases that are difficult to diagnose by routine light microscopy.

The role of computed tomography and sonography in acute bullous pemphigoid

We report acute bullous pemphigoid occurring in an elderly female patient in whom abdominal sonography and computed tomography (CT) examinations revealed the presence of occult hepatic and splenic metastatic deposits from a primary pancreatic carcinoma. In the majority of cases bullous pemphigoid is a self limiting auto-immune disorder occurring in the absence of systemic disease. An association with visceral malignancy has been described by previous authors but the role of computed tomography and sonography in diagnosing occult malignancy and the subgroup of patients with pemphigoid in whom this should be undertaken has not been highlighted.

Paraneoplastic pyoderma gangrenosum

Pyoderma Gangrenosum (PG) is often associated with an underlying disease. PG as a paraneoplastic disease is illustrated by the presentation of four patients with malignancy of myeloproliferative origin and PG. An associated malignancy is found in approximately 7% of patients with PG, most commonly haematologic in nature and in particular leukaemia. Clinically the PG is often of the superficial bullous variant and is associated with a poor prognosis.

HLA typing in Irish psoriatics

Histocompatibility antigens were determined in 93 unrelated Irish psoriatic patients. The results were compared with the HLA profiles of 253 healthy unrelated Irish controls. There was a statistically significant increase in HLA B17 (P < 0.0001), B13 (P = 0.02), and B27 (P = 0.015) among the psoriatic patients. The frequency of HLAB8 (P = 0.002) and HLA B12 (P = 0.001) was lower than expected. When the subgroup of patients with psoriatic arthritis was evaluated separately, it was noted that the increase in HLAB27 was highly statistically significant (P < 0.0001). The relative risks of an Irish patient carrying the major psoriasis associated alleles of developing psoriasis are documented;-possession of the HLA B17 and B13 antigens conferring a risk of developing psoriasis vulgaris of 6.08 and 2.9 respectively. Further values for psoriatic subsets are presented. This is the first report of HLA typing in an Irish psoriatic population. The findings are discussed and compared with other population groups.

Labial melanotic macule: a clinical, histopathologic, and ultrastructural study

BACKGROUND

The labial melanotic macule (LMM) is a recently described pigmentary anomaly that may simulate malignant melanoma.

OBJECTIVE

Our purpose was to define the LMM clinically, histologically, and immunohistochemically in a large group of patients.

METHODS

We describe the clinical features of 36 LMMs in 29 patients (aged from 4 to 79 years, 4 male, 25 female) seen during the past 4 years. Histopathologic findings in 21 of these patients are discussed. Seventeen lesions were immunostained with HMB-45 monoclonal antibody, and electron microscopy was performed on eight lesions.

RESULTS

The majority of patients were women and had solitary lesions on the lower lip with the mean age of onset of 30 years. Histologically prominent basilar hyperpigmentation accentuated at the tips of the rete ridges was present without atypia or nevoid formation. Immunohistochemical studies showed that all intralesional melanocytes were HMB-45 negative, supporting their benign nature. Ultrastructurally, numerous stage III and IV melanosomes clustered within basal keratinocytes and papillary dermal melanophages were found.

CONCLUSION

The LMM is a clinically and histologically distinctive benign pigmentary anomaly.

Autobiographical memory and problem-solving strategies of parasuicide patients

Recent research has noted the tendency of parasuicide patients to retrieve over-general autobiographical memories. Separate studies suggest problem-solving deficits within this group. The present study was concerned first with replicating these findings and, secondly, with developing a model of the relationship between over-general memory recall and poor problem-solving abilities in parasuicide patients. Anger and hopelessness were measured as markers for mood. In line with the hypotheses, the parasuicide group (N = 12) produced significantly over-general memories in contrast to a matched control group (N = 12). This occurred significantly in relation to positive cues, and latency to first responses was significantly delayed in the parasuicide group. The parasuicide group also provided fewer and less-effective problem-solving strategies than the control group, and a significant association was found between low effectiveness of problem-solving strategies and over-general memory recall in the parasuicide group. Anger and hopelessness levels were significantly higher within the parasuicide group in line with previous findings. The clinical implications of these findings are discussed.

Familial non-diabetic necrobiosis lipoidica

Necrobiosis lipoidica (NL) is a cutaneous disorder with distinctive clinical and morphologic characteristics. It is associated with diabetes mellitus in two thirds of cases. The aetiology and pathogenesis of NL are unknown but familial cases of NL seem to be extremely rare. We report the occurrence of NL in two sisters with normal glucose tolerance.

Polymorphic light eruption with contact and photocontact allergy

We report a patient with long-standing polymorphic light eruption (PLE) who developed a photocontact allergy to mexenone and several contact allergies. The occurrence of multiple contact and photocontact allergies in PLE and the possible relationship of such allergies to the pathogenesis of PLE are discussed.

The effect of a pre-appointment questionnaire on clinical psychologist attendance rates

A 12-page, psychodynamically-formulated questionnaire is sent routinely to people referred to a clinical psychology service. This study examines its effect on attendance rates at initial appointments. A group of patients who were sent the questionnaire was compared to two control groups. There were indications that those who were sent the questionnaire were more likely than controls to attend. The result failed to reach statistical significance at the 5 per cent level, but, using a more conservative criterion, those who were sent the questionnaire were significantly more likely than controls to make contact--either by attending or actively cancelling their appointment--rather than simply failing to turn up.

Granulomatous hepatitis in secondary syphilis

An unusual case of a well-documented granulomatous hepatitis in secondary syphilis in a 47-year-old male is presented. This hepatic pathology in secondary syphilis is summarised, and a review of the literature regarding syphilitic granulomatous hepatitis presented.

Kerion--clinical spectrum in nine cases

The clinical features, microbiology and outcome of nine cases of kerion are reviewed. The aetiology of this uncommon condition, and the role of various therapeutic modalities are discussed. Clinicians need to be aware of the varying presentations of inflammatory fungal disease to avoid misdiagnosis as bacterial infection.

Prevention of early recurrence of high risk malignant melanoma by coumarin. Irish Melanoma Group

Coumarin (1,2-benzopyrone) as a daily oral dose of 50 mg was evaluated in a multicentre prospectively randomized, double-blind, placebo-controlled trial to prevent early recurrence of malignant melanoma TNM Stage IB (Breslow thickness greater than 1.70 mm) and Stage II. Intake for the trial started in 1984 and was stopped prematurely, after review, in 1987. There were two recurrences in 13 treated patients and 10 in 14 controls which was significant (P 0.01). The sites of the metastases differed in each group, being local and in bone in the treated group, and in lymph nodes, skin and lung in the control group. There were no toxic effects associated with coumarin treatment and all patients without recurrence are now receiving coumarin.

Hidradenitis suppurativa. Glucose tolerance, clinical, microbiologic, and immunologic features and HLA frequencies in 27 patients

Glucose tolerance, lymphocyte populations, and HLA types were studied in 27 patients with untreated hidradenitis suppurativa; 18 of these patients had a negative history for acne vulgaris. Six patients (22%) had an increased incidence of impaired glucose tolerance. We failed to confirm a previous report of high incidence of flat glucose tolerance curves. The frequency of HLA-A and HLA-B antigen loci and the median values of peripheral blood T lymphocytes were similar to the control population. However, seven patients with moderate or severe clinical disease had a marked reduction in T lymphocytes and these patients had an increased frequency of the HLA antigens, A1 and B8. These results suggest that T lymphocytes may play a role in the pathogenesis of hidradenitis suppurativa and that HLA-A1 and HLA-B8 may predispose the patient to more severe disease, but further research is necessary to clarify this.

Psychogenic skin disease: a review of 35 cases

In three years of clinical practice, the authors saw 35 cases of dermatological disorders of strictly psychological origin--8 patients with dermatitis artefacta, 8 with delusional parasitosis, and 19 who presented with skin complaints but showed no dermatological pathology ('dermatological non-disease'). All but two initially presented for dermatological opinion rather than psychiatric assessment, and 12 refused psychiatric referral. Demographic and clinical details of all 35 cases are given, including possible related factors, course, treatment, and outcome, and the cases are discussed in the context of the existing literature. Liaison between dermatologists and psychiatrists is strongly advocated.

Direct immunofluorescence of normal skin in rheumatoid arthritis

The clinical significance of previously described immunoglobulin and complement deposition in the superficial dermal vessel walls of patients with rheumatoid arthritis is unknown. In the present study, skin biopsies were obtained from the normal forearm and buttock of 48 unselected patients with rheumatoid arthritis and were examined by direct immunofluorescence (IF) for the presence of immunoglobulin (IgG,A,M) and complement (C3) in the vessel walls. Deposits of C3, IgM or IgG were detected in 10 patients. Five patients had deposits at the forearm sample alone, four patients had deposits at both biopsy sites, while one patient was positive at the buttock alone. Clinical features were similar in patients with and without vessel IF. However, patients with IF were significantly more seropositive with lower levels of complement and raised levels of serum IgA and IgM. There was also an increased level of circulating IgG immune complexes in these patients. Further analysis following exclusion of seronegative patients revealed similar results. This study suggests that the presence of vessel IF identifies a subgroup of patients who have evidence of more severe immunological disturbance.

Solitary familial desmoplastic trichoepithelioma. A study by conventional and electron microscopy

Solitary desmoplastic trichoepitheliomas from a mother and two daughters were studied by conventional and electron microscopy. Differential diagnosis by conventional microscopy is briefly discussed. The lesions consisted of cords and nests of basaloid cells set in fibrotic stroma and confined to the dermis. In addition, each lesion contained horn cysts and focal areas of calcification. Horn cysts were occasionally identified in continuity with infundibulae of normal hair follicles. Semithin sections showed cords and nests of cells in continuity with the horn cysts. Ultrastructurally, a continuous basal lamina surrounded the cords of basaloid cells and connected to horn cysts. Individual cells contained tonofilaments and were attached to adjacent cells by desmosomes. Hemidesmosomes were present at peripheral cell membranes bounded by basal lamina. There was no glandular differentiation. Our observations by electron and conventional microscopy support a conclusion that desmoplastic trichoepitheliomas are derived from hair appendages.

Circulating immune complexes in systemic scleroderma and generalized morphea

There is growing evidence that pathologic changes in the vascular system are implicated in the pathogenesis of systemic scleroderma. It has been suggested that immune complex deposition may be responsible for such changes. We measured circulating immune complexes in 10 patients with severe systemic scleroderma, 1 of whom had clinical evidence of renal disease, and in 3 patients with generalized morphea. None of the patients had significantly elevated levels. Our findings suggest that although circulating immune complexes are of diagnostic and prognostic value in other collagen vascular diseases, they do not play a major role in the pathogenesis of systemic scleroderma in patients who lack clinical evidence of renal disease.