Blastic Plasmacytoid Dendritic Cell Neoplasm: A Case Series and Review

ABSTRACT

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy that frequently has cutaneous manifestations. The diagnosis can be a challenge because of its heterogenous clinical presentation, ranging from a brown or violaceous solitary nodule or patch to mixed, disseminated lesions. Furthermore, BPDCN tumor cells express immunohistochemical markers in common with acute myeloid leukemia, which can lead to misdiagnosis. Timely diagnosis requires awareness of its cutaneous manifestations and unique histopathology and immunophenotype. We present a case series of patients diagnosed with BPDCN and review the cutaneous and histopathologic characteristics of this uncommon entity.

What lies beneath: Cutaneous involvement of mantle cell lymphoma underlying an insect-bite-like reaction

Mantle cell lymphoma (MCL) is an uncommon subtype of mature B-cell non-Hodgkin lymphoma characterized by specific morphologic, immunophenotypic, and genetic characteristics, namely the t(11;14)(q13;q32) chromosomal translocation with resultant cyclin D1 overexpression. MCL has a generally aggressive course and is often widely disseminated at the time of diagnosis. Skin involvement is exceedingly rare and is seldom the first manifestation of MCL. We present a case of MCL in an 84-year-old man with cutaneous involvement as the first manifestation, discovered incidentally after biopsy of a persistent nodule believed to be an insect bite. This case not only serves to raise awareness of the possibility of MCL presenting in the skin but also to point out that MCL can have lesions with both an insect-bite-like reaction and a deeper dermal MCL infiltrate.

An unusual case of cutaneous Waldenström macroglobulinemia with the MYD88 L265P mutation

Waldenström macroglobulinemia is a lymphoplasmacytic lymphoma with bone marrow involvement and a monoclonal IgM gammopathy. Infiltration of the skin by neoplastic cells is very rare, and it can be difficult to distinguish from marginal zone lymphoma. The MYD88 L265P mutation is strongly associated with Waldenström macroglobulinemia, and it may be helpful in differentiating the two disorders, although the presence of this mutation is not specific, and other factors must be considered when making the final diagnosis. We present a diagnostically challenging case of cutaneous Waldenström macroglobulinemia in which the MYD88 L265P mutation was identified in the skin but not in the bone marrow, due to a low tumor burden.

Sustained rescue of prefrontal circuit dysfunction by antidepressant-induced spine formation

The neurobiological mechanisms underlying the induction and remission of depressive episodes over time are not well understood. Through repeated longitudinal imaging of medial prefrontal microcircuits in the living brain, we found that prefrontal spinogenesis plays a critical role in sustaining specific antidepressant behavioral effects and maintaining long-term behavioral remission. Depression-related behavior was associated with targeted, branch-specific elimination of postsynaptic dendritic spines on prefrontal projection neurons. Antidepressant-dose ketamine reversed these effects by selectively rescuing eliminated spines and restoring coordinated activity in multicellular ensembles that predict motivated escape behavior. Prefrontal spinogenesis was required for the long-term maintenance of antidepressant effects on motivated escape behavior but not for their initial induction.

Multiple flat-topped scaly violaceous papules

Epidermodysplasia verruciformis (EV) is an autosomal recessive genodermatosis characterized by susceptibility to beta-genus human papillomavirus (HPV) infection. Owing to TMC6/EVER1 and TMC8/EVER2 mutations that lead to abnormal transmembrane channels in the endoplasmic reticulum involved in immunological pathways, keratinocytes cannot combat infection from non-pathogenic HPV strains. Mutations involving RHOH, MST-1, CORO1A, and IL-7 have also been associated with EV in patients without TMC6 or TMC8 mutations. We highlight a 27-year-old man with multiple violaceous flat-topped papules with scale and irregular borders distributed on his chest, extremities, abdomen, and back. The striking physical examination and the subsequent biopsy findings of enlarged nests of cells in the granular and spinous layers with blue-gray cytoplasm and keratohyaline granules confirmed the diagnosis. We conclude with a brief discussion on the differential diagnosis, which includes confluent and reticulated papillomatosis, Darier disease, and disseminated superficial actinic porokeratosis.

Successful treatment of facial papules with electrodessication in a patient with Birt-Hogg-Dubé syndrome

We report a case of a 51-year-old Hispanic female who presented with a several year history of multiple flesh colored papules of cosmetic concern on the nose and medial cheeks. Biopsies revealed fibrofolliculoma and trichodiscoma. The patient was referred for genetic testing and was found to be positive for the FLCN gene defect, confirming a diagnosis of Birt-Hogg-Dubé syndrome. Further work-up with screening renal ultrasound and CT scan of the thorax and abdomen was unrevealing. For treatment of these skin lesions, dermasanding was attempted initially with only minimal benefit. She subsequently had multiple lesions treated with electrodessication at a low setting and was very pleased with the results. Curettage was not performed and importantly, there has yet to be a recurrence of lesions treated with only hyfrecation.

Imiquimod 5% cream as adjunctive therapy for primary, solitary, nodular nasal basal cell carcinomas before Mohs micrographic surgery: a randomized, double blind, vehicle-controlled study

BACKGROUND

Imiquimod 5% cream is currently approved for treatment of nonfacial, superficial basal cell carcinomas (BCCs). Topical imiquimod might be a reasonable candidate for adjunctive therapy of nodular, nasal BCCs before Mohs surgery.

OBJECTIVE

To observe the effectiveness of imiquimod 5% cream in reducing the number of Mohs stages, defect size, cost of Mohs surgery, and reconstruction.

METHODS

Patients applied the study medication nightly for 6 weeks with occlusion followed by a 4-week rest period before Mohs surgery was performed.

RESULTS

No differences were demonstrated in the number of Mohs stages, defect sizes, or costs between the two groups, possibly because of our small sample size. Only five of 12 patients (42%) in the treatment group were found histologically clear of tumor (complete responders).

CONCLUSION

Imiquimod 5% cream was not helpful as an adjunctive treatment of nodular, nasal BCCs before Mohs surgery, but a larger study might show a benefit. Clearance of nodular, nasal BCCs treated with imiquimod prior to Mohs surgery was less than described in previous studies. Nasal BCCs may be more resistant to imiquimod treatment. Local inflammatory reactions limit imiquimod's usefulness in this setting. Histologic assessment of nasal BCCs treated with imiquimod is recommended.

Flexion contractures of the knee following poliomyelitis

Contractures of the knee after poliomyelitis are common in children in developing countries and treatment, particularly that of severe contractures, presents a surgical challenge. This paper describes a new method for correcting contractures of the knee. Mild contractures need manipulation only and a plaster cast. Moderate contractures are treated by a partial soft-tissue release of the hamstrings and fascia lata followed by gradual stretching of the remaining soft-tissues by manipulation and plaster. Where the contracture is severe, skeletal traction is used through Steinmans pins inserted into the tibia and os calcis. One hundred and thirty-six knees with varying degrees of contracture were treated by these methods. Full correction was achieved and then maintained by plaster immobilisation, physiotherapy and calipers. This prevented recurrence during an average follow-up period of two and a half years. The severity of the contracture of the knee was in direct proportion to the severity of associated flexion-abduction contractures at the hip and equinus deformity at the ankle, the degree of muscle imbalance. All of the contractures of the hip and some of the ankle (46.8%) needed simultaneous operative correction. The basic method is technically simple, requires no special equipment and the results recommend its use particularly in developing countries.

Condylectomies for prolonged bilateral temporomandibular dislocation

An unusual case of old unreduced bilateral temporomandibular joint (TM joint) dislocation is presented. Extensive reviews of English and Japanese literature described managing such cases by various methods including closed or open joint reduction. However, successful bilateral condylectomies carried out in seven months old dislocation, provided free range of painless movements and good stability. As there is no possibility of redislocation or painful degenerative arthritis following this procedure, it's role in African environment is described.

Homologous nerve transplantation and immunosuppression in rabbits

Homologous nerve transplantation is a logical method of bridging major nerve defects but its usefulness is negated by immune rejection. The discovery of an effective method of immunosuppression would allow utilisation of this technique. The present study compared the effects of irradiation, dexamethasone, and chloramphenicol in homologous nerve transplantation. Segments of homologous sciatic nerve were implanted into the dorsal subcutaneous (s.c.) tissues of 83 rabbits. In one group the graft was irradiated in vitro before implantation and in other groups the recipient rabbits received either dexamethasone or chloramphenicol systemically for up to 3 weeks after implantation. The transplanted nerve segments were removed at different time intervals and examined for signs of rejection. In conclusion, rejection commenced during the 1st week and peaked during the 3rd week. In the control group without immunosuppressant, all animals exhibited severe rejection. Both pre-implantation irradiation of the grafts at 450 rad dose-level and systemic chloramphenicol at 100 mg/kg/day were found to completely suppress rejection. These methods were considerably more effective than conventional steroids. Thus, the idea of a "nerve bank" is postulated.

Giant-cell tumour of the tendon sheath

An unusual case of giant-cell tumours of the tendon sheath (syn. Pigmented villonodular tenosynovitis or fibrous xanthoma) of a long thumb flexor is presented. The unusual features are: two distinctly different tumours of almost similar size and shape arising from the tendon sheath at its either ends but with a segment of normal tendon sheath in between and presence of early malignant changes in the distal tumour with a benign proximal one, confirmed microscopically. Lastly, radiograph showed definite bony involvement in the proximal phalanx of the thumb. On extensive review of the literature, I found reports of rare presentation of malignant changes and bony erosion, but none had these various features.