Cutaneous-malignancy and leprosy. Report of a patient with Mycobacterium leprae and basal cell carcinoma concurrently present in the same lesion

Dual Nature of Relationship between Mycobacteria and Cancer

Although the therapeutic effect of mycobacteria as antitumor agents has been known for decades, recent epidemiological and experimental studies have revealed that mycobacterium-related chronic inflammation may be a possible mechanism of cancer pathogenesis. Mycobacterium tuberculosis and non-tuberculous Mycobacterium avium complex infections have been implicated as potentially contributing to the etiology of lung cancer, whereas Mycobacterium ulcerans has been correlated with skin carcinogenesis. The risk of tumor development with chronic mycobacterial infections is thought to be a result of many host effector mechanisms acting at different stages of oncogenesis. In this paper, we focus on the nature of the relationship between mycobacteria and cancer, describing the clinical significance of mycobacteria-based cancer therapy as well as epidemiological evidence on the contribution of chronic mycobacterial infections to the increased lung cancer risk.

Lepromatous leprosy, melanoma, and basal cell carcinoma: clinical-histopathologic association

Cutaneous neoplasms frequently occur in leprosy, but there are few reports of the coexistence of leprosy and basal cell carcinoma in the same lesion. This case reports a 49-year-old male with an ulcerated plaque on the right lateral nasal wall, bright papules on the sternal region, and a blackened plaque on the right temporal region. The nasal and temporal lesions were diagnosed by histopathology as basal cell carcinoma and melanoma, respectively. The sternal lesions were excised with the repair of the “dog ear” which histopathological examination showed macrophages in the dermis parasitized with acid-fast bacilli, confirming the diagnosis of lepromatous leprosy with Fite-Faraco staining. This case report highlights the importance of referring the dog-ear specimen for histopathologic analysis.

Neoplastic cells parasitized by Mycobacterium leprae: report of two cases of melanocytic nevus and one of basal cell carcinoma

Background

Leprosy is a major public health concern in many developing countries. Mycobacterium leprae (M. leprae), the causative agent of leprosy, has the ability to parasitize different types of human cells and tissues. In this article, the uncommon parasitism of nevus and neoplastic and epithelial cells by M. leprae are described using histological sections doubly stained by Fite-Faraco (FF) and immunohistochemistry (IHC), respectively.

Case presentation

Three patients with borderline-lepromatous and lepromatous leprosy underwent excision of melanocytic nevi (cases 1–2) and basal cell carcinoma (case 3). Histological sections confirmed the clinical diagnosis of melanocytic nevus and basal cell carcinoma, but leprosy lesions were evident in adjacent tissues. FF staining and IHC (CD68, Melan A, and 34βE12) demonstrated the presence of bacilli within the nevus cells and also in the epithelial cells of the basal cell carcinoma.

Conclusions

M. leprae has the ability to parasitize different types of cells, including neoplastic cells. Pathologists working in settings where leprosy is endemic should be aware that some cutaneous biopsy specimens may also present with leprosy findings.

Basal Cell Carcinoma Associated with Secondary Localized Cutaneous Amyloid Deposits: Case Report and Review

Amyloid deposition has been observed in tissue specimens of basal cell carcinomas. A 68-year-old man with a nodular basal cell carcinoma on his left arm near the elbow is described; microscopic evaluation of the biopsy tissue specimen shows not only nodular aggregates and strands of atypical basaloid tumor cells but also marked deposition of amorphous amyloid material in the stroma between the aggregates of basal cell carcinoma. Including the man in this report, there are additional individual descriptions of patients whose basal cell carcinomas have amyloid deposits in the adjacent stroma or within the tumor aggregates or both. In addition, several retrospective pathology investigations have evaluated the features of this phenomenon. The incidence of basal cell carcinoma with amyloid deposition, in the English literature, ranges from 11% to 75%; however, it is possible that staining technique or tumor subtype or quantity of amyloid present may account for the lower detection of amyloid observed by some of the researchers. Amyloid in basal cell carcinoma specimens was observed to be present more frequently in older patients who had tumors with less aggressive histology patterns. Nodular basal cell carcinoma was the most common subtype of tumor with amyloid deposits whereas superficial basal cell carcinoma was the least frequent subtype. The amyloid deposits were usually identified on hematoxylin and eosin-stained sections and confirmed by using stains that allowed for easier visualization of the amyloid. The amyloid deposits were most commonly located in the stroma between the tumor aggregates; other locations included the papillary dermis above the carcinoma, the dermis at the advancing edge of the tumor and within the aggregates of basal cell carcinoma. Many of the basal cell carcinomas with amyloid deposits, similar to the reported patient, also contained solar elastosis. The origin of the amyloid deposition in these tumors is secondary amyloid AA protein from keratin derived from the epithelial cells overlying the basal cell carcinomas. The presence of amyloid deposition does not alter the management of these basal cell carcinomas; the treatment of the tumor is the same as when the basal cell carcinoma does not contain amyloid deposition.

Basal Cell Carcinoma: A Patient and Physician's Experience

In this article, the first coauthor, a patient with a basal cell carcinoma on her upper lip, discusses her experience with Mohs micrographic surgery for the treatment of the skin cancer. The second coauthor, who is the patient's physician (a dermatologist who shares her last name but is not a relative), diagnosed her skin cancer and referred her for Mohs surgery. The third coauthor, who is the patient's son and not only a dermatologist, but also a dermatopathologist and a Mohs surgeon (and also shares her last name), summarizes the presentation and treatment of the basal cell carcinoma.

Optical imaging: bacteria, viruses, and mammalian cells encoding light-emitting proteins reveal the locations of primary tumors and metastases in animals

Early detection of tumors and their metastases is crucial for the prognosis of cancer treatment. Traditionally, tumor detection is achieved by various methods, including magnetic resonance imaging and computerized tomography. With the recent cloning, cellular expression, and real-time imaging of light-emitting proteins, such as Renilla luciferase (Ruc), bacterial luciferase (Lux), firefly luciferase (Luc), green fluorescent protein (GFP), or Ruc-GFP fusion protein, significant efforts have been focused on using these marker proteins for tumor detection. It has also been demonstrated that certain bacteria, viruses, and mammalian cells (BVMC), when administered systemically, are able to gain entry and replicate selectively in tumors. In addition, many tissue/tumor specific promoters have been cloned which allow transgene expression specifically in tumor tissues. Therefore, when light-emitting protein encoded BVMC are injected systemically into rodents, tumor-specific marker gene expression is achieved and is detected in real time based on light emission. Consequently, the locations of primary tumors and previously unknown metastases in animals are revealed in vivo. In the future it will likely be feasible to use engineered light-emitting BVMC as probes for tumor detection and as gene-delivery vehicles in vivo for cancer therapy.