Kinds of Diagnoses | Mark A. Hurt, MD

What kinds of diagnoses do you make routinely?

The most common, in a given day's work, are:

- Squamous cell carcinoma (including solar [actinic] keratoses; a malignant epithelial neoplasm)
- Basal cell carcinoma (also known as trichoblastic carcinoma, a malignant epithelial neoplasm)
- Seborrheic Keratosis (a benign epithelial neoplasm)
- Keratoacanthoma (a kind of epithelial hyperplasia that often simulates squamous cell carcinoma)
- Wart or verruca or condyloma (a kind of epithelial hyperplasia caused by human papillomavirus infection)
- Cysts
 
- Melanocytic nevus (a benign proliferation of melanocytes - some are hamartomas; others are benign neoplasms)
- Melanoma (a malignant proliferation of melanocytes, which is a type of sarcoma)
 
- Psoriasis (a kind of genodermatosis)
- Spongiotic dermatitis (referred to often as "eczema", which is an imprecise way to refer to specific diseases that manifest themselves histologically as spongiosis)
- Hypersensitivity reactions (inflammatory reactions caused by a sensitizing agent)
- Allergic reactions (inflammatory)
- Infections (the cause is known, an organism, but the result is usually an inflammatory response in the skin)
- Lupus erythematosus (an autoimmune disorder that often manifests as an inflammatory pattern in the skin)
 
 
 
Broadly, with some clarifications, all diseases of skin are dermatoses, which means, simply, "a disease of the skin".  Yet, most dermatopathologists separate skin diseases into three main categories:
 
1.  Inflammatory Diseases (including autoimmune disease and infectious disease)
2.  Simulators of Inflammatory Diseases (including metabolic diseases)
3.  Non-inflammatory cellular proliferations (including neoplasms and some simulators of inflammatory disease).
 
 
It is not completely accurate to attribute the term "neoplasm" to all non-inflammatory cellular proliferations.  A neoplasm means a "new growth", in contrast with, for instance, an abnormal proliferation of cells identified at or near birth that simulates the normal tissue at the given location, but is positioned abnormally (hamartoma).  All lesions that present clinically as tumors (i.e., papules, nodules, and larger masses) are not neoplasms.  As a rule, they are divided into the following categories:
 
1.  Malformation (congenital, benign)
2.  Cyst
3.  Hyperplasia (stimulus dependent, benign)
4.  Hamartoma (congenital or tardive, benign)
5.  Neoplasm (both stimulus independent, benign & malignant)
 
As a rule, neoplasms are divided into epithelial (from cells lining surfaces or ducts) and parenchymal (everything else, including supporting stroma, blood vessels, neural tissue, melanocytes etc).  Malignant epithelial neoplasms are termed "carcinomas", while malignant non-epithelial neoplasms are termed "sarcomas".