Intranodal palisaded myofibroblastoma
Encyclopedia
Intranodal palisaded myofibroblastoma, abbreviated IPM, is a rare primary tumour of lymph node
s, that classically presents as an inguinal
mass.
It afflicts predominantly males of middle age.
. They usually are found in the inguinal region and grow slowly.
The signs and symptoms are non-specific, i.e. it is not possible to diagnose an IPM from the symptoms and manner in which they present.
The main (clinical) differential diagnosis of IPM is metastatic
cancer
, e.g. squamous cell carcinoma
, malignant melanoma, adenocarcinoma
.
by a pathologist.
They have a rim of peripheral lymphoid tissue (remnant of a lymph node
) and consist of spindle cells with nuclear
palisading
. Red blood cell
extravasation
is common and blood vessel
s surrounded by collagen
with (fine) peripheral spoke
s (amianthoid fibers) are usually seen.
Immunostains for smooth muscle
actin
and cyclin D1
are characteristically positive. The main histologic differential diagnosis
is schwannoma
.
Lymph node
A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
s, that classically presents as an inguinal
Inguinal
In human anatomy, the inguinal region refers to either the groin or the lower lateral regions of the abdomen. It may also refer to:* Conjoint tendon, previously known as the inguinal aponeurotic falx, a structure formed from the transversus abdominis insertion into the pecten pubis* Granuloma...
mass.
It afflicts predominantly males of middle age.
Signs and symptoms
IPMs present as painless lymphadenopathyLymphadenopathy
Lymphadenopathy is a term meaning "disease of the lymph nodes." It is, however, almost synonymously used with "swollen/enlarged lymph nodes". It could be due to infection, auto-immune disease, or malignancy....
. They usually are found in the inguinal region and grow slowly.
The signs and symptoms are non-specific, i.e. it is not possible to diagnose an IPM from the symptoms and manner in which they present.
The main (clinical) differential diagnosis of IPM is metastatic
Metastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
, e.g. squamous cell carcinoma
Squamous cell carcinoma
Squamous cell carcinoma , occasionally rendered as "squamous-cell carcinoma", is a histologically distinct form of cancer. It arises from the uncontrolled multiplication of malignant cells deriving from epithelium, or showing particular cytological or tissue architectural characteristics of...
, malignant melanoma, adenocarcinoma
Adenocarcinoma
Adenocarcinoma is a cancer of an epithelium that originates in glandular tissue. Epithelial tissue includes, but is not limited to, the surface layer of skin, glands and a variety of other tissue that lines the cavities and organs of the body. Epithelium can be derived embryologically from...
.
Diagnosis
IPMs are diagnosed by examination of the tissueTissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
by a pathologist.
They have a rim of peripheral lymphoid tissue (remnant of a lymph node
Lymph node
A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
) and consist of spindle cells with nuclear
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
palisading
Palisade
A palisade is a steel or wooden fence or wall of variable height, usually used as a defensive structure.- Typical construction :Typical construction consisted of small or mid sized tree trunks aligned vertically, with no spacing in between. The trunks were sharpened or pointed at the top, and were...
. Red blood cell
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...
extravasation
Extravasation
Extravasation is the accidental administration of intravenously infused medicinal drugs into the surrounding tissue, either by leakage , or direct exposure...
is common and blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
s surrounded by collagen
Collagen
Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...
with (fine) peripheral spoke
Spoke
A spoke is one of some number of rods radiating from the center of a wheel , connecting the hub with the round traction surface....
s (amianthoid fibers) are usually seen.
Immunostains for smooth muscle
Smooth muscle
Smooth muscle is an involuntary non-striated muscle. It is divided into two sub-groups; the single-unit and multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous system innervates a single cell within a sheet or bundle and the action potential is propagated by...
actin
Actin
Actin is a globular, roughly 42-kDa moonlighting protein found in all eukaryotic cells where it may be present at concentrations of over 100 μM. It is also one of the most highly-conserved proteins, differing by no more than 20% in species as diverse as algae and humans...
and cyclin D1
Cyclin D1
G1/S-specific cyclin-D1 is a protein that in humans is encoded by the CCND1 gene.Immunohistochemical staining of cyclin D1 antibodies is used to diagnose mantle cell lymphoma.-Interactions:...
are characteristically positive. The main histologic differential diagnosis
Differential diagnosis
A differential diagnosis is a systematic diagnostic method used to identify the presence of an entity where multiple alternatives are possible , and may also refer to any of the included candidate alternatives A differential diagnosis (sometimes abbreviated DDx, ddx, DD, D/Dx, or ΔΔ) is a...
is schwannoma
Schwannoma
A schwannoma is a benign nerve sheath tumor composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral nerves....
.